Dam Maintenance Program

Transcription

1 June 2011 Dam Maintenance Program Draft Program Environmental Impact Report (PEIR) 5750 Almaden Expressway San Jose, CA Contact: Scott Akin SCH#

2 TABLE OF CONTENTS Page EXECUTIVE SUMMARY... ES-1 Proposed Project... ES-1 Anticipated Environmental Impacts... ES-2 CHAPTER 1. INTRODUCTION Program Overview DMP Program Objectives California Environmental Quality Act (CEQA) Process Regulatory Use of the PEIR and Permits Public Involvement Public and Agency Concerns and Areas of Known Controversy Issues to Be Resolved Topics Not Covered in Detail in This EIR CHAPTER 2. PROJECT DESCRIPTION Introduction Maintenance Activities Dam Maintenance Process and Implementation Environmental Protection Policies and Practices CHAPTER 3. SETTING AND IMPACT ANALYSIS Setting and Impact Analysis Introduction Vegetation and Habitat Wildlife Hydrology and Water Quality Hazards, Hazardous Materials, and Human Health and Safety Cultural Resources Geology, Soils, and Mineral Resources Noise Air Quality Traffic and Transportation Recreation Aesthetics and Visual Resources Utilities and Services Systems CHAPTER 4. CUMULATIVE IMPACTS Introduction Approach to Cumulative Impacts Cumulative Impacts on Environmental Parameters June 2011 Page i

3 Page CHAPTER 5. GROWTH-INDUCING AND SIGNIFICANT UNAVOIDABLE EFFECTS Introduction Growth-Inducing Impacts Significant, Unavoidable Effects Potentially Significant, Unavoidable Effects Subject to Future Project-Level Review CHAPTER 6. PROJECT ALTERNATIVES Introduction Feasible Alternatives Alternatives Considered But Rejected Environmentally Superior Alternative CHAPTER 7. LIST OF PREPARERS AND CONSULTATIONS List of Preparers CHAPTER 8. BIBLIOGRAPHY TABLES Table ES-1: Significant Project Impacts With Mitigation Measures... ES-2 Table 1.4-1: Permits and Approvals Necessary for Dam Maintenance Activities Table 2.2-1: Proposed Vegetation Management Methods Table 2.2-2: Application Rate for Herbicides Used by the District Table 2.23: Proposed Burrowing Rodent Control Methods Table 3.2-1: Soils Underlying the Project Areas Table 3.2-2: Natural Communities in the Project Area Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Table 3.2-4: Special Status Plant Occurrence Information 2006/2008 Surveys Table 3.2-5: Summary of Rare Plant Occurrences and Potential Impacts by Watershed Table 3.2-6: Summary of Analysis of Impacts and Mitigation to Special Status Plant Populations Table 3.2-7: Sensitive Natural Communities Within the Project Area Table 3.2-8: Summary of Sensitive Natural Community Potential Impacts by Watershed Table 3.3-1: Special Status Animal Species Documented Within the Project Vicinity Table 3.3-2: Potential Sources of Supplemental Water Table 3.3-3: Summary of Impacts and Mitigation Measures for Reservoir Dewatering June 2011 Page ii

4 Page Table 3.3-4: CRLF/CTS/FYLF/WPT Presence at Dams Table 3.3-5: Characterization of Vegetation Management Impacts to Oak and Conifer Woodlands Table 3.4-1: Summary of 303(d) Listings for DMP Potential Receiving Waters Table 3.5-1: Top 10 Pesticides Recorded Use in Santa Clara County in Table 3.5-2: Toxicity of District Proposed Herbicides to Humans and Animals and Their Environmental Fate Table 3.5-4: Toxicity of District Proposed Rodenticides to Humans and Animals and Their Environmental Fate Table 3.6-1: Construction Date, Engineers, and Construction Companies for Historic Dams Table 3.6-2: Archaeological Buried Site Sensitivity Classification Based on Geomorphic Mapping Table 3.7-1: Characteristics of Soils by Topographic Region Table 3.7-2: Maximum Credible Earthquakes on Nearby Faults Table 3.7-3: Local Faults Near Project Dams Table 3.8-1: Definition of Acoustical Terms Used in This Report Table 3.8-2: Typical Noise Levels in the Environment Table 3.8-3: Recommended Maximum Interior Noise Levels for Intermittent Noise Table 3.8-4: Sensitive Receptors Near District Dams Table 3.8-5: Dam Maintenance Equipment Noise Generation Levels by Equipment and Activity Table 3.8-6: Noise Regulations, Policies and Guidelines by Jurisdiction and Dam Table 3.8-7: Peak Particle Velocities at Defined Distances Table 3.9-1: State and Federal Air Quality Standards Table 3.9-2: Average Emissions From the DMP and BAAQMD Thresholds for Criteria Air Pollutants Table : Major Highways and Local Roads That Provide Access to Dams Table : Signalized Street and Intersection LOS Criteria Table : Peak Directional Traffic Volumes and Corresponding LOS for Major Highway Segments to Access Dams Table : Potential for Emergency Access Hazards by Dam Table : Parks Surrounding District Reservoirs Table : Scenic Roads and Distance From Project Area Table : Annual Water Supply and Distribution for Calendar Years 2007 Through June 2011 Page iii

5 Page FIGURES Figure 2.1-1: SCVWD Dam Locations Figure 3.4-1: Dam Locations by Watershed Figure 3.5-1: Wildland Fire Hazard in Project Area Figure 3.7-1: Serpentine Bed Rock and Soil in Project Area Figure 3.7-2: Major Faults and Age of Faults in the San Francisco Bay Area Figure 3.7-3: Liquefaction in Project Area Figure 3.7-4: Landslide Hazard Zones in the Project Area Figure : Major Highways and Roads in the Project Region Figure : Northern Santa Clara County Average Daily Traffic (ADT) Figure : Southern Santa Clara County Average Daily Traffic (ADT) Figure : Dam Sites in Regional Parks APPENDICES Appendix I Appendix II Appendix III Appendix IV Appendix V Appendix VI Appendix VII Appendix VIII Appendix IX Appendix X Appendix XI Notice of Preparation and Comment Letters Additional Species Information Biological Resource Maps Figure Set III-1: Biotic Habitats by Dam Figure Set III-2: Special Status Plants Figure Set III-3: Critical Habitat Figure Set III-4: Locations of Dusky-Footed Woodrat Nests Glossary of Terms Mitigation Monitoring and Reporting Program (MMRP) Dam Maintenance Program (DMP): Detailed Description of Activities Maps Showing Location of Dam Facilities Master List of Activities Burrow Collapse Protocol Greenhouse Gas Emissions (GHG) Calculation EPA Injunction Chemicals June 2011 Page iv

6 EXECUTIVE SUMMARY This document is the draft Program Environmental Impact Report (PEIR) analyzing the environmental effects of the s (District s) proposed Dam Maintenance Program (DMP). The DMP defines activities associated with maintenance and repair of its dam facilities. The District owns 14 regulated water retention facilities that are operated under licenses granted by the State of California Department of Water Resources, Division of Safety of Dams (DSOD). Twelve of these facilities are earthen dams with regulated reservoirs, one is an earthen dam with a covered reservoir at a water treatment plant, and one is an in-stream retention facility to enhance groundwater recharge capabilities. This EIR has been prepared in compliance with the California Environmental Quality Act (CEQA) to provide an objective analysis to be used by the District, as the Lead Agency, as well as other agencies and the public, in their considerations regarding the implementation, rejection, or modification of the DMP as proposed. The EIR itself does not determine whether the DMP will be implemented or not; it only serves as an informational document in the decision-making process. Following public review of this document, the District s Board of Directors will use the information it contains, together with other information, comments submitted by other agencies and the public during the review period, to evaluate if and how the DMP should proceed. Resource agencies such as the U.S. Army Corps of Engineers, California Department of Fish and Game, Regional Water Quality Control Boards, and U.S. Fish and Wildlife Service will use this analysis in assessing whether to grant permits necessary for the DMP. PROPOSED PROJECT Maintenance of dam appurtenances is necessary to ensure the safe and efficient working of the dam. As many as 67 different maintenance activities are performed at the dams, with varying potential for environmental effects. These activities are divided into the four main categories and 14 subcategories below. Surfaces and/or Earth Work: Any work on the natural environment at the surface Vegetation management Burrowing rodent control Access road and boat ramp work Erosion Control/bank stabilization/drainage Embankment repair (cracking and slumping) Trash and debris removal Maintenance of Dam Appurtenances and Equipment: Any work on dam equipment, mechanical equipment, monitoring instruments, or supervisory control and data acquisition systems. Inlet/outlet Valve systems and hydraulic systems Sediment removal around intake structures and hydraulic lines Concrete structure repairs, Replacement and Cleaning (including weep holes) Seepage systems (weirs and piping) Other appurtenances (piezometers, electrical systems, fences, etc.) June 2011 Page ES-1

7 Executive Summary Inspections, Monitoring and Exploratory Work Exploratory field investigations DSOD and other inspections Reservoir Dewatering Most dams will require all of the identified maintenance activities at some point in time, although activities will vary based on the dam s age, design, and location. A more detailed description of the proposed DMP is provided in Chapter 2. ANTICIPATED ENVIRONMENTAL IMPACTS SIGNIFICANT IMPACTS AND PROPOSED MITIGATION Table ES-1 summarizes the DMP s potential for significant impacts on the environment, along with the mitigation measures identified to ensure that all impacts are reduced to a less than significant level. For a complete description of potential impacts and recommended mitigation measures, please refer to the specific discussions in Sections 3.2 though Table ES-1: Significant Project Impacts With Mitigation Measures Impact Vegetation and Habitat Disturbance or loss of special status plant populations Degradation of serpentine-associated natural communities Mitigation MM Vegetation-1: Conduct periodic botanical surveys. MM Vegetation-2: Protect, through land acquisition or a conservation easement, a population of equal or greater size and health. MM Vegetation-6: If riparian or sensitive plant dieback is attributed to dewatering, the resource will be restored if not recovered within two growing seasons. MM General-1: Conduct a project level CEQA review of reservoir dewatering. MM General-2: Consult with CDFG and any other applicable resource agency and obtain all necessary permits. MM General-3: Prepare a reservoir specific dewatering plan. MM General-4: Limit crushing of woody debris to previously disturbed areas. MM Vegetation-3: Protect or restore, through land acquisition or a conservation easement, comparable serpentine habitat to mitigate for the permanent loss of sensitive habitat using a 3:1 mitigation ratio. June 2011 Page ES-2

8 Executive Summary Table ES-1: Significant Project Impacts With Mitigation Measures Impact Degradation of riparian habitat Loss or disturbance of wetlands Wildlife Disturbance, injury or mortality of steelhead or Chinook salmon Disturbance, injury or mortality of California Tiger Salamander, California Red-Legged Frog, Foothill Yellow-Legged Frog, and Western Pond Turtle Mitigation MM Vegetation-4: Protect or restore, through land acquisition or a conservation easement, comparable riparian habitat to mitigate for the permanent loss of sensitive habitat using a 3:1 mitigation ratio. MM Wildlife-1: A flow by-pass system shall be installed and implemented for any activity that requires closing of a dam s inlet or outlet valves where the closure would result in the interruption of flow downstream from the dam. MM General-4: Limit crushing of woody debris to previously disturbed areas. MM Vegetation-5: Protect or restore, through land acquisition or a conservation easement, comparable wetland habitat to mitigate for the permanent loss of sensitive habitat using a 3:1 mitigation ratio. MM Wildlife-1: A flow by-pass system shall be installed and implemented for any activity that requires closing of a dam s inlet or outlet valves where the closure would result in the interruption of flow downstream from the dam. MM Wildlife-1: A flow by-pass system shall be installed and implemented for any activity that requires closing of a dam s inlet or outlet valves where the closure would result in the interruption of flow downstream from the dam. MM Wildlife-2: Aquatic surveys and temporary exclusionary screens. MM Wildlife-4: Injunction Pesticides Restriction MM General-1: Conduct a project level CEQA review of reservoir dewatering. MM General-2: Consult with CDFG and any other applicable resource agency and obtain all necessary permits. MM General-3: Prepare a reservoir specific dewatering plan. MM Wildlife-1: A flow by-pass system shall be installed and implemented for any activity that requires closing of a dam s inlet or outlet valves where the closure would result in the interruption of flow downstream from the dam. MM Wildlife-3: Conduct compensatory mitigation for take of California tiger salamander, California red-legged frog, foothill yellow legged frog and western pond turtle. MM Wildlife-4: Injunction Pesticides Restriction MM Wildlife-5: Live trapping impact minimization and avoidance measures for non-target species. MM Wildlife-6: Protected species avoidance during burrow removal. MM Wildlife-7: Avoidance and impact minimization measures for impacts to individual California tiger salamanders, California red-legged frogs, foothill yellow-legged frogs or western pond turtles. MM Wildlife-8: Wildlife avoidance during weep hole/expansion joint cleaning and repair. June 2011 Page ES-3

9 Executive Summary Impact Disturbance, injury or mortality of California horned lizard Disturbance, injury or mortality of white-tailed kite, northern harrier, golden eagle, loggerhead shrike, tricolored blackbird and migratory birds Disturbance, injury or mortality of San Francisco dusky-footed woodrat Table ES-1: Significant Project Impacts With Mitigation Measures Mitigation MM Wildlife-9: Horned Lizard Avoidance. MM Wildlife-4: Injunction Pesticides Restriction MM Wildlife-8: Wildlife avoidance during weep hole/expansion joint cleaning and repair. MM Wildlife-10: Disturbance free buffer for avoidance of active migratory bird nests. MM Wildlife-11: Bait stations, when used, shall be of a modified T-tube design. MM Wildlife-4: Injunction Pesticides Restriction MM Wildlife-5: Live trapping impact minimization and avoidance measures for non-target species. MM Wildlife-6: Protected species avoidance during burrow removal. MM Wildlife-8: Wildlife avoidance during weep hole/expansion joint cleaning and repair. MM Wildlife-11: Bait stations, when used, shall be of a modified T-tube design. MM Wildlife-12: San Francisco dusky-footed woodrats, impact avoidance and compensation Disturbance of ringtail MM Wildlife-5: Live trapping impact minimization and avoidance measures for non-target species. MM Wildlife-11: Bait stations, when used, shall be of a modified T-tube design. MM Wildlife-13: Ringtail impact avoidance, habitat mitigation Interfere with the movement of native wildlife species or native wildlife nursery sites Hydrology and Water Quality Degradation water quality with use of pesticides Cessation of flows could have a significant effect on water quality in the stream. Sediments collected from Guadalupe watershed could be contaminated with mercury. MM Wildlife-5: Live trapping impact minimization and avoidance measures for non-target species. MM Wildlife-6: Protected species avoidance during burrow removal. MM Wildlife-11: Bait stations, when used, shall be of a modified T-tube design. MM General-3: Prepare a reservoir specific dewatering plan. MM Water Quality-1: Poison bait containing rodenticides will not be applied to areas inundated by water or distributed when rainfall is forecast in the next 48 hours. Spilled or unconsumed bait will be removed following baiting operations. Dead carcasses of poisoned rodents will be removed daily and disposed of properly. MM Wildlife-4: Injunction Pesticides Restriction MM Wildlife-1: A flow by-pass system shall be installed and implemented for any activity that requires closing of a dam s inlet or outlet valves where the closure would result in the interruption of flow downstream from the dam. MM General-3: Prepare a reservoir specific dewatering plan. MM Hazards-2: Dams located within the Guadalupe River watershed shall have any removed sediments and soils tested for mercury prior to disposal. June 2011 Page ES-4

10 Executive Summary Table ES-1: Significant Project Impacts With Mitigation Measures Impact Mitigation Hazards and Hazardous Materials Expose people or structures to the risk of wildland fires Expose workers or the public to contaminated sediment Hazards associated with shooting of burrowing rodents Danger to the public and domestic pets associated with kill traps Exposure of workers or the public to asbestos during demolition of older structures Cultural Resources Disturbance of unknown cultural resources during ground disturbing activities Damage to paleontological resources from maintenance activities or increased flows associated with dewatering Geology, Soils, and Mineral Resources Soil erosion and loss of topsoil from temporary access roads Bank erosion from increased stream flows associated with reservoir lowering Increase risk of landslide or soil instability from maintenance or geotechnical investigation on steep slopes MM Hazards-1: Fire prevention measures will be implemented to reduce the risk of wildfire MM Hazards-2: Dams located within the Guadalupe River watershed shall have any removed sediments and soils tested for mercury prior to disposal. MM Hazards-3: If shooting is used as a method to control ground squirrels, any trail adjacent to the area of control will be closed to public use for the duration of activity. MM Hazards-4: If kill traps are used as a method to control burrowing rodents they shall be located at least 200 feet from a public trail. MM Hazards-5: The District will follow all BAAQMD regulations pertaining to demolition of structures. MM Cultural-1: If a project entails excavation or disturbance of subsurface sediments in an area identified as medium-high for buried cultural resources, a professional archaeologist shall be consulted as to the best course of action. MM Paleo-1: If paleontological resources are discovered during any activity, all work shall be suspended in the immediate area, or if the resources are in-stream, the site will be isolated from the live stream. MM Geology-1: Temporary access roads shall be recontoured and revegetated immediately after work requiring use of the roads is complete. MM General-3: Prepare a reservoir specific dewatering plan. MM Geology-2: If a road maintenance activity is to be performed that includes cut into an adjacent steep slope (steeper than 2:1), slope stability shall be considered by a geosciences professional. MM Geology-3: Exploratory work proposals shall be reviewed by a qualified engineer or engineering geologist who will determine if the proposed work could cause slope instability. June 2011 Page ES-5

11 Executive Summary Table ES-1: Significant Project Impacts With Mitigation Measures Impact Mitigation Noise Produce noise levels in excess of applicable standards Air Quality Violate regional air quality standards MM Noise-1: Conduct regular noise monitoring during maintenance activities that may create noise levels greater than 75 dba at an adjacent residential property line. Equipment generating noise in excess of the standard will be stopped and the District shall take action to reduce the noise level to less than 75 dba, prior to restarting work MM Noise-2: Equipment that exceeds 85 dba at 25 feet shall not be utilized while conducting DMP activities around the Rinconada and Vasona dams. MM Air Quality-1: Any activity that requires running a diesel generator for 24 hours, must use a generator manufactured since January 1996 that is certified to meet EPA and CARB Tier 1 Emission Standards, and equipped with an exhaust particulate filter system or other emission controls to limit the emission of ROG, NO x and PM 2.5 to 54 pounds per day and PM 10 to 82 pounds per day. Traffic and Transportation Block access to MM Traffic-1: Prior to staging and access of equipment at Lexington Quarry Lenihan Dam that could impede trucks from accessing Lexington along Alma Bridge Quarry via Alma Bridge Road, the District would consult with the Road quarry s operations manager or equivalent personnel to establish Obstruct emergency access on public roads Recreation Reduce the availability of water-based recreational activities from reservoir dewatering Aesthetics Degrade the visual character of the project area Damage or destroy scenic rock outcroppings specific measures to ensure vehicular access for quarry vehicles. MM Traffic-2: Prior to commencing any activities that could block a roadway the District will ensure that emergency access is accommodated through all phases of the activity. MM General-3: Prepare a reservoir specific dewatering plan. MM Geology-1: Temporary access roads shall be recontoured and revegetated immediately after work requiring use of the roads is complete. MM Aesthetics-1: Fencing shall be designed to blend in with the color and contour of the natural landscape. MM Aesthetics-2: No work shall be performed at Almaden Dam that would permanently damage or destroy rock outcroppings. June 2011 Page ES-6

12 Executive Summary Table ES-1: Significant Project Impacts With Mitigation Measures Impact Disturb adjacent property owners with new source of light if night work is necessary Cumulative Impacts Contribution to regional air quality concerns Mitigation MM Aesthetics-3: If temporary lighting is necessary measures such as directing lighting downward and away from residences, reducing bulb wattage to the minimum required, and utilizing shrouds shall be implemented. MM Cumulative-1: Implement Construction Emissions Control Technology SIGNIFICANT AND UNAVOIDABLE IMPACTS The following impacts are identified as significant and unavoidable. Impacts from noise if construction or a generator is required at night. Most maintenance will be conducted during regular construction hours. However, there is the potential for some work, such as inlet/outlet repairs, or running a generator to provide flow bypass, to require work through the night. Construction work at night, or the use of a generator may generate noise at levels that exceed the noise standards of the local jurisdiction. Such an impact would be significant and unavoidable. Impacts to recreational opportunities if Anderson Reservoir is dewatered. The District would attempt to minimize the negative impacts of reservoir dewatering on recreation through implementation of mitigation measures requiring the development a dam-specific reservoir dewatering plan. However, significant recreational impacts may occur if Anderson Reservoir, which is widely used by the public, is unavailable for water-based recreational pursuits for the duration of dewatering. Dewatering Anderson Reservoir may cause overuse of other local reservoirs, or force people to travel much greater distances for similar recreational opportunities, both of which could result in significant impacts. In addition, the following impacts are potentially significant and unavoidable subject to future project-level review: Impacts to sensitive plants, vegetation communities, and sensitive wildlife species downstream of reservoirs from the dewatering. Proposed mitigation measures to conduct environmental review prior to dewatering a reservoir, obtaining regulatory permits prior to dewatering, preparing a reservoir specific dewatering plan, and compensation for the loss of sensitive habitats or plant populations would likely mitigate any potential impact, but because the effects of dewatering are addressed programmatically it is not known if the proposed mitigation measures will reduce all potential effects to a level of less than significant. Accordingly, dewatering has potentially significant and unavoidable impacts on special status plants and sensitive natural communities. Further review will be necessary to determine if all potential impacts have been addressed and whether impacts are avoidable with feasible mitigation. June 2011 Page ES-7

13 Executive Summary Cumulative impacts to sensitive habitats, vegetation, and wildlife from dewatering as discussed above. ALTERNATIVES TO THE PROPOSED PROJECT CEQA requires that an EIR evaluate a reasonable range of alternatives to a proposed project. An EIR is not required to consider every conceivable alternative to a project; consideration should focus on alternatives that appear to be feasible, would meet the project objectives, and would avoid or substantially lessen at least one of the project s significant environmental effects. Alternatives are limited for the DMP since many of the activities are required to ensure the structural integrity and safety of the dams. Maintenance of the dams is based on dam safety requirements outlined by the DSOD and FERC. Maintenance cannot be performed at a different location because the work must address maintenance issues at each dam s specific location. The type of maintenance that must be performed is also fixed based on the engineering of the dams and the existing equipment. This EIR analyzes one alternative to the DMP as proposed, a No Pesticide alternative, in addition to the No Project alternative. As discussed in Chapter 6, the No Project alternative would maintain the District s current practice with case-by-case maintenance and environmental review, with similar potentially significant environmental effects than the proposed project. However, this alternative does not account for cumulative impacts from dam maintenance activities as well as the proposed project would. The No Pesticides Alternative would be marginally environmentally superior to the proposed Project but would not reduce any significant effects to less than significant levels and would be less effective in rodent control. This alternative, however, would be much more costly and require the use of greater resources and personnel, in part, because trapping is much less effective than baiting for rodent control. The alternative could result in less effective dam maintenance. If rodents are not controlled effectively, burrows could compromise the dams or portions of the dams and the District may have difficulty in meeting its requirements for dam maintenance under DSOD. Chapter 6 also discusses three alternatives that were considered, but determined to be infeasible: Dam Decommissioning: Dam surface hardening; and No Action Alternative (No Maintenance). PUBLIC AND AGENCY CONCERNS AND AREAS OF KNOWN CONTROVERSY The District s use of pesticides in its maintenance activities has generated concern from the pubic and resource agencies. There are concerns about impacts to the environment and sensitive species from the use of herbicides for vegetation management and environmental and animal welfare concerns from rodenticide use for controlling burrowing rodents. June 2011 Page ES-8

14 Executive Summary ISSUES TO BE RESOLVED The District has included reservoir drawdown in the PEIR since some activities defined in the DMP may require reservoir drawdown. Since reservoir drawdown is an anticipated result of DMP activities it is included to provide as complete a summary of the potential environmental effects of the DMP as possible. However, the impacts associated with reservoir drawdown will depend on features of the particular reservoir, water level in the reservoir at the time, and potential methods to provide downstream flows while the reservoir is out of commission. These factors are not known at this time, so the discussion in the PEIR is at a necessarily broad level. When reservoir drawdown is necessary for maintenance of a particular dam, the District will study the impacts associated with the specific set of circumstances and review those impacts against impacts discussed in this DMP. If all impacts are covered in the PEIR, then the drawdown could proceed. Otherwise, the District would be required to conduct supplemental environmental review under CEQA. June 2011 Page ES-9

15 CHAPTER 1. INTRODUCTION This document is the draft Program Environmental Impact Report (PEIR) analyzing the environmental effects of the s proposed Dam Maintenance Program (DMP). This EIR has been prepared in compliance with the California Environmental Quality Act (CEQA) to provide an objective analysis to be used by the Santa Clara Valley Water District, as the Lead Agency, as well as other agencies and the public, in their considerations regarding the implementation, rejection, or modification of the DMP as proposed. The EIR itself does not determine whether the DMP will be implemented or not; it only serves as an informational document in the decision-making process. Following public review of this document, the District s Board of Directors will use the information it contains, together with comments submitted by other agencies and the public during the review period, to evaluate if and how the DMP should proceed. Resource agencies such as the U.S. Army Corps of Engineers, California Department of Fish and Game, Regional Water Quality Control Boards, NMFS, and USFWS will use this analysis in assessing whether to grant permits necessary for the DMP to proceed PROGRAM OVERVIEW The (SCVWD or District) owns 14 regulated water retention facilities that are operated under licenses granted by the State of California Department of Water Resources, Division of Safety of Dams (DSOD). Twelve of these facilities include earthen dams with regulated reservoirs, one is an earthen dam with a covered reservoir at a water treatment plant, and one is an in-stream retention facility to enhance groundwater recharge (Refer to Figure in Chapter 2). The District maintains these dam facilities to ensure public safety and adequate system functionality, and to ensure safe and reliable reservoir operation and water delivery. A number of different maintenance activities must be performed on the dam facilities, both on a defined schedule as preventative maintenance and on an as-needed basis as corrective maintenance. The District prepared the DMP to identify these maintenance activities. The DMP is a process and policy document that will be used to guide implementation of dam maintenance activities and projects. The DMP outlines specific measures, protocols, policies, and reporting requirements to ensure that all routine dam maintenance activities would be implemented in an efficient and environmentally sensitive manner. Maintenance activities are undertaken for a variety of reasons, including: District mandate to provide a reliable, clean water supply for current and future generations (District Ends Policy 2 [as of November 23, 2010]); DSOD requirements to maintain dam facilities; Changes to facilities that may arise from geological processes (fault movement, landslides, etc); Aging infrastructure needs; and Federal Energy Regulatory Commission (FERC) requirements at Anderson Dam. June 2011 Page 1-1

16 Section 1.1 Program Overview CHAPTER 1 The District has been conducting maintenance as necessary on the dams by reviewing each activity separately, or through review of subsets of maintenance activities discussed in this DMP. For example, the District approved a set of maintenance activities with minimal environmental impact in 2004, which was updated in 2010, to allow some dam maintenance activities to be carried out with implementation of best management practices (BMPs). The District evaluated the use of rodenticides and other rodent control measures at dam facilities, and adopted a Mitigated Negative Declaration in 2007; in 2009 the District updated this MND and expanded the scope to include burrow removal in the Rodent Control and Burrow Removal on 14 Dams MND. The two projects described above that underwent separate CEQA review have helped to ease some maintenance needs, but the District is still in need of a comprehensive program that will streamline the environmental process for routine maintenance activities and allow the activities to be performed in an effective and timely manner. June 2011 Page 1-2

17 Section 1.2 DMP Program Objectives CHAPTER DMP PROGRAM OBJECTIVES The DMP objectives are to: Maintain the safety and utility of the dams, dam appurtenances, and equipment structures; Coordinate the various aspects of dam maintenance integrating environmental compliance; Streamline environmental review to allow activities to be performed in a timely and cost-effective manner; and Provide consistency in implementation and oversight of dam maintenance activities. The purpose of the DMP is to provide a comprehensive approach for dam maintenance to allow the District to ensure the reliability and safety of the District dams and reservoirs for the residents of Santa Clara County and to conduct maintenance activities in an environmentally responsible and cost-effective manner. The protocols for maintenance are identified in the DMP based mainly on existing procedures. The DMP identifies changes in short-term practices or long-term strategies that would be beneficial to the District through reduction of maintenance costs and protection of environmental resources. All maintenance activities and the environmental protection measures to be applied to the maintenance program are described in the DMP. June 2011 Page 1-3

18 Section 1.3 California Environmental Quality Act (CEQA) Process CHAPTER CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) PROCESS OVERVIEW Maintenance activities have previously been subject to case-by-case determination of the potential for environmental impacts and the appropriate review under CEQA. Usually, individual maintenance projects have been determined to be categorically exempt 1 or are conducted after issuing a Mitigated Negative Declaration (MND) and finding that all environmental effects were less than significant. Several of the individual maintenance activities included in the DMP would still qualify for an exemption under CEQA; however, the public and environment are better served in examining the total and cumulative impacts associated with dam maintenance in a comprehensive manner under the proposed program. The District has prepared this PEIR under CEQA to evaluate the environmental effects of the DMP. The District is the CEQA lead agency. Some of the activities defined in the DMP result in potentially significant effects on the environment. The PEIR is used to identify these potentially significant impacts and to describe measures to avoid, reduce, or mitigate for them where feasible. The PEIR will also be used by several state and federal regulatory agencies in evaluating the District s applications for long-term permits to perform maintenance on dam facilities CEQA DEFINITION OF PEIR According to CEQA Guidelines Section 15168, a PEIR is an Environmental Impact Report (EIR) that may be prepared for a series of actions that can be characterized as one large project and are related either: Geographically; As logical parts in the chain of contemplated actions; In connection with issuance of rules, regulations, plans, or other general criteria to govern the conduct of a continuing program; or As individual activities carried out under the same authorizing statutory or regulatory authority and having generally similar environmental effects, which can be mitigated in similar ways. 1 Section of the CEQA Guidelines state that the only activities that are exempt from CEQA review are the following (1) Activities that are not projects; (2) Projects that have been granted exemption by statute or by categorical exemption; or (3) Activities covered by the general rule that CEQA applies only to projects which have the potential for causing a significant effect on the environment, where it can be seen with certainty that there is no possibility that the activity in question may have a significant effect on the environment. June 2011 Page 1-4

19 Section 1.3 California Environmental Quality Act (CEQA) Process CHAPTER REASONS FOR PREPARING A PEIR The District is preparing this PEIR to: Ensure consideration of cumulative impacts that might not be identified in a case-by-case analysis of individual maintenance activities; Avoid duplicative review of basic policy considerations; Allow the District to consider broad policy alternatives and program-wide mitigation measures at an early time when the agency has greater flexibility to deal with basic issues or cumulative impacts; and Allow reduction in paperwork APPLICABILITY OF A PROGRAM EIR A PEIR approach was determined as best suited for the DMP project. According to CEQA Guidelines Section 15168, a PEIR enables the District to characterize the overall program as the project being approved. The PEIR analyzes the program as a whole, including all of its constituent activities. When a later activity is determined by the lead agency to be within the scope of a PEIR, no new environmental document is required unless changes in the project, changed circumstances, or significant new information indicate that the later activity would have a new or more severe environmental impact relative to the impacts identified in the PEIR (CEQA Guidelines Sections and 15162). For later activities that are not within the scope of the PEIR, additional environmental review may be required to implement individual program components or activities. The intent of this PEIR is to adequately capture the impacts of the DMP such that future CEQA documentation is not necessary. However, it is possible that changes to the DMP, changed circumstances or significant new information pertaining to specific aspects of implementation of the DMP, could result in new, different, or more significant impacts than have been disclosed. Such impacts would be evaluated in a subsequent environmental document. The DMP currently addresses maintenance at 14 identified facilities. If the District were to acquire a new dam in the future, it could be included in the DMP, but only after completing additional environmental review DISTRICT USE OF THE DMP AND PEIR The District intends to adopt the DMP as a permanent program, making modifications and creating updates as needed. The District will use this PEIR to consider the DMP s environmental effects, feasible alternatives and mitigation measures to address those effects found to be significant, and in consideration of whether to adopt the DMP. If the DMP is approved, the District will prepare Annual Maintenance Plans, and conduct focused reviews, including determinations of project coverage within the PEIR. June 2011 Page 1-5

20 Section 1.4 Regulatory Use of the PEIR and Permits CHAPTER REGULATORY USE OF THE PEIR AND PERMITS Should the DMP be adopted, the District will apply for long term regulatory permits. Regulatory agencies will consider the information contained in the DMP and PEIR in issuing permits. When it is time to renew permits, the District will need to comply with applicable regulations at that time, including CEQA, as appropriate. The proposed program would require the approval of permits by a number of public agencies, as listed in Table Table 1.4-1: Permits and Approvals Necessary for Dam Maintenance Activities Permit or Approval Purpose Regulatory Agency Federal Clean Water Act Section 404 Permit and 401 Certification Endangered Species Act (ESA) Consultation under Section 7 or coverage under an Habitat Conservation Plan (HCP), under Section 10 State Lake or Streambed Alteration Agreement Storm Water Pollution Prevention Plan (SWPPP); enrollment under General Construction National Pollution Discharge Elimination System (NPDES) Permit National Pollutant Discharge Elimination Program Permit Local Encroachment Permit SOURCE: RMT 2010 For any activity that could involve or require discharge of dredged and fill material into Waters of the US. For potential impacts to federally threatened or endangered species from any activity. For any activity that could alter a streambed or stream flow. For any activity that requires grading or ground disturbance of more than 1 acre (such as a road reconstruction). For flow by-pass releases. For any work that could block or impede a city or county-owned road. U.S. Army Corps of Engineers (USACOE) US Fish and Wildlife Service (USFWS) and the National Marine Fisheries Service (NMFS) California Department of Fish and Game (CDFG) San Francisco Bay Area Regional Water Quality Control Board (RWQCB) Monterey Bay Area RWQCB (for Chesbro and Uvas only) San Francisco Bay Area RWQCB Monterey Bay Area RWQCB (for Chesbro and Uvas only) Santa Clara County Department of Public Works June 2011 Page 1-6

21 Section 1.5 Public Involvement CHAPTER PUBLIC INVOLVEMENT NOTICE OF PREPARATION A Notice of Preparation (NOP) was published in the San Jose Mercury News and mailed to various agencies and interested community members on February 9, Environmental parameters identified in the NOP as being potentially affected by the proposed project included: Air Quality Biological Resources Cultural Resources Geology/Soils Hazards and Hazardous Materials Hydrology and Water Quality Land Use, Planning and Recreation Noise Public Services Transportation/Traffic Utilities and Service Systems An informational meeting was held on February 28, 2007 to describe the proposed project and the environmental review process, and to receive input from the community to help refine the scope of issues and alternatives to be addressed in the Draft PEIR. Comments on the NOP were received from Santa Clara County Parks and Recreation, San Francisco Bay Region RWQCB, CDFG and DSOD. The NOP and comment letters are included in Appendix I PUBLIC AND AGENCY REVIEW OF DRAFT EIR Once a draft EIR is ready, the lead agency must notify agencies and the public that it is available for review. The official notification, referred to as a Notice of Completion (NOC), is sent to the State Clearinghouse, County Clerk s office for posting, and to any other parties who have requested it. The NOC must be published in a general circulation newspaper. Issuance of the NOC initiates a public review period during which the lead agency receives public and agency comments on the proposed project and the document. The purpose of public circulation is to provide agencies and interested individuals with opportunities to comment on or express concerns regarding the contents of the draft EIR. Copies of the draft PEIR will be provided to interested agencies and the public. The PEIR and all technical documents used in preparation of the analysis are available at the following location: 5750 Almaden Expressway San Jose, CA June 2011 Page 1-7

22 Section 1.5 Public Involvement CHAPTER 1 Comments regarding this draft EIR can be submitted within the review time to: Scott Akin 5750 Almaden Expressway San Jose, CA sakin@valleywater.org PREPARATION OF FINAL EIR Following public review of this Draft PEIR, the District will collate all the comments received and provide a response to each comment. A Final PEIR will be prepared that includes any changes made to the Draft PEIR based on comments received with a list of all individuals, organizations, and agencies that provided comments and a copy of their comments. The District s Board of Directors will use the information contained in the Final PEIR, together with any other comments submitted by other agencies and the public, to evaluate how and if the DMP should proceed. June 2011 Page 1-8

23 Section 1.6 Public and Agency Concerns and Areas of Known Controversy CHAPTER PUBLIC AND AGENCY CONCERNS AND AREAS OF KNOWN CONTROVERSY The District s use of pesticides in its maintenance activities has generated concern from the pubic and agencies. There are concerns about impacts to the environment and sensitive species from the use of herbicides for vegetation management and environmental and animal welfare concerns from rodenticide use for controlling burrowing animals. June 2011 Page 1-9

24 Section 1.7 Issues to be Resolved CHAPTER ISSUES TO BE RESOLVED The District has decided to include reservoir drawdown in the PEIR since some activities defined in the DMP may require reservoir drawdown. Since reservoir drawdown is an anticipated result of DMP activities, it is included to provide as complete a summary of the potential environmental effects of the DMP as possible. However, the impacts associated with reservoir drawdown will depend on features of the particular reservoir, water level in the reservoir at the time, and potential methods to provide downstream flows while the reservoir is out of commission. These factors are not known at this time, so the discussion in the PEIR is at a necessarily broad level. When reservoir drawdown is necessary for maintenance of a particular dam, the District will study the impacts associated with the specific set of circumstances and review those impacts against impacts discussed in this DMP. If all impacts are covered in the PEIR, then the drawdown could proceed. Otherwise, the District would be required to conduct supplemental environmental review under CEQA. June 2011 Page 1-10

25 Section 1.8 Topics Not Covered in Detail in This EIR CHAPTER TOPICS NOT COVERED IN DETAIL IN THIS EIR The following topics included in the Initial Study Checklist have been omitted from detailed analysis in this PEIR because they involve resources that would not be affected by the proposed project. AGRICULTURAL RESOURCES The District s dams are man-made features and do not support any agricultural uses. The areas in which the dams are located are designated as Regional Park, Open Space, or Residential. It is possible that mitigation associated with amphibians could take place on land currently grazed. If so, this land would be upland habitat offering rodent burrows for amphibian refuge. The grazing activity would be compatible with the mitigation, and in fact, necessary to reduce grass and forb cover, that if otherwise left ungrazed, would preclude rodents that maintain the burrows used for amphibian refuge. Mitigation associated with plants would occur on serpentine soils, and in riparian corridors, woodlands, or wetlands which are not conducive to agriculture. Thus, the project would not convert any prime farmland, unique farmland, or farmland of statewide importance to non-agricultural uses. LAND USE AND PLANNING The DMP would not affect existing land use plans or zoning ordinances within the jurisdictions the dams are located in because activities would not change existing land use. The project would not physically divide a community. The project activities are restricted to the crest and face and immediate vicinity of existing dams and their appurtenant structures and would not include activities that would cause installation of structures, removal of structures, or any other permanent activity that could physically divide a community. Where a local jurisdiction may have policies that relate to specific resource categories such as noise and traffic, those policies, and the DMP s compliance, are discussed in the appropriate resource chapter. POPULATION AND HOUSING The project would not induce population growth in the area. The project involves maintenance of existing dam structures and would not include expanding water infrastructure systems. The project would not displace housing, necessitate the construction of replacement housing elsewhere or displace people. All proposed activities occur at existing facilities that do not include housing. PUBLIC SERVICES Project activities are focused on maintenance of dam and appurtenant structures. None of the activities would result in the generation of additional demand for public services (by way of additional, unexpected development) or in the need for new or alteration of existing governmental facilities. Work could temporarily affect park and trail usage around the reservoirs, but these effects would be temporary and maintenance shutdowns would be coordinated with the parks, see Section 3.11, Recreation. The project would not have an effect on public services. June 2011 Page 1-11

26 CHAPTER 2. PROJECT DESCRIPTION 2.1. INTRODUCTION INTRODUCTION The proposed project is the District s adoption and implementation of the DMP. The DMP outlines specific measures, protocols, policies, and reporting requirements to ensure that dam maintenance activities are implemented in an efficient and environmentally sensitive manner. The DMP is provided with this PEIR on compact disc (CD). The project description is the DMP, incorporated by reference, and is summarized in this chapter PROJECT LOCATION AND SETTING The project area addressed in the DMP lies entirely within Santa Clara County, with many of the facilities located in eastern and western foothill and mountainous areas of the County. The dams included in the DMP include: Almaden Dam Anderson Dam Calero Main Dam Calero Auxiliary Dam Calero Fellows Dike Chesbro Dam Coyote Dam Coyote Percolation Pond Dam Guadalupe Dam Lenihan Dam Stevens Creek Dam Rinconada Treated Water Reservoir Dam Uvas Dam Vasona Dam The DMP work area includes the dams, all appurtenant structures, and associated District-maintained access roads. The work area includes a buffer of 100 feet from any dam road or structure, up to the District s property line. The locations of dam facilities are shown on maps in Appendix VII. Within the area of potential effect (APE), an area of routine maintenance effects (ARME) has also been identified. These are the areas where activities will occur on a regular basis. The ARME includes areas of routine work and a corresponding buffer defined by District engineers and maintenance personnel. Routine maintenance includes activities such as road repair, bank stabilization at the base of the spillways, rodent control, and equipment maintenance, which could happen every year or every few years. Approximately 85 percent of impacts would occur within the ARME. Some less frequent impacts could occur outside the ARME but within the larger APE. These impacts are estimated to be about 15 percent of the total impacts from the program. June 2011 Page 2-1

27 Figure 2.1-1: SCVWD Dam Locations June 2011 Page 2-2

28 Section 2.2 Maintenance Activities CHAPTER MAINTENANCE ACTIVITIES MAINTENANCE ACTIVITIES MASTER LIST The Dam Maintenance Activity Master List is included in Appendix VIII of the DMP. The master list was compiled based on historic records and accounts of dam maintenance, the DSOD, FERC, other regulatory needs, dam and appurtenant structure standards for operation, instrumentation and safety, and other manufacturers recommendations for serviceable parts associated with the dams. The master list describes the facility where the maintenance takes place and asset or activity. The master list of activities serves as the basis for the activities defined in the DMP MAINTENANCE CATEGORY DESCRIPTIONS Overview The DMP covers activities related to maintenance of 14 dams and their ancillary structures. The dam systems and facilities covered in the DMP are described below. The DMP includes over 65 activities, which are grouped into four major categories that are performed as either routine or corrective maintenance. Routine (preventative) maintenance can be described as normal work performed to existing equipment to maintain its life cycle or keep it in acceptable condition. Corrective maintenance can be described as the replacement of components or appurtenances that have failed, or as unplanned work. The activities included in the DMP also address the requirements of FERC for maintenance of the Anderson Dam facilities. Chapter 2 of the DMP includes a complete description of the dam maintenance activities at each dam. Some maintenance activities would also require drawing down the water levels in the reservoirs to access the equipment and appurtenant structures. Reservoir dewatering is addressed in the DMP and this PEIR. Maintenance activities are divided into four main categories, which are subdivided into 14 sub-activities, as described below: 1. Surfaces and/or Earthwork: Vegetation management Burrowing rodent control Access road and boat ramp work Erosion Control/erosion repair/bank stabilization/drainage Embankment repair (cracking and slumping) Trash and debris removal 2. Maintenance of Dam Appurtenances and Equipment: Any work on dam equipment, mechanical equipment, electrical, monitoring instruments, or supervisory control and data acquisition systems (SCADA) Inlet/outlet work, including outlet pipes and tunnels Valve systems and hydraulic systems June 2011 Page 2-3

29 Section 2.2 Maintenance Activities CHAPTER 2 Sediment removal around intake structures and hydraulic lines Concrete structure repairs, replacement and cleaning (including weep holes and expansion joints) Seepage monitoring systems (weirs and piping) Other appurtenances (piezometers, electrical systems, fences, etc.) 3. Inspections, Monitoring, and Exploratory Work Exploratory field investigations (including exploratory drilling on land or from barges in the reservoirs) DSOD and other inspections and survey work 4. Dewatering to undertake refurbishment of the dam appurtenances or interior basin dam surfaces (exclusive of dam reconstruction) Surfaces Work VEGETATION MANAGEMENT Dam facilities require vegetation control in order to maintain the integrity of the dam surface and to visually inspect the dam. Vegetation must be removed from cracks in concrete, from within weep holes and expansion joints, on dam faces and spillways, and roads. Vegetation must be cleared from where the dam contacts native materials (abutments). Young trees must be removed before they become established. Trees that have become established on dam faces must be removed to ensure visibility of dam surfaces, and to ensure dam integrity. No woody growth is permitted on the dam face; grass is the only vegetation allowed by DSOD regulations. Vegetation management would involve the combination of herbicide application, mechanical methods, manual removal methods, grazing, and potentially prescribed burning if it is allowed in the future. VEGETATION MANAGEMENT METHODS Overview of Methods A combination of vegetation management methods are used in the DMP due to varying site characteristics. Herbicide use is the preferred method of vegetation management where it would not have the potential to affect special status and other non-target species. Table lists the various methods of vegetation management; the time of year that each method should be employed, the efficacy of the method, the cost of the materials, and the labor requirements. June 2011 Page 2-4

30 Section 2.2 Maintenance Activities CHAPTER 2 Table 2.2-1: Proposed Vegetation Management Methods Control Method Time of Year Efficacy Cost of Materials Labor Herbicides Winter, Spring, Fall High Medium Medium Mechanical Removal Summer, Fall High Low High Hand Removal Spring, Summer, Fall Medium Low High Grazing Spring, Summer, Fall Medium Low Low Prescribed Burning Spring High Low High Herbicide Use Herbicide use by the District is restricted to those types that have been approved at the federal and state level. Table identifies the herbicides used by the District, their application rates, and those herbicides that are restricted by the U.S. Environmental Protection Agency (US EPA 2 ). The use of a new herbicide would be evaluated using the following policies before the District would formally accept them into use under the DMP: Products listed on the state Department of Pesticide Regulation (DPR) A list of known groundwater contaminants are not used (Atrazine, Simazine, Bromacil, Diuron, Prometon, Bentazon, and Norflurazon); Federal and state recommendations and regulations are followed for herbicide selection and application; The Control of Oversight of Pesticide Use (District ISO procedure Q751D02) specifies the process the District uses to evaluate pest control methods, and alternatives to pesticides. 2 The Center for Biological Diversity (CBD) reached settlement agreements with the US EPA to protect twelve threatened or endangered species from 104 pesticides currently authorized for use in California. The first settlement was reached on October 17, 2006 (US EPA 2009a) for the California red-legged frog, the second on May 17, 2010 covering 11 additional species and their habitat in the Greater San Francisco Bay Area Counties. The agreements are a result of lawsuits filed by CBD against the US EPA in 2002 and The agreements approved by a U.S. District Court, prohibits by injunction, EPA licensed use of these pesticides in and adjacent to core habitats for the California red-legged frog throughout California, and for 11 additional species in the Greater SF Bay Area, except for limited circumstances until the US EPA completes formal consultations with the USFWS to ensure the chemicals are not jeopardizing or contributing to the decline of the species. The settlement terms stipulate that review and consultations are to occur on a schedule intending to be completed by June 2011 Page 2-5

31 Section 2.2 Maintenance Activities CHAPTER 2 Table 2.2-2: Application Rate for Herbicides Used by the District Application Rates Active Ingredient Herbicide Product % Active Ingredient Pounds/Acre Acid Equivalent (ae) mg/m 2 Spray Dilution % Solution g/l On US EPA Injunction List? isoxaben Gallery No dithiopyr Dimension Ultra No triclopyr Garlon 3A Yes triclopyr Garlon Yes imazapyr Habitat/ Polaris Yes pendimethalin Pendulum Aqua Cap Yes glyphosate Aquamaster Yes glyphosate RoundUp Pro Yes oryzalin Surflan Yes clopyralid Transline % No Target Pro Spreader Used with 0.5% Aqua-master Garlon Surfactant R-11 surfactant Used with Aqua-master Garlon Surfactant Notes: mg/m 2 = milligrams per square meter g/l = grams per liter SOURCE: SCVWD, VEGETATION MANAGEMENT, 2011 Herbicides will be applied in the following areas: 0.25% Yes 0.5% 0.25% Yes Downstream dam faces: Selective pre- and post-emergent herbicides 3 may be used to target undesirable vegetation present on dam faces or prevent the emergence of undesirable vegetation. Herbicides would be used to specifically control broad-leafed and woody vegetation on the downstream faces of dams. Selective herbicides would not target grasses, as the establishment of grasses is important to control erosion on dam faces. Unlike broadleaf plants, grass cover does not interfere with inspections of downstream dam faces for seepage and other surface distress, which may indicate a significant problem with the dam facility. Broadleaf plants and woody vegetation can also damage the earthen structure of the dam as they die and fall over and/or decay. Upstream dam faces: The upstream face of the dam is the portion of the dam sloping from the crest of the dam into the reservoir. Only post-emergent herbicides and surfactants 4 registered for aquatic use will be applied to upstream dam faces. These herbicides will also contain no chemicals 3 Pre-emergent herbicides prevent unwanted vegetation from starting to grow. Post-emergent herbicides are used to kill vegetation that is already growing. 4 A surfactant is a material that is used in some applications to increase the effectiveness of a herbicide. Surfactants are most often used to help a herbicides spread over a leaf surface and penetrate the plant. June 2011 Page 2-6

32 Section 2.2 Maintenance Activities CHAPTER 2 identified on the US EPA s list of restricted herbicides due to the presence of nearby aquatic habitat. Concrete linings: Aquatic herbicides are used to control all vegetation with selected post-emergent herbicides. Broadleaf plants and grasses are controlled with post-emergent herbicides. Roadways: Maintenance roads, including drainage facilities and buffer strips between the roads and the drainage strips, may be kept free of weeds and grasses with pre- and post-emergent herbicides. Only aquatic registered herbicides and surfactants are allowed for use within 20 feet of a water body. Mechanical Vegetation Removal The District uses mechanical equipment in conjunction with or in place of chemical methods to control vegetation. Mechanical methods may be used in areas where sensitive plant or animal species that could be harmed by specific herbicides may be found. Flail mowing is a mechanical method to cut large areas of vegetation and grass. Areas could be mowed up to three times between the period of May and October. Mowing is performed on dam faces and at dam facilities such as blockhouses and fences where herbicides cannot be applied. Overhanging growth is removed using mechanical or hand removal methods. Overhanging growth, which impedes access roads to dam facilities, is pruned back annually to allow a minimum of 14 feet of vertical clearance and 2 feet of horizontal clearance from the road surface so that the largest maintenance vehicles can enter the project areas unrestricted. Overhanging growth and vegetation would also be trimmed back at least 1 foot behind any roadside drainage swales to allow maintenance of road drainage. Hand Vegetation Removal Hand vegetation removal is utilized in areas where mechanical equipment cannot enter, such as in wetland areas, or around the dam outlets, and to trim trees that may be blocking roadways and access routes. Woody vegetation in these areas is cut using handsaws, chainsaws, and other hand-operated tools. The vegetation is loaded into a compactor and hauled to a landfill. Weeds can also be pulled by hand and disposed of offsite. Large vegetation, such as trees, that are removed by mechanical and hand removal methods are given a cut-stump herbicide, which is applied to the surface of the remaining tree stump to prevent June 2011 Page 2-7

33 Section 2.2 Maintenance Activities CHAPTER 2 regrowth of the tree. The cambium layer exposed in the tree stump is treated with a layer of 50 to 100 percent solution of glyphosate. One treatment usually works to prevent re-sprouting; however, a follow-up application may be necessary. All herbicide rules described above apply to this application. Trees that must be removed from the face of dams to comply with DSOD regulations will have the stump and roots dug up and removed to ensure the structural stability of the dam. The surface would then be restored and compacted. Grazing The District may choose to use grazing as a method of vegetation control on the dam faces and surrounding areas. Grazing is considered a means of biological vegetation control. Grazing uses two approaches for placing the undesirable plant(s) at a competitive disadvantage: Grazing is implemented at the time and frequency when the undesirable plant(s) is most vulnerable The grazing behavior and/or the animals used are chosen to specifically target the undesirable plant(s) A grazing plan would be prepared by the District s Vegetation Management Unit (VMU) with input by professionals with experience in using livestock for vegetation management. The VMU would be responsible for implementing the plan. A successful grazing program would beneficially remove the target plants, limit damage to the surrounding non-target vegetation, limit erosion damage to the dam, and integrate efficiently with other control methods being implemented as part of the overall vegetation control strategy. Animals would be herded over the dam face to problem areas and herded away as they graze the target species, such as woody vegetation and invasive species. The animals would be moved to prevent over-grazing that could cause erosion or denudation of the dam face. Livestock would be procured from a contractor specializing in the use of animals for vegetation management. The contractor would provide oversight of grazing, which may include maintenance of the livestock, temporary fencing, shepherding of livestock, and monitoring the extent of damage to target and non-target vegetation. Prescribed Burning Open burning is generally prohibited by Bay Area Air Quality Management District (BAAQMD) under Regulation 5; however, there are exemptions to Regulation 5, which allow fires on June 2011 Page 2-8

34 Section 2.2 Maintenance Activities CHAPTER 2 permissive burn days at certain times of the year. Burning woody debris at the reservoirs would be permissible under Section (BAAQMD 2010a); however, the Santa Clara County Fire Department does not currently allow burning except for agricultural uses because of the high fire hazard risk (Haas pers. comm. 2009). Should burning be allowed in the future, any planned burns would require permission from both the BAAQMD and the Santa Clara County Fire Department. To the extent permitted in the future, the potential impacts from controlled burning are addressed in this PEIR. Prescribed burning utilizes fire to manage vegetation growth, density, and composition. This method of vegetation control is most commonly used for fire suppression but can be an effective method of restoring native species to areas infested with invasive weeds. Prescribed burning works by burning off existing vegetation in a controlled manner. The burn must be properly planned in terms of timing, equipment, and personnel. Firebreaks would be created prior to the burn that are a minimum of 8 to 15 feet wide and border the entire burn area. The fire is ignited along a firebreak, such as a road, plow line, stream or other barrier, and allowed to burn into the wind. Neighbors, the fire department, and law enforcement officials would be notified. Precautions would be taken to ensure that no smoke would flow over roads, trails, or in flight paths. Prescribed burns can only be performed when wind speed, wind direction, cloud cover, relative humidity, and temperature are appropriate. Wind speed and direction are crucial to fire behavior. Wind speeds of 5 to 15 mph, steady from a desirable direction, are preferred. Cloud cover plays a significant role in prescribed burning. As a rule, as cloud cover increases, it becomes more difficult to ignite and maintain a burn (Ohlenbusch and Kunkel 1996). Controlled burns would not occur when cloud cover is greater than 70 percent or clouds are located less than 2,000 feet above the ground. Only trained and experienced personnel would be used to operate tractors and other vehicles. Equipment operators remain in communication with other personnel throughout the burn. BURROWING RODENT CONTROL OVERVIEW OF BURROWING RODENT CONTROL METHODS Burrowing animals present a risk to the structural integrity of the dams. Dams should ideally be rodent-free so that burrows do not threaten the integrity of the dams. Methods for rodent elimination include physical, mechanical, and chemical means of control. After rodent elimination, burrows would be destroyed to prevent the return of rodent populations. Burrow destruction involves excavation, recompaction, and/or grouting holes. Track walking, June 2011 Page 2-9

35 Section 2.2 Maintenance Activities CHAPTER 2 which involves using a track machine with sufficient ground pressure to collapse burrows may be used to destroy burrowing and compact the surface. A combination of burrowing rodent control methods would be used in implementing the DMP. The method selected would depend on the site characteristics and the type of rodents (i.e., ground squirrels, gophers, moles, and/or voles) targeted. Burrow destruction would occur in all instances after burrowing rodents are removed. The District would consider the following control methods and their chemical or physical applications to remove burrowing rodents: Poison bait rodenticides Anticoagulants Strychnine Zinc Phosphide Fumigant rodenticides Gas Cartridge Aluminum Phosphide Trapping Live Catch Traps Kill Traps Shooting Exclusion Gates Table lists the various methods of burrowing rodent control, the time of year that each method should be employed, the efficacy of the method, the cost of the materials, and the labor requirements. Table 2.23: Proposed Burrowing Rodent Control Methods Control Method Time of Year Efficacy Cost of Materials Labor Poison Bait 1 Spring, Fall High Low Low Fumigants Spring High Medium High Trapping Spring, Summer, Fall, Winter Medium High High Shooting Spring, Summer, Fall, Winter Low Medium High Exclusion Gates Spring, Summer, Fall, Winter Unknown High High 1 Time of year may vary depending on climatic conditions as warm year activity can occur all year round. Scatter baiting does not occur under moist conditions. Control of burrowing rodents would be performed in compliance with District s The Control of Oversight of Pesticide Use (District ISO procedure Q751D02), California Department Fish and Game (CDFG) Pesticides Regulation, June 2011 Page 2-10

36 Section 2.2 Maintenance Activities CHAPTER 2 US EPA s injunction settlements, and US EPA Guidelines on pesticides use as described in the US EPA March 2000 Bulletin Protecting Endangered Species: Interim Measures for Use of Pesticides in Santa Clara County to avoid potential impacts to environmentally sensitive species. Poison Bait Rodenticides The poison bait method involves distributing bait, usually grain-based, which is put in bait stations or broadcast mechanically or by hand. The bait is relatively effective and could be distributed in several different ways, depending on the situation. Anticoagulants and zinc phosphide could be used for burrowing rodent control. The District could also use strychnine, which is particularly effective in controlling gophers on the dam faces. Applications of poison bait would be made in mid-spring through fall, occasionally during the winter depending on climatic conditions. The appropriate time for baiting is related to vegetation more than calendar dates. The best time is when herbaceous vegetation is brown and dried out and green vegetation is not present. This period usually corresponds with when young rodents emerge from their burrows. Dispersal of Poison Bait Three types of dispersal of poison bait rodenticides are identified in the DMP. These dispersal methods include: Scatter baiting Spot baiting, and Bait stations With scatter baiting, the bait is broadcast over the entire problem area. Scatter baiting is considered a more efficient method for distributing poison bait because it uses the least amount of bait of all the distribution methods (bait stations involve using a large amount of bait in one place) while still achieving sufficient control. The other advantage of scatter baiting is that it takes advantage of the natural foraging habits of burrowing rodents. Burrowing rodents are somewhat territorial and also quick seed gatherers. If the bait is too close together or piled up, fewer rodents will have access to it. When the bait is spread out evenly, more rodents are able to consume a lethal dose. Spreading out bait is effective for rodent collection as they will scan large areas and have a keen sense for single grains of food, while other non-target organisms do not. Spot baiting, which is applying bait only to problem areas instead of all over like scatter baiting, would be used in areas such as near waterways and property boundaries. Spot baiting could also include placing small amounts of bait inside a burrow; this is also called burrow baiting. June 2011 Page 2-11

37 Section 2.2 Maintenance Activities CHAPTER 2 Bait stations would be used in areas where scatter baiting is not feasible (e.g., because of special status species or because of other uses, such as recreational trails). Bait stations reduce exposure to non-target species (including humans). The bait station is a modified inverted T design, which consists of a 45-degree polyvinyl chloride (PVC) elbows and pipe placed on each entrance of the traditional stations such that the entrance to the station is 12-inches above ground level. The modified bait station is designed to limit access to non-target species. Poison bait would not be piled as this would create an unacceptable hazard to non-target species. Target rodents can easily find the bait when it is spread out. Scavengers and dogs can be affected by the toxicity that remains in the dead carcasses of animals that have consumed this bait. For this reason, the DMP requires that carcasses be disposed of immediately (i.e., daily or more often). Poison Bait: Anticoagulants The active ingredients in anticoagulants are chlorophacinone and diphacinone (at either 0.005% or 0.01% concentration), two of US EPA s ten regulated rodenticides. These two chemicals appear on the 2010 EPA injunction list and, as such, will not be used where habitat for California tiger salamander is present until such time as approval by USFWS is granted. Carcasses can contain chemical residue, which may harm potential scavengers; therefore, the District will remove any carcasses on a daily basis from the start of the application of the anticoagulants until after the treatment ends as part of the rodent control program. If the District chooses to use anticoagulants as baits, bait stations are currently the only form of dispersal available to the District (per US EPA regulations) but, should this change in the future, 0.005% chlorophacinone or 0.01% diphacinone concentrations of the anticoagulants could be used for scatter and spot baiting. Poison Bait: Zinc Phosphide Zinc phosphide (ZnP) is acutely toxic to birds, fish, and other wildlife and would be handled with great care. ZnP is the only acute toxicant that is registered for control of rodents. ZnP is listed under the US EPA s risk management decision for ten rodenticides. At this time, use of this rodenticide is limited to dispersal via bait stations. Scatter and spot baiting are effective methods for ZnP bait due to the rapid onset of symptoms; however, if the squirrels do not consume a lethal dose quickly (54 grain kernels) and recover, they may become bait shy, or learn to avoid poison bait. If allowed in the future, June 2011 Page 2-12

38 Section 2.2 Maintenance Activities CHAPTER 2 scatter and spot baiting would be applied only in problem areas or scattered over areas with boulders to get bait between boulders. Spot baiting would be used in areas near waterways and property boundaries. ZnP could be used inside a rodent burrow (burrow baiting) where it would not be accessible from outside the burrow. The 2.0 percent ZnP concentrations would be used for scatter and spot baiting. The District may use ZnP only once per season in an area that, in previous years, had not responded to anticoagulants. Poison Bait: Strychnine Strychnine-treated grain bait is the most common type used for pocket gopher control. This bait generally contains 0.5% strychnine and is lethal with a single feeding. Strychnine appears on the 2010 US EPA injunction list and, as such, will not be used where habitat for California tiger salamander is present until such time as approval by USFWS is granted. Strychnine would not be applied in a way that would result in contact with workers, other persons, pets, or domestic animals. Applicators would use personal protective equipment including chemical resistant gloves, eye protection, and dust masks. Strychnine is currently registered for use only below-ground as a bait application to control pocket gophers. The end-use products are formulated as a grain-based bait or a paste. The District would use strychnine for control of gophers because anticoagulants do not work as well on gophers. Baiting would be applied manually to burrows. Fumigant Rodenticides Fumigants are toxic gases or vapors that are introduced into the rodent burrow system. This is an effective method of control because it provides quick results and it introduces relatively low levels of toxicity into the environment. Fumigant: Gas Cartridges Gas cartridges are fairly safe to use and are considered relatively non-toxic, except for the gas produced while burning. Gas cartridges are ideal control materials when there is a risk of exposure to wildlife because the toxic gas is limited to the burrow and the risks to non-target species is reduced. Fumigants may be used in areas highly infested that are not responding to other treatments. Rodent burrows often have several entrances. The District would attempt to reduce the number of gas cartridges used by first filling in June 2011 Page 2-13

39 Section 2.2 Maintenance Activities CHAPTER 2 all burrow openings. Active burrow entrances will quickly be re-opened by resident rodent populations, while inactive burrow entrances will remain closed. Only active burrows, or those that are re-opened, would be fumigated. The District would only use the amount of fumigant amount specified on the label. When a gas cartridge is ignited, it produces carbon monoxide gas that fills the burrow system. The carbon monoxide induces a loss of consciousness in the animal. Death occurs rapidly with minimal discomfort for the animal. Rodents killed by carbon monoxide pose no threat to scavengers. Fumigant: Aluminum Phosphide Aluminum phosphide reacts with the moisture in the soil and the atmosphere to produce a lethal phosphide gas that is toxic to all mammals. Aluminum phosphide appears on the 2010 EPA injunction list and, as such, will not be used where habitat for California tiger salamander is present until such time as approval by USFWS is granted. Aluminum phosphide comes in pellet form, which is about the size of a small grape. The gas is colorless and heavier than air with a pungent odor. Burrows under or near buildings would not be fumigated for safety reasons. Aluminum phosphide would not be the District s primary method of rodent control. It may be used where baiting is not working on rodents, where strychnine is not working on gophers, and may be used if gas cartridges are not working. Use of aluminum phosphide requires a restricted use permit from the Department of Pesticide Regulation. If aluminum phosphide is used, only a permitted applicator would perform the fumigation. Record keeping would be necessary and would be kept for at least 2 years and made available to Department of Pesticide Regulation or the local agricultural commissioner upon request. In studies on this pesticide, the greatest problems with contamination occurred from lack of strict adherence to the handling guidelines. For more complete protection, the applicator would wear a protective disposable suit. Any clothing worn during aluminum phosphide application would be washed before reuse. Trapping Trapping is not the most effective method of control, mainly because of the high cost of labor required to achieve good results, but it may be an ideal method to use when other methods are not appropriate. Live trapping could be used anywhere and would provide an additional tool for rodent control in places where species-specific bait stations cannot be used, such as areas with environmental or other physical restrictions. June 2011 Page 2-14

40 Section 2.2 Maintenance Activities CHAPTER 2 Live catch traps are used by setting up numerous traps in infested areas. The door closes once the animal is far enough inside the trap and trips a spring. Bait is used in the trap to lure the rodent inside. After trapping, the rodent would be euthanized. All trapped burrowing rodents must be euthanized. It is illegal to relocate and release burrowing rodents into another area. Although birds and other animals can get caught inside traps, live catch traps generally don t seriously harm these non-target animals. Special status and non-target wildlife species that may be incidentally trapped would be released. CDFG requires traps be checked and animals removed at least once daily (CDFG regulation T 14 CCR Sect ). A CDFG trapping license is required for this activity. Live-traps would be covered to provide shade for trapped animals (particularly trapped non-target species) and would also be supplied with water and fleece or other warming material to prevent hypothermia in trapped animals. The traps are generally safe to use in public areas. Traps are disguised to prevent tampering by the general public that could result in injury. In situations where other methods are not effective or feasible, kill traps will be used. In order to minimize possible harm to non-target species, kill traps will be buried within a burrow. Where there is the possibility of special status non-target wildlife being harmed, permits from the appropriate wildlife agency will be required. Shooting Shooting is another option that may be used to control ground squirrels. This method would not be used too frequently as it is not as effective because squirrels learn to recognize the sound, and is a time intensive method. Shooting may occasionally be used to eliminate a small number of squirrels where other methods have not been effective. A small team of trained personnel would use air rifles or guns with silencers to control noise. All activity would be within the APE for each dam. Shooting would likely be used for no more than a week at a time as it will become less effective with time. Acrylic bullets would be used that shatter upon impact and avoid the chance that a bullet could ricochet off a rock and result in an accident. The use of acrylic bullets would also avoid potential contamination that can result from lead or other metals. Exclusion Gates The use of exclusion gates involves installing one way gates at the entrances to burrows for one week. Exclusion gates would allow burrowing rodents out of a burrow, but would not allow them back in. Burrows would need to be investigated for occupancy prior to backfilling. Exclusion gate installation may be performed in conjunction with other June 2011 Page 2-15

41 Section 2.2 Maintenance Activities CHAPTER 2 rodent control methods to assess the efficacy of the exclusion gate, as there have been no examples or literature available on the effectiveness of using exclusion gates on rodent holes. The District may find exclusion gates are ineffective to control rodent populations as rodents may return to the area and reopen their burrows from another location. Upon evaluation of the results of the District s use of exclusion gates, the District may choose to discontinue this method or continue to use it in conjunction with other methods if it is at least partially effective. Destruction of Burrows Burrow destruction would also be a part of the burrowing rodent control program and would immediately follow the removal of rodents by any of the means described above. The District would contract with a licensed pest control company to perform the trapping and baiting tasks, and the District maintenance crew would perform the collapsing and re-compacting of the rodent burrows. The activities required for backfilling or destroying burrows would depend upon presence of special status species. Destruction of burrows would commence using mechanical or hand methods or grouting where no sensitive habitat exists or restrictions can be implemented to exclude special status species. The burrows would be dug up, backfilled and re-compacted with the excavated material, or grout by a small maintenance crew. Burrow filling on the dam faces would be performed using small amounts of imported fill material, in addition to the excavated material to restore grade. Serpentine soils would not be disturbed or used for backfilling. Dam faces and access roads do not have serpentine soils, but are comprised of fill material. Compaction would be accomplished by using a hand or gas powered whacker. Small backhoes and other compaction equipment may be used for larger areas. Reseeding would not be necessary. Erosion matting may be used depending on the site conditions and slope of the area disturbed. ACCESS ROAD AND BOAT RAMP MAINTENANCE Access roads are located around and on the top of the dam. These roads allow maintenance crews to access the various equipment and features at each dam and for staff to perform site inspections. Access roads are usually composed of compacted soil, gravel, or aggregate base. Roads degrade quickly over winter months due to rain and topography. Some roads must be repaired yearly. Vegetation growth must be removed from access roads and overhead vegetation must be trimmed so that vehicles can safely pass. Access road repair could also require grading, resurfacing, installing or repairing drainage, and slope stabilization. The District could also construct new access roads within the dam APE, including temporary roads for exploratory field investigations or other work. Boat ramps that the District maintains are located at Almaden Dam and Guadalupe Dam. The ramps are gravel/rock surfaced earthen sloping features that extend from an access road into the reservoir to allow boats necessary for maintenance (such as June 2011 Page 2-16

42 Section 2.2 Maintenance Activities CHAPTER 2 to collect log booms, or during maintenance of the inlet) into the reservoir. These ramps must be periodically bladed and ruts and gullies must be filled and compacted. Boat ramps are maintained when reservoir levels are low enough to allow access to the ramp. Drainage and erosion protection features must be maintained and/or improved as necessary. Boat ramps at other reservoirs where public boating is permitted are generally maintained by the County. EROSION CONTROL, BANK STABILIZATION, AND DRAINAGE Erosion and drainage control may be required at the outlet facilities and at the base of some spillways. Repair of erosion on dam faces and at abutment contacts may also be required. Erosion occurs from heavy flow events, such as during particularly rainy winters. Erosion control could include bank hardening with rock riprap, concrete sandbags, or other permanent methods of erosion control. Some types of erosion may be repaired using a process known as track walking, which involves driving a caterpillar over the entire dam surface and tilling the surface to break up rills and even the surface. Erosion control may also include excavation of erosion features (rills, etc.) and placement of compacted fill to restore original grade. Erosion and drainage control may also be accomplished by installation of additional piping or other structures, often employing construction equipment. Erosion and drainage control may require placement of fill within the ordinary high water mark (OHWM) of the adjacent waterways. These activities may require permits under Section 404 and 401 of the Clean Water Act. EMBANKMENT REPAIR Slump repair is a rare maintenance activity. Slumps are normally associated with earthquakes, although there could be other causes. Slumps are essentially landslides that occur on and in the dam. Embankment repair could be required to repair slumps anywhere on the dam face or cracks on the dam and at the abutments. Repair would involve removal of the slumped or cracked material, and then placement of an engineered fill to replace it. This could include either re-installation of the existing material or installation of new material. DEBRIS REMOVAL District maintenance crews must routinely remove trash and debris that may accumulate or is deposited at dam facilities. Trash such as bottles, cans, and cigarette butts are often found around the facilities. Larger waste such as refrigerators, televisions, and monitors are occasionally illegally deposited in the spillways, parking lots, or other areas. Floating wood debris that accumulates at the log booms needs to be removed annually. Debris, such as trees that may fall down the spillway or along the shoreline within the vicinity of the dams, would also be removed as part of the DMP. Removal of trash and debris would be accomplished by hand for smaller objects and use of equipment for larger objects. All trash and debris would be removed from the site and recycled or reused as practicable. Materials such as woody debris could first be used to enhance the quality of appropriate terrestrial habitats, or as a source June 2011 Page 2-17

43 Section 2.2 Maintenance Activities CHAPTER 2 of firewood or wood chips, before any remaining debris or trash is disposed of at an appropriate waste facility. Maintenance of Dam Appurtenances and Equipment INLET/OUTLET, INCLUDING OUTLET PIPES AND TUNNELS The inlet and outlet facilities on a number of the dams are over 70 years old. Maintenance includes ensuring that all parts are operational, installing new parts, and applying lubrication as necessary. Inlet work can, in some circumstances, be performed with an underwater diver, but is more adequately done in a dry environment in conjunction with reservoir drawdown. Use of a diver would reduce the frequency of reservoir dewatering but would not eliminate the need for occasional dewatering. Outlet pipe and tunnel maintenance includes inspections, replacement of steel liners and pipe, restoration of outlet pipe linings, concrete repairs, and other activities. While some inspections can be performed by remotely operable vehicles, most will require entry by staff. Some inspections and maintenance can be performed while low-flow bypass pipes are used to maintain creek flows below the dams; however, some inspections and maintenance will require either reservoir dewatering or flow bypass by pump over. VALVE SYSTEMS AND HYDRAULIC SYSTEMS Hydraulic system parts for many District dams were originally installed in the 1930s. Every year the District has one or two failures of the hydraulic systems. Maintenance of valve and hydraulic systems includes testing, repair, and replacement of parts, including hydraulic power systems, hydraulic lines, hydraulic cylinders, valves, and sluice gates. This work requires repairs, removal (for access), or replacement of fish screens or trash racks located on the intake structure. Valve and hydraulic system repair is either performed through reservoir drawdown or using divers. SEDIMENT REMOVAL AROUND INLET STRUCTURES AND HYDRAULIC LINES Sediment removal is necessary to maintain the functionality of intakes and hydraulic systems/ structures located underwater. Sediment builds up along the upstream side of the dam, often blocking the valves and intakes. Sediment removal involves either underwater methods of removal or would occur during reservoir dewatering by using equipment to excavate sediment. Wet sediments would be stockpiled in a designated area to dry prior to hauling to an appropriate waste facility. Sediments from Almaden, Guadalupe, and Calero Reservoirs may be contaminated with mercury and would be tested and disposed of at an appropriate facility. June 2011 Page 2-18

44 Section 2.2 Maintenance Activities CHAPTER 2 CONCRETE STRUCTURE REPAIRS, REPLACEMENT, AND CLEANING The repair and replacement of concrete structures would be done to maintain the function and integrity of dam structures. Concrete repair may include patching cracks and spalling, and replacing large panels on the following structures: Spillways; Upstream Panels; Dragon s Teeth; Blockhouses, Control Buildings, Intake Structures, Outlet Structures; Outlet Channel and Tunnel (currently Coyote and Lenihan Dams). Concrete structure cleaning would include cleaning of weep holes and expansion joints, as well as the control of rodent populations within blockhouses and control buildings. Repair of weep holes would also include refilling of voids behind the weep holes where the original gravel has been lost. The weep holes themselves would not be filled, only the voids behind the holes. SEEPAGE MONITORING SYSTEMS Monitoring of seepage at all dam locations is necessary to ensure the integrity and safety of the dam structures. Seepage monitoring maintenance includes cleaning debris from weirs, repairing concrete seepage monitoring structures or portions of seepage pipes, vegetation removal, and re-grading areas to ensure seepage flows to the weir. These activities may require additional ground disturbance such as excavation of pipes or grading in wetland areas. Uvas, Coyote, and Stevens Creek dams will require the installation or modernization of existing seepage systems, as may any other facility in the future. If seepage monitoring should indicate that seepage is excessive, seepage control could be required. This could include grouting areas of the dam faces or below the dam faces using a drill rig or by another means. These activities are included in the DMP. OTHER APPURTENANCES Control systems and instrumentation systems are often located in blockhouses or control structures on the dam crests, off to the side of the dams, in the intake structure (Coyote Dam only), or outlet structures. Control systems require periodic maintenance to ensure functionality. Animals, storms, and old age can cause damage to these systems. Repair, replacement, and maintenance of electrical and power systems are included in this task. Control, electric and power system testing, repair, and replacement is periodically required and would be conducted by District maintenance crews of one to two people in a truck or other vehicle. June 2011 Page 2-19

45 Section 2.2 Maintenance Activities CHAPTER 2 Minor appurtenances may require maintenance, repair, and/or replacement at any of the dam facilities. These structures may require localized ground disturbance for installation and repair. Minor appurtenances include (but are not limited to): Piezometers Radial Gates/Tainter Gates Log Booms Siphons and Pumps Stream Flow Weirs Sump Pumps Survey Monuments Accelerometers Inclinometers Robotic Total Stations Fences/Gates Guardrails/Handrails Paint/Coating Graffiti removal Radio Antennae Security Grating Spillway Station Numbers Stairs and Ladders Telephone Service Cables Conduits Conductors Inspections, Monitoring, and Exploratory Work INSPECTIONS AND MONITORING The DMP includes conducting inspections and monitoring as required by District policy and various regulatory agencies, such as DSOD and FERC. Inspections and monitoring would occur on the ground, underground, or underwater. Underwater inspections may be conducted with divers or remotely operated vehicles (ROV). Other inspections may include manual outlet pipe and tunnel inspections and walking around the facilities to inspect various dam facilities. Inspections and monitoring would occur on a regular basis and would involve field visits to the area of the inspection or monitoring. Inspections often involve cycling the inlet and/or outlet valves and sluice or radial gates. Inspections and monitoring involve taking readings from equipment and/or observing structure and feature conditions. If a problem is identified during an inspection, maintenance may be required. Most maintenance is identified in the DMP; however, if the problem requires a large-scale remedy (i.e., construction of a new outlet) it may be considered beyond the scope of the DMP and would require separate environmental review. Surveys and monitoring may include: Surveying crews conducting elevation and horizontal surveys or resurveying monuments, and taking inclinometer readings. Staff taking readings from piezometers and weirs. Biologists monitoring vegetation or wildlife populations. Staff monitoring the continued processes and progress of cracks, erosion, and other geologic processes, etc. June 2011 Page 2-20

46 Section 2.2 Maintenance Activities CHAPTER 2 EXPLORATORY WORK Exploratory trenches and borings are used to evaluate the integrity and safety of the dams. Trenches may be excavated with backhoes or other large equipment. Borings are drilled using drilling rigs. Borings may require minor grading to create a temporary road and level pad to set up the drilling rig, and to provide access to the site. These could be required on the dam, the abutments, or near the toe of the dam. After exploratory work, the borings or trenches would generally be backfilled and compacted to the previous grade. Exploratory work could also include drilling borings from barges stationed in the reservoirs. A drill would be secured to a barge, which is approximately 15 feet by 20 feet in size. The barge would be floated into position and tethered in place with heavy anchors and possibly land lines. The hole would be drilled through steel casings extending from the top of the barge through the water and into the bottom of the reservoir. The casings penetrate to a depth of about 10 feet into the reservoir bottom to obtain a tight seal between the reservoir waters and the boring hole. Reservoir Dewatering Reservoir dewatering would sometimes be required for the inspection, periodic maintenance, and repair of inlet, outlet, and other underwater appurtenances at the dams. The degree of drawdown required may vary by maintenance activity and impacts to downstream habitats can vary greatly among dam locations according to the amount of dewatering required and climate conditions. Dewatering for necessary DMP activities is expected to take approximately one year to complete even though the actual maintenance work would not likely exceed a couple of months. Drawdown includes the time to drain the reservoir, complete the maintenance work, and fill the reservoir up for normal operations. Reservoir drawdown would begin several months prior to the final drawdown period as most reservoirs do not have large outlets; accordingly the District would release water in a manner that would avoid downstream erosion and flood potential. Likewise, it may take one full rainy season or more to refill the reservoir to normal levels. Impacts associated with dewatering are discussed at a broad level based on information reasonably available at this time. When dewatering is necessary as part of the DMP, the potential impacts will be further evaluated in a project-level CEQA analysis before the dewatering occurs to determine if the effects are adequately covered by this PEIR. June 2011 Page 2-21

47 Section 2.3 Dam Maintenance Process and Implementation CHAPTER DAM MAINTENANCE PROCESS AND IMPLEMENTATION IMPLEMENTATION OF DAM MAINTENANCE PROGRAM Identifying Work Maintenance work would be proposed as either part of an Annual Maintenance Work Plan or as work identified later in each year through individual work orders. WORK ORDERS Scheduled preventative maintenance and corrective maintenance would be proposed in work orders. The Manager of the DMP, working with infrastructure, operations, and maintenance staff, would prepare the schedule for implementation of work orders. ANNUAL MAINTENANCE PLANS The District s Water Utilities Operations Division has adopted a plan known as Asset Management for the Water Utility Operations Division dated October 31, The plan focuses on workflow processes, maintenance planning, defining maintenance types (corrective maintenance, preventative maintenance, planned work, etc.), asset hierarchies, and computerized management maintenance system (CMMS). The District will prepare an updated plan once tasks have been carried out in the current plan and the process outlined in the plan has been institutionalized. The plan includes an Annual Maintenance Work Plan (AMWP). If the DMP is approved, the District s dam maintenance activities will be included in the AMWP. The AMWP will be integrated into the CMMS and include known routine maintenance for the upcoming year at each dam facility. DMP Project Determination and Resource Protection Protocol The DMP (located in Appendix VI) includes resource protection protocol and processes that guide program implementation. An Environmental Planner would review work orders to ensure environmental commitments are included in the work order PROGRAM EVALUATION Annual Evaluation A record of all maintenance activities conducted on each dam would be kept for an annual program evaluation which would include review of the comprehensive list of work and BMPs applied during the year. After the first two years of annual reporting, the District may decide to go to a biennial reporting system upon concurrence with resource agencies with jurisdiction over the program. District staff would hold a meeting to evaluate the effectiveness of both resource protection and maintenance methods used in the preceding construction season. The information would be used to update BMPs and the DMP process to create a greater understanding of June 2011 Page 2-22

48 Section 2.3 Dam Maintenance Process and Implementation CHAPTER 2 how to accomplish environmentally sensitive, fiscally sound, and timely maintenance work. The meeting would include technical staff, environmental planners, engineers, supervisors, and facility staff. Discussions would include: BMP implementation successes and failures; Staff communication problems and successes; Agency communications and coordination feedback; Capital expenditures and staff resources; Adaptive management: suggestions for improvement, including additional staff training requirements and process changes. Program effectiveness would be evaluated against the District s Ends Policy, DMP resource protection objectives (see below and in Chapter 4 of the DMP), compliance with mitigation and BMPs identified in this PEIR, and compliance with all permit conditions. An annual evaluation report would be prepared and submitted to any regulatory agency that had jurisdiction over the work performed during the year. The report would include records of all work and work plans. Program Evaluation and Adaptive Management Program improvement ideas would be presented in the annual evaluation report and would include justifications for any changes to existing protocols (adaptive management). The improvement ideas must include costs and benefits, protocol changes, permit compliance, and an evaluation of any new potential impact to environmental resources subject to review by an environmental planner. Program improvements would be incorporated as an addendum to the DMP, subject to approval by District management and legal staff. June 2011 Page 2-23

49 Section 2.4 Environmental Protection Policies and Practices CHAPTER ENVIRONMENTAL PROTECTION POLICIES AND PRACTICES INTRODUCTION The DMP includes various environmental protection policies and practices incorporated into the program, including resource protection policies that are included in the DMP and standard District BMPs. This PEIR identifies a number of mitigation measures that will be adopted by the District to avoid, minimize, or compensate for potentially significant impacts that may result from dam maintenance activities. In addition, resource agencies will likely require permit conditions as part of their approvals of the program RESOURCE PROTECTION POLICIES Eight DMP resource protection policies have been developed to guide decision-making for dam maintenance projects. These policies were adopted from the Stream Maintenance Program (SMP) and Pipeline Maintenance Program (PMP) policies and modified as suited to dam maintenance work. The policies support the goals, which the procedures and practices fulfill. DMP Policies are based on the objectives outlined in Chapter 1 of this PEIR and are means to the District s Ends Guidelines. All dam maintenance must adhere to these policies. The policies are listed below by categories. Each policy with an explanation is included in Table of the DMP. Process and Protocols Objective 1: The District will process all routine dam maintenance activities according to the process and protocols established in Chapter 3 of the DMP. Objective 2: The District will continue to develop, implement, and update standard practices for implementation of dam maintenance activities to ensure that they are conducted in an effective and environmentally sensitive way and are technically feasible and economically feasible. Protection of Native Species Objective 3: The District will implement feasible measures to avoid and minimize impacts to native species, especially special status and riparian-dependent species. Compensate for Removal of Wetland and Riparian Habitat Objective 4: Wetland and riparian habitats will be avoided to the extent feasible to minimize impacts on water quality, wetland hydrology, and sensitive species. Any unavoidable riparian and wetland impacts would be mitigated. Protection of Water Quality Objective 5: The District will take measures to reduce increases in short-term stream turbidity and/or increases in stream temperature and other water quality impacts that can result from dam maintenance activities. June 2011 Page 2-24

50 Section 2.4 Environmental Protection Policies and Practices CHAPTER 2 Hazardous Material Management and Control Objective 6: The District will implement feasible measures to ensure that hazardous materials are properly handled and the quality of water resources is protected. Cultural Resource Protection Objective 7: Measures will be implemented at work sites to ensure that the potential for significant impacts to previously undiscovered cultural resources are mitigated to the extent feasible. Additional Work Site Management Practices Objective 8: Dam Maintenance Projects will be implemented to avoid or minimize the potential for short-term noise nuisances, short-term aesthetic nuisances (lighting), and short-term air quality impacts to the surrounding community RESOURCE PROTECTION MEASURES Dam Maintenance Program Best Management Practices SELECTION OF BMPS The District has defined BMPs as standard preventive measures that are routinely incorporated into District activities and operations. When a project requires additional or more specific avoidance or minimization measures, such practices and/or measures are evaluated during the environmental review process as project specific mitigation measures. Not every BMP is designed to be used in every situation. Since BMPs are meant to be specific to particular activities and resources, implementation of an appropriate set of BMPs for each project is a key element to the program s effectiveness. Because of variation in District facilities and the tendency of individual site conditions to change over time, conditions under which each BMP must be applied cannot be strictly prescribed. The staff involved in design and implementation of the maintenance activity must retain some flexibility to determine which BMPs should be implemented according to design objectives and site conditions. Applicable BMPs for the proposed activities were established based on impacts as identified in the PEIR. Chapter 2 of the DMP identifies all of the activities and subtasks involved in the maintenance of the dams and associated facilities. The District has also worked to develop special procedures for protection of particular resources. These procedures are meant to be carried out for all District operations as applicable. For example, the District has developed procedures for protection of nesting birds that would be incorporated into this program. Any other appropriate procedures that may be developed in upcoming years would also be appended to the DMP, as appropriate. June 2011 Page 2-25

51 Section 2.4 Environmental Protection Policies and Practices CHAPTER 2 IMPLEMENTATION AND MONITORING OF BMPS Implementation and monitoring of BMPs would be carried out by lead staff assigned to a specific activity, with the assistance of other qualified staff where the individual BMP requires a particular field of expertise (i.e., water quality sampling, avian surveys and monitoring, fisheries monitoring). Qualified staff is included in the existing work order process as a resource for BMP implementation in these instances and would continue to be under this new program. The BMPs would be implemented as they are specified in the work order. If site conditions or other factors require a BMP to be changed or make it no longer relevant to the project, the assigned lead on the job would consult with appropriate staff (Manager of the DMP, qualified environmental staff, etc.) and obtain authorization to modify the BMPs. Resource agencies (such as CDFG or USFWS) would be consulted if the measures are related to biological resource. Modifications to BMPs would be noted as an addendum to the work order. BMPS AND FUTURE CHANGES TO BMPS BMPs presented in this document are part of the project description of the DMP and have been selected for the purpose of minimizing impacts that may otherwise result from DMP activities. The BMP section of the DMP is intended to be a living document and to change over the life of the program. The annual review of the DMP (as discussed in Chapter 3 of Appendix VI) includes an evaluation step to review the effectiveness of and improve upon aspects of the maintenance program, including the BMPs. As BMPs are used and ways are seen to improve their effectiveness, they will be modified to reflect the changes. As new BMPs are developed or technology improves, the program will incorporate them to further protect resources. Reporting on modification to BMPs made as a result of the annual project reviews for adaptive management will be done as part of the normal reporting practices called out in the DMP. Dam Maintenance Program Mitigation Measures Mitigation measures are incorporated into the DMP as a result of the environmental impact analysis in this PEIR. These mitigation measures are presented in the individual resources sections and included in the Mitigation Monitoring and Reporting Program in Appendix V. Mitigation also includes compensatory mitigation for effects to wetlands, riparian habitat, trees, special status plant species, and special status wildlife species such as California red-legged frog, California tiger salamander, and San Francisco dusky-footed woodrat. Compensation mitigation measures are defined in Section 3.2 Vegetation and Habitat and Section 3.3 Wildlife. June 2011 Page 2-26

52 Section 2.4 Environmental Protection Policies and Practices CHAPTER 2 Dam Maintenance Program Permit Conditions Some activities identified in the DMP would require a permit from federal, state, or regional agencies. Agencies will often stipulate specific conditions that must be employed or implemented with the issuance of a permit. The District would be subject to meeting all conditions and requirements identified in a required permit prior to undertaking a maintenance activity. Permit Conditions are listed and tracked in the District Permit Management System. A list of the permits the program would need to acquire is provided in Table 1.4-1, in Chapter 1. June 2011 Page 2-27

53 CHAPTER 3. SETTING AND IMPACT ANALYSIS 3.1. SETTING AND IMPACT ANALYSIS INTRODUCTION OVERVIEW This section of the PEIR presents the findings of the environmental analyses conducted for the proposed project activities. Analyses were conducted for each of the following key environmental areas: Vegetation and Habitat Wildlife Hydrology and Water Quality Hazards, Hazardous Materials, and Human Health and Safety Cultural Resources Geology, Soils, and Mineral Resources Noise Air Quality Traffic and Transportation Recreation Aesthetics and Visual Resource Utilities and Service Systems Agriculture, Land Use, Population and Housing, and Public Services are not included in this PEIR because the analysis conducted for the Initial Study and as discussed in Chapter 1 showed that there would be no effects of the proposed project on these resource areas. Each of the analytical sections in this Chapter identifies the: Environmental Setting Regulatory Setting Significance Criteria Impacts, Mitigation Measures, and BMPs ENVIRONMENTAL SETTING The environmental setting sections present a description of the physical environment for each environmental parameter. The content and level of detail of the environmental setting is relative to the extent of the potential impacts that could occur from project activities REGULATORY SETTING Current regulatory settings are presented in the Regulatory Setting section. Federal, state, regional, District, and local regulations applicable to the program area are identified. June 2011 Page 3-1

54 Section 3.1 Setting and Impact Analysis Introduction CHAPTER SIGNIFICANCE CRITERIA The significance criteria discussions for each environmental parameter identify the thresholds of significance against which a potential impact was evaluated. Thresholds of significance are based on: Environmental Checklist Form prepared by the District; District Ends Policies; Other local, state and federal regulations; and Professional judgment based on knowledge of the program activities and the existing environment IMPACTS, MITIGATION MEASURES, AND BMPS The results of the environmental analyses conducted for the proposed project are presented in Sections 3.2 through 3.13 of this Chapter of the PEIR for the proposed action. For each potential effect, a determination is presented as to whether or not the proposed project would result in a significant environmental impact. The DMP includes more than 65 individual maintenance activities. Not all of the activities would have environmental effects on resources. The activities have been grouped, for the purposes of environmental review, into four main categories based on the types of effects. The four primary categories of DMP activities are: 1. Surfaces work and/or earthwork (includes vegetation management, burrowing rodent control, erosion control, bank stabilization, and embankment repairs, access road and boat ramp repairs, and debris removal) 2. Maintenance of dam appurtenances and equipment 3. Inspections, monitoring, and exploratory work 4. Reservoir Dewatering The impact assessment includes discussion of both BMPs and mitigation measures, which reduce environmental effects of project actions. A BMP is a technique or methodology that is regularly included into District projects and activities that, through experience and research, has proven to reliably avoid or minimize environmental impacts. BMPs are an integral part of the project description, while mitigation measures are presented in the environmental assessment to reduce any remaining potentially significant environmental effects that could arise from implementation of project activities. BMPs are identified in the impact analysis as they are applied to reduce environmental effects. June 2011 Page 3-2

55 Section 3.1 Setting and Impact Analysis Introduction CHAPTER 3 The District maintains a handbook of BMPs (document number WW75109, version D, effective August 2010). These are the District s standard measures employed in projects to reduce or avoid impacts. The full wording of the measures is included in the Mitigation Monitoring and Reporting Program (Appendix V). BMPs may be updated through annual review and adaptive management practices. In the event that BMPs are revised in the District s BMP Handbook, the District shall ensure that for each BMP listed, equal or greater environmental protection is retained. Impact discussions are followed by mitigation, where applicable, to reduce impacts resulting from the DMP to less than significant levels. Mitigation measures presented in this DMP are specifically designed to reduce potentially significant effects of maintenance actions. Mitigation also includes compensatory mitigation for potential effects to wetlands, trees, special status plants, and special status animals. June 2011 Page 3-3

56 Section 3.2 Vegetation and Habitat CHAPTER VEGETATION AND HABITAT ENVIRONMENTAL SETTING Methods The majority of site visits were conducted between February 2006 and October 2008 by Live Oak Associates, Inc. to evaluate existing site conditions and potential impacts on biological resources from project DMP activities. Additional information on sensitive natural communities and special-status plant species was also compiled from the following sources: Inventory of Rare and Endangered Plants of California (CNPS 2010) California Natural Diversity Database (CNDDB) (CDFG 2010) Endangered and Threatened Wildlife and Plants (USFWS 2010) Annual Report on the Status of California State Listed Endangered, Threatened, and Rare Plants and Animals of California (CDFG 2005) California s Wildlife, Volumes I, II, and III (Zeiner, et. al., 1988a, b, c) Santa Clara Area Soils (NRCS 1958) Santa Clara Area, Eastern Part Soils (NRCS 1974) Preliminary Geologic Map of the San Jose 30 x 60-Minute Quadrangle, California (USGS 1999) A Manual of California Vegetation (Sawyer, Keeler-Wolf and Evans, 2 nd ed. 2008) Preliminary Description of the Terrestrial Natural Communities of California (Holland 1986) Occurrence data from District botanical surveys and from District botanist regarding special status habitats and associated species Botanical survey work conducted in 2009 and 2010 by H.T. Harvey and Associates on the dam faces for the Rodent MND (SCVWD 2010c) List of California Terrestrial Natural Communities Recognized by The California Natural Diversity Database (CDFG 2003) Vegetation mapping was based on field reconnaissance surveys that provided visual coverage of each of the 14 dam project areas combined with the use of high resolution aerial photographs taken in 2001 (Triathlon Ltd. 2002) at a general scale of 1 inch to 100 feet, U.S. Geological Survey (USGS) quadrangles, and AutoCAD engineering maps provided by the District that include topography and planimetry with superimposed, thematic GIS data layers created for each dam. Upland habitats were mapped with June 2011 Page 3-4

57 Section 3.2 Vegetation and Habitat CHAPTER 3 detailed precision on the high resolution aerials according to field signatures, and aquatic habitats were mapped according to the Corps of Engineers Wetlands Delineation Manual (USACOE 1987) and Minimum Standards for Acceptance of Preliminary Wetland Delineations (USACOE 2001) with sub-meter accuracy. Where possible, potential Waters of the United States were mapped using a GPS unit (SCVWD 2008). In addition to federally-protected wetlands and waters, state-protected wetlands were also evaluated and mapped. Vegetation communities were then evaluated in conjunction with guidelines provided by A Manual of California Vegetation (Sawyer et al. 2008), Preliminary Description of the Terrestrial Natural Communities of California (Holland 1986), the Draft Santa Clara Valley Habitat Plan (Santa Clara County 2010), and Corps of Engineers Wetlands Delineation Manual (USACOE 1987). The classification of natural communities follows the Draft Santa Clara Valley Habitat Plan (Santa Clara County 2010), and Sawyer et al. (2008). Protocol-level special status plant species surveys were conducted in August 2006, October 2006, March 2007, and June 2007 by Live Oak Associates, Inc. at nine dam project areas that support suitable habitat for special status plant species. Surveys were conducted in accordance with the Botanical Survey Guidelines (CNPS 2001) and Guidelines for Assessing the Effects of Proposed Projects on Rare, Threatened and Endangered Plants and Natural Communities (CDFG 1997). During each survey, the entire project areas were walked, ensuring 100 percent visual coverage. Emphasis was placed on areas supporting suitable habitat. When special status plant species were observed, population sizes were estimated either by counting all individuals or sub-sampling areas and extrapolating the data to estimate population size. Identified populations were mapped using a GPS with sub-meter accuracy where possible. In instances where populations could not be mapped due to site specific circumstances (vertical cliff, dense canopy coverage, etc.), the high resolution aerial photography and topographic maps at a general scale of 1 inch to 100 feet were utilized to map population locations. CNDDB forms were completed to document each rare plant population occurrence. All vascular plant species observed were recorded in a field notebook and a complete list of documented species was compiled (included in Appendix II). An updated plant species list for the dams (all except Anderson, Coyote, Coyote Percolation Ponds, Calero-Fellows and Rinconada Treated Water Reservoir dams) was compiled in 2009 and 2010 (SCVWD 2010c; Appendix II) Existing Conditions SOILS The geology and soils on and surrounding each dam influence the vegetation and habitat types found. All but one of the 14 dams were built of rolled earth with two dams also incorporating rock fill (Anderson and Uvas); Coyote Percolation Ponds Dam is an exception because it is a concrete dam with steel flashboards. The earthen dams were created from fill material, which differs in soil composition and slope from the surrounding habitat. Soils beneath dam faces and in the surrounding habitats within the project boundaries fall into 19 different soils series as shown in Table (NRCS 1958; 1974). June 2011 Page 3-5

58 Section 3.2 Vegetation and Habitat CHAPTER 3 Only two of the soil series directly contribute to biologically sensitive habitats: Riverwash, which is associated with onsite creeks, and the Climara and Montara Series, which are derived from serpentine. Where present, the Riverwash soils underlie the creeks downstream from the outlets and spillways. Montara soils are present at Almaden, Calero Main, and Chesbro dams and immediately adjacent to Anderson Dam. Soils maps are located in Appendix III. Climara soils are present at Coyote Dam. Serpentine bedrock underlies portions of the project areas at Almaden, Anderson, Chesbro, and Guadalupe dams (USGS 1999). Table 3.2-1: Soils Underlying the Project Areas Soil Series/Soil Map Surface Drainage Parent Material Symbol Perm. Class Hydric ARBUCKLE SERIES Alluvial materials from Moderately Well drained No Arbuckle loam, deep, 5-9% slopes AkC mainly conglomerate and metasedimentary rocks slow to slow CLIMARA SERIES Mass movement Slow Well drained No Climara stony clay, 15-50% slopes CmE deposits derived from Franciscan mélange serpentine, serpentinite, graywacke, chert, gabbro and blue schist and other ultrabasic rocks. CORTINA SERIES Cortina very gravelly loam, 0-5% slopes GARRETSON SERIES Garretson loam, gravel substratum, 0-2% slopes Garretson gravelly loam, 0-5% slopes Garretson fine sandy loam, 0-2% slopes GAVIOTA SERIES Gaviota gravelly loam, 30-75% slopes, severely eroded GILROY SERIES Gilroy clay loam, 30-50% slopes Gilroy clay loam, 50-75% slopes KEEFERS SERIES Keefers clay loam, 2-9% slopes, eroded LOS GATOS SERIES Los Gatos gravelly loam, 50-75% slopes MOCHO SERIES Mocho soils, undifferentiated MONTARA SERIES Montara rocky clay loam, 15-50% slopes, eroded Montara stony clay loam, 30-50% slopes, severely eroded CoB GaA GbB GpA GhG3 GoF GoG LfG Mk MwF2 MxF3 Gravelly alluvium from mixed rock sources Medium-textured alluvium, dominantly from sedimentary formations Material weathered from hard sandstone or meta-sandstone Material weathered from basic igneous and metamorphic rocks Mainly from basic igneous rocks Residuum from sandstone, shale, and metasedimentary rock Alluvium derived mostly from sandstone and shale rock sources Material weathered from serpentinitic rocks Rapid Somewhat excessively drained Yes Moderate Well drained No Moderately rapid Moderately slow Well and excessively well drained Well drained No No Slow Well drained Yes Moderate Well drained No Moderate or moderately slow Moderately slow Well drained Well drained No No June 2011 Page 3-6

59 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-1: Soils Underlying the Project Areas Soil Series/Soil Map Surface Drainage Parent Material Symbol Perm. Class Hydric PERMANENTE SERIES n/a Moderate Excessively No Permanente stony loam, 50-75% PhG3 drained slopes, severely eroded PITS PkG Excavated substratum n/a n/a No material from Yolo and Soper series PLEASANTON SERIES n/a Moderately Well drained No Pleasanton gravelly loam, 0-2% PpA slow slopes Pleasanton gravelly loam, 2-9% PpC slopes Pleasanton gravelly loam, 9-15% PpD2 slopes POSITAS SERIES Alluvial material from Slow and Moderately No Positas-Saratoga loams, 2-9% PrC mixed rock sources very slow well drained slopes Positas-Saratoga loams, 9-15% PrD slopes RIVERWASH Rg n/a n/a n/a Yes SARATOGA SERIES n/a Moderately Well drained No Saratoga-Positas loams, 15-30% SgE slow slopes SOPER SERIES Material weathered from Moderately Well drained No Soper gravelly loam, 15-30% ShE2 conglomerate and slow slopes, eroded sandstone Soper gravelly loam, 30-50% ShF slopes VALLECITOS SERIES Metamorphic bedrock Slow Well drained No Vallecitos loam, 15-30% slopes, VaE2 eroded YOLO SERIES Fine-loamy alluvium Moderate Well drained No Yolo silty clay loam, 0-2% slopes YeA derived from sedimentary formations SOURCE: NRCS 1958; NRCS 1974 June 2011 Page 3-7

60 Section 3.2 Vegetation and Habitat CHAPTER 3 VEGETATION COMMUNITIES The areas surrounding the 14 dams are vegetated by a mosaic of natural and semi-disturbed communities (Table 3.2-2; Figure set III-1 in Appendix III). Nine vegetation communities have been mapped within the project area along with one developed, unvegetated land cover type. They include a grassland land cover type, three chaparral types, four woodland types, and one wetland vegetation land cover community type. While the dam faces are typically modified habitats with few native species present, areas surrounding the dams and reservoirs are comprised of natural vegetation communities. Several of these communities are designated as sensitive natural communities by CDFG (2003) and are discussed in further detail in the Regulatory Context section. They include: Mixed serpentine chaparral Riparian woodland, forest and scrub Coastal and valley freshwater marsh Serpentine grasslands (not mapped) but small inclusions in project area Serpentine seeps (not mapped) but small inclusions in project area Northern coastal scrub/diablan coastal scrub contains the California sagebrush scrub alliance and within that, the California sagebrush-coyote ceanothus association. Found on Coyote Ridge in vicinity of Anderson Dam. A complete list of the plant species observed between the February 2006 and October 2008 field surveys is included in Appendix II. Additional vegetation surveys of the dam faces were conducted in 2009 and 2010 by H.T. Harvey & Associates. No new populations of special status plants were observed during the surveys. GRASSLAND California annual grassland is an herbaceous plant community dominated by nonnative annual grasses. This vegetation type is typically found on the dam faces as well as adjacent to roads and other disturbed areas surrounding the dams. Typical dominant species include nonnative grasses such as Italian rye grass (Lolium multiflorum), wild oat (Avena fatua), rip gut brome (Bromus diandrus), and foxtail fescue (Vulpia myuros), as well as associated native and nonnative forbs such as clovers (Trifolium spp.), filarees (Erodium spp.), lupines (Lupinus spp.), yarrow (Achillea millefolium), and California poppy (Eschscholzia californica). Native, non-serpentine grasslands may occur in a patchy distribution within the larger annual grassland community and are typically comprised of a mixture of nonnative annual grasses with some native perennial grasses (such as Nasella pulchra and Elymus glaucus) and forbs. In areas with serpentine soils, serpentine grassland can occur. Typically this vegetation type is interspersed with rocky serpentine outcrops on shallow soils. Total vegetative cover is low June 2011 Page 3-8

61 Section 3.2 Vegetation and Habitat CHAPTER 3 and comprised almost entirely of native perennial grasses and annual forbs. These inclusions of native non-serpentine grassland and serpentine grassland have been mapped as annual grassland in the project area due to the difficulty of distinguishing this land cover type on aerial photographs. These types would more likely be found in grassland surrounding the dam faces in more natural areas, rather than on the dam faces themselves. CHAPARRAL Chaparral shrub communities are common surrounding many of the dams and reservoirs in the project area. This land cover type includes northern mixed chaparral/chamise chaparral, mixed serpentine chaparral, and northern coastal scrub/diablan coastal scrub. Northern mixed chaparral/chamise chaparral is typically dominated by broad-leaved shrubs forming very dense stands (after Holland 1986 in the Santa Clara Valley Draft Habitat Plan). In the project area this includes communities dominated by coyote brush (Baccharis pilularis) with annual grasses and coyote brush with California sagebrush (Artemisia californica). Mixed serpentine chaparral is generally comprised of shorter-stature shrub species found on serpentine soils and is generally more open and less dense than types found on non-serpentine soils. This land cover type includes communities dominated by a mix of coyote brush and California sagebrush with coyote ceanothus (Ceanothus ferrisae) as an occasional component. This type can contain bigberry manzanita (Arctostaphylos glauca) with mixed shrubs (such as California sagebrush and black sage [Salvia mellifera]). Several special status plant species are found in these vegetation communities. Northern coastal scrub/diablan coastal scrub is composed primarily of evergreen shrubs with an herbaceous understory in open areas; typically this land cover type is found at lower elevations (below 300 ft; cited in the Draft Santa Clara Valley Habitat Plan as Ca Partners in Flight 2004). Vegetation associations in this land cover type have been quantitatively sampled in detail near Anderson Dam on Coyote Ridge (Evans and San 2004), and include coyote brush scrub (found generally on windy exposed sites with shallow soils [Holland 1986 in the Draft Santa Clara Valley Habitat Plan) and California sagebrush-coyote ceanothus shrubland, found on serpentine soils (with foothill pine [Pinus sabiniana], yerba santa [Eriodictyon californicum], and/or hoary coffeeberry [Rhamnus tomentella]). WOODLAND Woodland land cover types include upland tree-dominated vegetation communities such as oak woodland and foothill pine-oak woodland, as well as riparian woodland, forest and scrub communities found along riverine watercourses and stream banks. June 2011 Page 3-9

62 Section 3.2 Vegetation and Habitat CHAPTER 3 Coast live oak woodland and forest includes stands of coast live oak, typically with a California bay (Umbellularia californica) component. Other live oaks and scattered deciduous trees may also be present in this land cover type. Typically the canopy is closed, although grasses and forbs may be found in the understory. This type generally occurs on the north-facing valley slopes and valley bottoms (Draft Santa Clara Valley Habitat Plan 2010). This can transition to mixed evergreen forest, dominated by a mixture of evergreen broad-leafed trees such as California bay, madrone (Arbutus menziesii) tanoak (Lithocarpus densiflorus) and various oaks (coast live [Quercus agrifolia], interior live [Q. wislizenii] and canyon live oak[q. chrysolepis]) on the west side of the valley on north-facing slopes. It has a similar understory to coast live oak woodland and was not called out as separate vegetation land cover type in the project area. Foothill pine-oak woodland is found within the project area in some of the drier foothills surrounding the reservoirs such as Anderson Dam, adjacent to chaparral land cover types and often on serpentine soils. This vegetation type is dominated by foothill pine with a typically dense understory of scattered chaparral shrubs and nonnative annual grasses. At higher elevations foothill pines are joined by blue oak (Quercus douglasii) and mixed oak woodlands. Eucalyptus woodland or semi-natural stands are found adjacent to some dams such as Chesbro, Lenihan and Vasona dams and are typically dominated by blue gum (E. globulus). Understory vegetation is typically depauperate, but can include nonnative grasses as well as scattered shrubs such as toyon (Heteromeles arbutifolia) and monkeyflower (Mimulus aurantiacus). Riparian woodland, forest and scrub land cover types include willow riparian forest, woodland and scrub vegetation types as well as mixed riparian vegetation types. These land cover types are predominantly found downstream of the dams along creeks in the project area. The willow riparian forest and woodland is typically dominated by dense stands of red and arroyo willow and is found along established stream courses. The understory commonly contains mule fat (Baccharis salicifolia) along the margins of more open, sandy areas. The mixed riparian vegetation type can include mature alder (Alnus rhombifolia), sycamore (Platanus racemosa), California bay, cottonwoods (Populus spp.), and oaks; and is found similarly along the margins of the active stream channel. Generally no one species dominates the canopy and composition may vary with elevation, hydrology, aspect, etc. DEVELOPED This land cover type is not vegetated but rather consists of access roads and other developed land features. WETLANDS The majority of wetland vegetation within the project area can be classified as coastal and valley freshwater marsh, dominated by perennial emergent vegetation such as cattails, rushes and bulrush; as well as annual vegetation June 2011 Page 3-10

63 Section 3.2 Vegetation and Habitat CHAPTER 3 such as rabbitsfoot grass (Polypogon monspeliensis), nutsedge (Cyperus eragrostis), willow herb (Polygonum spp.) and water primrose (Ludwigia peploides). Waters of the US and wetlands were mapped in the project area based on surveys from February 2006 to June 2008, as part of a wetland delineation report prepared for the US Army Corps of Engineers (SCVWD 2008). The majority of wetland land cover types are found downstream of the dams along creeks or spillway pools, or along the margins of some of the reservoirs. A serpentine seep is present above the Anderson Dam spillway; however, it was not mapped as jurisdictional for the delineation and is not identified on the delineation maps (see Appendix III, Figure Set III-1 Biotic Habitat Maps). Table 3.2-2: Natural Communities in the Project Area Dam Almaden Anderson Calero Auxiliary Fellows Dike Natural Communities Ruderal/Developed X X X X X X X X X X X X X X California Annual Grassland X X X X X X X X X X X X X X Northern Mixed Chaparral/Chamise Chaparral X X X X X X Mixed Serpentine Chaparral X X X Northern Coastal Scrub/Diablan Coastal Scrub X X X Coast Live Oak Woodland and Forest X X X X X X X X X Foothill Pine-Oak Woodland X Riparian Woodland, Forest and Scrub X X X X X X X X X X X Eucalyptus Woodland X X X Coastal and Valley Freshwater Marsh X X X X X X X X X X Calero Main Chesbro Coyote Coyote Perc. Guadalupe Lenihan Rinconada Stevens Creek Uvas Vasona Sensitive Natural Communities and Special Status Plant Species REGULATORY CONTEXT Rare, threatened and endangered species and their ecosystems and habitats are protected under state (CESA) and federal (FESA) law (see 16 USC 1531 et seq., Sec. 2(b) of the Federal Endangered Species Act and Sec. 2051(c) of the California Fish and Game Code). Under CEQA, disclosure of potential direct and indirect impacts of a project on candidate, sensitive, or special status species or sensitive natural communities identified in local or regional plans, policies or regulations, or by CDFG or USFWS, are required (CEQA Guidelines, Appendix G Environmental Checklist Form). Rare, threatened and endangered plants may include taxa that June 2011 Page 3-11

64 Section 3.2 Vegetation and Habitat CHAPTER 3 have not been listed by state and federal agencies (see CEQA Guidelines, and 15380); similarly, rare natural communities may not contain rare, threatened or endangered species. Such taxa and natural communities are identified and listed in the CNPS Electronic Inventory. There are several provisions of the California Environmental Quality Act (CEQA) Guidelines that address the potential for significant, adverse impacts to rare or sensitive natural communities. These provisions include situations where a rare, threatened or endangered (RTE) plant is a dominant in a vegetation community or in which a RTE animal depends on the community; in these cases impacts to the functioning of the entire community (not just direct impacts to the species) should be addressed and mitigated to the extent feasible. Section IV (b) of the CEQA Checklist asks whether a project would have a substantial adverse effect on any... sensitive natural community identified... in local or regional plans, policies, or regulations (including General Plans or local ordinances) or by resource agencies such as CDFG or the US Fish and Wildlife Service. The CDFG keeps a list of sensitive natural communities in the California Natural Diversity Database (CNDDB; CDFG 2003). Riparian habitats and wetlands are also subject to impact consideration under state and/or federal law (CEQA Guidelines Appendix G; Sec. 404 of the Clean Water Act). Most water bodies and waterways, whether natural or man-made, are subject to laws and regulations due to their value as public resources. These include creeks, streams, rivers, sloughs, estuaries, lakes, reservoirs, stock ponds, artificial lagoons, some percolation ponds, as well as certain pipes, culverts, and canals that connect to natural waters. Many activities that could impact waters and wetlands need to be disclosed in CEQA and NEPA documents, and may also require permits depending on the nature of the impacts or work. Natural communities mapped within the project area and designated as sensitive natural communities by the CDFG (Table 3.2-2; CNDDB; CDFG 2003) include: Mixed serpentine chaparral Riparian woodland, forest and scrub Coastal and valley freshwater marsh Serpentine grasslands (not mapped) but small inclusions in project area Serpentine seeps (not mapped) but small inclusions in project area Northern coastal scrub/diablan coastal scrub contains the California sagebrush scrub alliance and within that, the California sagebrush-coyote ceanothus association. For more information on regulatory context, see Wildlife Chapter 3.3. June 2011 Page 3-12

65 Section 3.2 Vegetation and Habitat CHAPTER 3 Several habitats and species of plants within the State of California have been designated as sensitive due to their limited distributions. Such habitats and species may be considered rare and are vulnerable to extirpation as the state s human population grows, converting undisturbed areas into agricultural and urban uses. State and federal laws have provided CDFG and USFWS with a mechanism for conserving and protecting the diversity of plant species native to the state. A sizable number of native plants have been formally designated as threatened or endangered under state and federal endangered species legislation. Others have been designated as candidates for such listing. Still others have been designated as species of special concern by CDFG. The California Native Plant Society (CNPS) has developed its own set of lists of native plants considered rare, threatened or endangered (CNPS 2006a). Collectively, these plants are referred to as special status species. The extent of sensitive habitats and species in the project vicinity are discussed further below Special Status Plant Species 5 A number of native plants have been formally designated as threatened or endangered under state and federal endangered species legislation. Others have been designated as candidates for such listing. The California Native Plant Society (CNPS) has developed a set of lists of native plants in California according to rarity. List 1B plants are those considered to be rare, threatened or endangered in California and elsewhere, while List 2 plants are those considered rare, threatened or endangered in California but more common elsewhere (CNPS 2010). List 1A plants are presumed extinct in California. Plants on List 1A, List 1B and List 2 meet the definitions of Section 1901, Chapter 10 (Native Plant Protection Act) or Sections and 2067 (California Endangered Species Act) of the California Department of Fish and Game Code, and are eligible for state listing. It is mandatory that they be fully considered during preparation of environmental documents relating to CEQA. Collectively, these plants are referred to as special status species. Other CNPS Lists include List 3- a review list of plants that need more information, and List 4 a watch list of plants of limited distribution. The 7 USGS quadrangles in which the 14 dams or project areas occur as well as the surrounding 20 USGS quadrangles were queried via the CNDDB (CDFG 2010) and CNPS s Electronic Inventory of Rare and Endangered Vascular Plants of California 6 (CNPS 2010) for documentation of special status plant species potentially occurring within the project areas. Endangered and Threatened Wildlife and Plants (USFWS 2010) and the Annual Report on the Status of California State Listed Threatened and Endangered Animals and Plants (CDFG 2005) were also reviewed for information on sensitive species within the project areas. Table is a master list of special status plant species and their potential to occur within the project areas at 9 dams. Table also identifies the regulatory status, habitat, and blooming period for the plants. 5 Also referred to as Sensitive Plants 6 The mission of the CNPS Rare Plant Program is to develop current, accurate information on the distribution, ecology, and conservation status of California's rare and endangered plants, and to use this information to promote science-based plant conservation in California. The Program has developed a reputation for scientific accuracy and integrity and its data are widely accepted as the standard for information on the rarity and endangerment status of the California flora. The CNPS Inventory of Rare and Endangered Plants of California tracks the conservation status of hundreds of plant species June 2011 Page 3-13

66 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Species Status Habitat Blooming Period Potential to Occur Within Project Areas Species Listed as Threatened or Endangered Under the State and/or Federal Endangered Species Act Tiburon Indian Paintbrush FE, CT, (Castilleja affinis ssp. neglecta) CNPS 1B Coyote Ceanothus (Ceanothus ferrisae) Monterey Spineflower (Chorizanthe pungens var. pungens) Robust Spineflower (Chorizanthe robusta var. robusta) Santa Clara Valley Dudleya (Dudleya setchellii) Contra Costa Goldfields (Lasthenia conjugens) FE, CNPS 1B FT, CNPS 1B FE, CNPS 1B FE, CNPS 1B FE, CNPS 1B Serpentinite valley and foothill grassland between 60 and 400 meters. Serpentinite chaparral, coastal scrub, valley and foothill grassland of the Mt. Hamilton Range between 120 and 460 meters. Maritime chaparral, cismontane woodland, coastal dunes and scrub, sandy valley and foothill grassland between 3 and 450 meters. Sandy or gravelly cismontane woodland openings and coastal dunes and scrub between 3 and 300 meters. Rocky serpentinite cismontane woodland and valley and foothill grassland between 60 and 365 meters. Mesic cismontane woodland, alkaline valley and foothill grassland, vernal pools between 0 and 470 meters. Perennial hemiparasitic forb, blooming between April and June. Evergreen shrub, blooming between January and March. Annual forb, blooming between April and June. Annual forb, blooming between April and September. Perennial forb, blooming between April and June. Annual forb, blooming between March and June. Some potential habitat at Anderson Dam; two known occurrences in the County are located on nearby Coyote Ridge. Documented occurrence at Anderson Dam. Not likely to occur within the project areas due to lack of suitable habitat. Not known from Santa Clara County. Not likely to occur within the project areas. Taxon is extirpated from Santa Clara County. Known from only two historic, non-specific occurrences in late 1800 s. Documented occurrences at Almaden and Coyote dams; suitable habitat present at Anderson, Calero Main, and Chesbro dams due to adjacent serpentine soils. Not likely to occur within the project areas. Known from only one County occurrence in east San Jose which is now extirpated. June 2011 Page 3-14

67 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Species Status Habitat Blooming Period Metcalf Canyon Jewel-flower (Streptanthus albidus ssp. albidus) Showy Indian Clover (Trifolium amoenum) FE, CNPS 1B FE, CNPS 1B Serpentinite valley and foothill grassland between 45 and 800 meters. Coastal bluff scrub and valley and foothill grassland, sometimes on serprentinite, between 5 and 415 meters. Other Special Status Plants Listed by CNPS Franciscan Onion (Allium peninsulare var franciscanum) CNPS 1B Clay cismontane woodland and valley and foothill grassland, often on serpentinite, between 100 and 300 meters. Bent-flowered Fiddleneck (Amsinckia lunaris) Santa Cruz Manzanita (Arctostaphylos andersonii) CNPS 1B CNPS 1B Coastal bluff scrub, cismontane woodland, valley and foothill grassland between 3 and 500 meters. Openings and edges of broadleaved upland forest, chaparral, North Coast coniferous forest between 60 and 700 meters. Annual forb, blooming between April and July. Annual forb, blooming between April and June. Perennial bulbiferous forb, blooming between May and June. Annual forb, blooming between March and June. Evergreen shrub, blooming between November and April. Potential to Occur Within Project Areas Suitable habitat at Anderson Dam; this taxon is known from the Mt. Hamilton foothills south of Metcalf Rd. Not likely to occur within the project areas. Known from only one County occurrence in Gilroy from early 1900 s; taxon is likely extirpated from Santa Clara County. Known from one County occurrence in mid 1900 s; location is in north west side of valley (Page Mill Rd. and Matadero Creek). Suitable habitat present at Anderson, Calero Main, and Chesbro dams due to adjacent serpentine soils. Suitable habitat for this taxon is present at Almaden, Calero Main, Coyote, Guadalupe, Lenihan, Stevens, and Uvas dams. Known from one extant (1998) County occurrence in east San Jose north of Mt. Hamilton Rd. Suitable habitat for this taxon is present at Almaden, Chesbro, Lenihan, and Stevens Creek dams. All occurrences are located in the Santa Cruz Mountains side of SCL Valley. June 2011 Page 3-15

68 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Species Status Habitat Blooming Period Alkali Milk-vetch (Astragalus tener var. tener) San Joaquin Spearscale (Atriplex joaquiniana) Big-scale Balsamroot (Balsamorhiza macrolepis var. macrolepis) Bristly Sedge (Carex comosa) Congdon s Tarplant (Centromadia parryi ssp. congdonii) Mt. Hamilton Thistle (Cirsium fontinale var. campylon) CNPS 1B CNPS 1B CNPS 1B CNPS 2 CNPS 1B CNPS 1B Alkaline playas, adobe clay valley and foothill grassland, and vernal pools between 1 and 60 meters. Alkaline chenopod scrub, meadows and seeps, playas, and valley and foothill grassland between 1 and 320 meters. Chaparral, cismontane woodland, and valley and foothill grassland, sometimes on serpentinite, between 90 and 1400 meters. Coastal prairie, lake margins within marshes and swamps, and valley and foothill grassland between 0 and 425 meters. Alkaline valley and foothill grassland between 1 and 230 meters. Serpentinite chaparral, cismontane woodland, and valley and foothill grassland, in seasonal or perennial drainages on serpentine. Elevation range meters. Annual forb, blooming between March and June. Annual forb, blooming between April and October. Perennial forb, blooming between March and June. Perennial rhizomatous forb, blooming between May and September. Annual forb, blooming between June and November. Perennial herb, blooming between April and August. Potential to Occur Within Project Areas Not likely to occur within the project areas. Bayland species outside of study elevation limits. Taxon is extirpated from Santa Clara County. Not likely to occur within the project areas. Bayland species outside of study elevation limits. Taxon is extirpated from Santa Clara County. Suitable habitat for this taxon is present at Almaden, Anderson, Calero Main, Chesbro, Coyote, Guadalupe, Lenihan, Stevens Creek and Uvas dams. Not likely to occur within the project areas due to lack of suitable habitat. Not known from Santa Clara County; all known occurrences are coastal and/or at low elevation. Not likely to occur within the project areas due to lack of suitable habitat. Known from Laguna Seca, and Stevens Creek (baylands), Sunnyvale Baylands Park, and Alviso. Documented occurrence at Anderson Dam. Occurrences all located in serpentine seeps. Suitable habitat is also present at Calero and Almaden dams. June 2011 Page 3-16

69 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Species Status Habitat Blooming Period San Francisco Collinsia (Collinsia multicolor) Hospital Canyon Larkspur (Delphinium californicum ssp. interius) Western Leatherwood (Dirca occidentalis) Fragrant Fritillary (Fritillaria liliacea) Loma Prieta Hoita (Hoita strobilina) CNPS 1B CNPS 1B CNPS 1B CNPS 1B CNPS 1B Closed-cone coniferous forest and coastal scrub, sometimes on serpentinite, between 30 and 250 meters. Chaparral openings and mesic cismontane woodland between 230 and 1095 meters. Mesic broadleaved upland forest, closed-cone coniferous forest, chaparral, cismontane woodland, and riparian scrub and woodland between 50 and 395 meters. Cismontane woodland, coastal prairie, coastal scrub, and valley and foothill grassland, often on serpentinite, between 3 and 410 meters. Chaparral, cismontane woodland, and riparian woodland, sometimes on mesic serpentinite, between 30 and 600 meters. Annual forb, blooming between March and May. Perennial forb, blooming between April and June. Deciduous shrub, blooming between January and April. Perennial bulbiferous forb, blooming between February and April. Perennial forb, blooming between May and October. Potential to Occur Within Project Areas Documented occurrence at Anderson Reservoir outside of the project area. Suitable habitat for this taxon may occur within the project area at Anderson as well as Almaden, Calero and Coyote dams. Suitable habitat for this taxon is present at Coyote Reservoir. Known from Mt. Diablo State Park and Mt. Hamilton (Historic and current occurrences in Hamilton Range). Suitable habitat for this taxon is present at Stevens Creek and Lenihan dams. One documented occurrence in Palo Alto. Suitable habitat for this taxon is present at Almaden, Anderson, Calero Main, and Chesbro dams. Suitable habitat for this taxon is present at Almaden, Anderson, Calero Main, Chesbro, Coyote, Guadalupe, Lenihan, Stevens Creek and Uvas dams. June 2011 Page 3-17

70 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Species Status Habitat Blooming Period Smooth Lessingia (Lessingia micradenia var. glabrata) Arcuate Bush Mallow (Malacothamnus arcuatus) Hall s Bush Mallow (Malacothamnus hallii) Robust Monardella (Monardella villosa ssp. globosa) Hairless Popcorn Flower (Plagiobothrys glaber) Maple-leaved Checkerbloom (Sidalcea malachroides) CNPS 1B CNPS 1B CNPS 1B CNPS 1B CNPS 1A CNPS 1B Serpentinite chaparral and cismontane woodland, often along roadsides, between 120 and 420 meters. Chaparral between 15 and 355 meters. Chaparral and coastal scrub between 10 and 760 meters. Chaparral openings, cismontane woodland, and coastal scrub between 100 and 915 meters. Alkaline meadows and seeps, and coastal salt marshes and swamps between 15 and 180 meters. Broadleaved upland forest, coastal prairie and scrub, and North Coast coniferous forest, often in disturbed areas, between 2 and 700 meters. Annual forb, blooming between July and November. Evergreen shrub, blooming between April and September. Evergreen shrub, blooming between May and September. Perennial rhizomatous forb, blooming between June and July. Annual forb, blooming between March and May. Perennial forb, blooming between April and August. Potential to Occur Within Project Areas Documented occurrences at Almaden, Anderson, Calero Main, and Coyote dams. Documented occurrences at Calero and Chesbro Reservoirs. Need to resolve taxonomy with M. hallii. Malacothamnus arcuatus is not currently recognized as a species. Documented occurrences at Anderson and Calero Reservoirs. At Calero, occurs on the dam face. Need to resolve taxonomy with M. arcuatus, which has been documented at Calero and Chesbro Reservoirs. Suitable habitat for this taxon is present at Almaden, Calero Main, Coyote, Guadalupe, Lenihan, Stevens Creek and Uvas dams. Not likely to occur within the project areas. This taxon is presumed extinct. Not likely to occur within the project areas. One historic County occurrence from late 1800 s at Alum Rock. Possible mistaken I.D. Other known occurrences are from coastal counties Monterey and Santa Cruz. June 2011 Page 3-18

71 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-3: Special Status Plant Species Documented Within the Project Vicinity Species Status Habitat Blooming Period Most Beautiful Jewel-flower (Streptanthus albidus ssp. peramoenus) Santa Cruz Clover (Trifolium buckwestiorum) Saline Clover (Trifolium depauperatum var. hydrophilum) Caper-fruited Tropidocarpum (Tropidocarpum capparideum) CNPS 1B CNPS 1B CNPS 1B CNPS 1A Serpentinite chaparral, cismontane woodland, and valley and foothill grasslands between 120 and 1000 meters. Broadleaved upland forest, cismontane woodland, and coastal prairie between 105 and 610 meters. Marshes and swamps, mesic/alkaline valley and foothill grassland, and vernal pools between 0 and 300 meters. Alkaline hills within valley and foothill grassland between 1 and 455 meters. Annual forb, blooming between April and June. Annual forb, blooming between April and October. Annual forb, blooming between April and June. Annual forb, blooming between March and April. STATUS CODES FE Federally Endangered CE California Endangered FT Federally Threatened CT California Threatened FPE Federally Endangered (Proposed) CR California Rare FC Federal Candidate CP California Protected CSC California Species of Special Concern (FSC were not included in table due to their lack of regulatory status) Potential to Occur Within Project Areas Documented occurrences at Almaden, Anderson, Chesbro, and Coyote dams. Suitable habitat for this taxon is present at Calero Main dam. Not likely to occur within the project areas due to lack of suitable habitat. Not known from Santa Clara County; Other known occurrences are from coastal counties Monterey and Santa Cruz. Not likely to occur within the project areas due to lack of suitable habitat. Not known from Santa Clara County. Habitat is coastal alkaline grassland. Not likely to occur within the project areas. This taxon is presumed extinct. CNPS California Native Plant Society Listing 1A Plants Presumed Extinct in California 1B Plants Rare, Threatened, or Endangered in California and elsewhere 2 Plants Rare, Threatened, or Endangered in California, but more common elsewhere 3 Plants about which we need more info- a review list 4 Plants of limited distribution a watch list The Jepson Manual (1993) treated Malacothamnus arcuatus and M. hallii as synonyms of M. fasciculatus. However, at the time of printing this document, there is a proposed revision to the genus Malacothamnus that does not recognize M. arcuatus in California, but does distinguish M. hallii from M. fasciculatus (Bodo Slotta 2004). See discussion below under Hall s Bush Mallow for further explanation SOURCE: CDFG 2010; CNPS 2010 June 2011 Page 3-19

72 Section 3.2 Vegetation and Habitat CHAPTER 3 Species extirpated from the County, species known to be extinct, species with range elevation or habitat restrictions, and species without suitable habitat present within the project areas were deemed not likely to be impacted by the proposed project activities and not likely to occur within the project areas. Species with some potential for occurrence within the project areas (such as those with suitable habitat) were targeted for pre-project surveys to establish baseline data for analysis of impacts. These data will be updated periodically throughout the life of the project. SPECIAL STATUS PLANT SURVEY RESULTS ( ; LIMITED UPDATES ) Protocol-level surveys were conducted within the project areas in 2006 and These baseline surveys identified populations of special status plant species within the more natural habitats surrounding the dams at Almaden, Anderson, Calero Main, Chesbro, and Coyote dams (Figure Set III-2 in Appendix III). The results of the surveys are shown in Table Some of these populations were previously known occurrences while others are newly documented through this survey effort. Limited survey updates were conducted in as well, with a new occurrence documented for Malacothamnus hallii at Calero Main Dam in Table 3.2-4: Special Status Plant Occurrence Information 2006/2008 Surveys Location 1 Plant Species Approximate Number of Individuals per Population within ARME 2 Approximate Number of Individuals Beyond ARME, but Still Within the Project Total Population Size (ARME + APE) in Project Area Area 2 Almaden Dam Most beautiful jewelflower Santa Clara Valley dudleya Smooth lessingia Anderson Dam Hall s bush mallow Coyote ceanothus (mature shrubs) 50 2,950 3,000 (seedlings north of spillway) Most beautiful jewelflower Mt. Hamilton thistle Smooth lessingia 650 5,150 5,800 Calero Main Dam Smooth lessingia Arcuate bush mallow Hall s Bush mallow June 2011 Page 3-20

73 Section 3.2 Vegetation and Habitat CHAPTER 3 Table 3.2-4: Special Status Plant Occurrence Information 2006/2008 Surveys Location 1 Plant Species Approximate Number of Individuals per Population within ARME 2 Approximate Number of Individuals Beyond ARME, but Still Within the Project Total Population Size (ARME + APE) in Project Area Area 2 Chesbro Dam Arcuate bush mallow Most beautiful jewelflower Smooth lessingia 0 3,600 3,600 Coyote Dam Santa Clara Valley dudleya Most beautiful jewelflower Notes: 1 Each dam had one population of a given species. 2 Number of individuals in population are approximate due to annual fluctuations in population dynamics of annual plants. 3 Malacothamnus arcuatus underwent a recent taxonomic revision and is not currently recognized. Occurrences at Calero and Chesbro dams should be re-examined in light of the taxonomic revision to determine species identification. SPECIAL STATUS PLANT SPECIES OBSERVED IN THE PROJECT AREAS IN THE SURVEYS COYOTE CEANOTHUS (CEANOTHUS FERRISAE) A large population of the federally endangered Coyote ceanothus was confirmed at Anderson Dam and comprised approximately 3,000 seedlings and 550 mature shrubs when surveyed in 2006 (Table 3.2-4). The seedlings were observed regenerating north of the spillway, on a steep slope that burned in The mature shrubs were observed north of the spillway pool and between the dam face and spillway, with a single shrub occurring near the boat launch ramp. Coyote ceanothus is an erect evergreen shrub of the buckthorn family (Rhamnaceae). It grows up to 2 meters high, with long stiff divergent branches. Twigs are round, smooth and rusty-puberulent, becoming gray with age. Its leaves are opposite, less than 3.2 cm, round to broadly elliptic, dark green and hairless on the upper surface, and lighter green with minute hairs below. Leaf margins have short teeth above the middle or sometimes no teeth at all. The leaf base is abruptly tapered or rounded. Small white flowers bloom from January to March. They are borne in clusters 1.3 to 2.6 cm long. The seed capsules are 7 to 9 mm in width and have three conspicuous apical horns (protuberances situated at the tip) (Hickman 1993; USFWS 1998). Known from only three occurrences on dry serpentine slopes in chaparral and valley and foothill grassland below 1,000 feet in southern Santa Clara County (CDFG 2010), this species is restricted to serpentine soils and is extremely June 2011 Page 3-21

74 Section 3.2 Vegetation and Habitat CHAPTER 3 rare. Existing populations of Coyote ceanothus are composed primarily of mature and senescent individuals with little evidence of seedling recruitment (USFWS 1998), with the exception of the occurrence above Anderson Dam. The germination ecology of many ceanothus species includes an adaptation to remain dormant for long periods in litter and soil seed banks with germination after wildfires (Young and Young 1992). Germination trials conducted using various heat and disturbance treatments suggest that Coyote ceanothus seeds do not require fire for germination (Freas 1993); however, despite results of germination trials, only very limited recruitment has been observed in nature in the absence of fire (Hillman personal observation 2004). These include seedlings that were observed following a 1992 fire in Kirby Canyon (USFWS 1998), as well as thousands of seedlings that emerged after a 2003 fire on slopes north of the spillway at Anderson Dam (Hillman personal observation). Ceanothus experts feel that maintenance of a healthy population of Coyote ceanothus that includes young shrubs requires some prescription burning (USFWS 1998). SANTA CLARA VALLEY DUDLEYA (DUDLEYA SETCHELLII) A population of the federally endangered Santa Clara Valley dudleya was documented on the steep serpentinite cliff across Hicks Road at Almaden Dam (approximately 35 individuals; Table 3.2-4). Another population was found along a steep slope above the spillway at Coyote Dam (approximately 52 individuals). Santa Clara Valley Dudleya is a low-growing perennial of the stonecrop family (Crassulaceae). Its fleshy leaves are oblong triangular, 3 to 8 cm long and 7 to 15 mm wide. Two or three flowering stems grow to heights of 5 to 20 cm in mid- to late spring. Flowers bloom in May and June with pale yellow petals 8 to 13 mm long (Hickman 1993; USFWS 1998). Santa Clara Valley dudleya is found only in the Coyote Valley area of Santa Clara County, from San Jose south about 30 kilometers to San Martin (McCarten 1993). It is restricted to rocky outcrops within serpentine grasslands at elevations between 120 and 300 meters. Santa Clara Valley dudleya produces wind dispersed seeds (McCarten 1993). The species can also reproduce vegetatively by forming rosettes that can separate from the parent plant or remain attached The roots of Santa Clara Valley dudleya are up to 15 cm long and often extend into rock crevices of the serpentine outcrops (McCarten 1993). McCarten studied germination and survivorship of this species at the Kirby Canyon Landfill in Santa Clara County and found survivorship was generally less than 5 percent on both natural and created habitats. He suggested that the primary cause of low survival is the limited number of rock crevices with enough soil to provide the necessary nutrient and moisture conditions. Individual plants of this species may live for approximately 10 years (USFWS 1998). June 2011 Page 3-22

75 Section 3.2 Vegetation and Habitat CHAPTER 3 MT. HAMILTON THISTLE (CIRSIUM FONTINALE VAR. CAMPYLON) The population of Mt. Hamilton thistle at Anderson Dam is located along the edge of the wetlands below the concrete spillway and in a seep on the adjacent slope. During the surveys, the population was mapped at approximately 515 individuals (Table 3.2-4). The majority of the population observed was located within the seep along a steep escarpment north of the spillway pool. However, a single plant was observed above the concrete spillway and four individuals were observed near the base of the spillway waterfall along the project area s western boundary. In the past years, the majority of the population has been located along the edges of the creek in the wetlands below the concrete spillway and in the seep on the slope (Hillman personal observation 2008). SMOOTH LESSINGIA (LESSINGIA MICRADENIA VAR. GLABRATA) Suitable habitat for this species has been mapped at Almaden, Anderson, Calero Main, and Chesbro dams (Table 3.2-2). Large populations of smooth lessingia were observed at Almaden (approximately 30 individuals within the project boundaries, with an added 750 individuals within 100 feet of the boundary), Anderson (approximately 5,800 individuals), Calero Main (approximately 175 individuals), and Chesbro dams (approximately 3,600 individuals; Table 3.2-4). The population at Almaden Dam was growing on a level serpentine ridge above Hicks Road. The populations at Anderson Dam were scattered along the northern and southern slopes of the spillway pool. Calero Main Dam supported only one population of smooth lessingia in a disturbed area east of the dam face. Individuals observed at Chesbro Dam were restricted to the southern slope of the spillway and spillway pool. BUSH MALLOWS (MALACOTHAMNUS ARCUATUS AND M. HALLII) Suitable habitat for Malacothamnus spp. has been mapped at Almaden, Anderson, Calero Main, Chesbro, and Lenihan dams (Table 3.2-2). Shrubs were not identified at Almaden and Lenihan dams during the 2006/2007 surveys (Table 3.2-4). Arcuate bush mallows were observed within the project boundaries of Calero Main Dam (3 shrubs) and along the creek downstream from the outlet and Chesbro (2 shrubs) Dam on the slope north of the spillway pool. A single previously documented Hall s bush mallow was observed along a roadway at Anderson Dam, and two individuals were documented on the Calero Dam face (Hillman 2008). Malacothamnus arcuatus underwent a recent taxonomic revision and is not currently recognized (Slotta 2004). Under the proposed revision to the genus Malacothamnus, shrubs identified as the arcuate bush mallow would likely be classified as either the protected Hall s bush mallow or the common chaparral mallow (Malacothamnus fasciculatus). If the arcuate bush mallow is reclassified as the protected species, the District will treat accordingly. June 2011 Page 3-23

76 Section 3.2 Vegetation and Habitat CHAPTER 3 MOST BEAUTIFUL JEWEL-FLOWER (STREPTANTHUS ALBIDUS SSP. PERAMOENUS) Suitable habitat for this species has been mapped at Almaden, Anderson, Calero Main, Chesbro, and Coyote dams (Table 3.2-2). This species was not observed at Calero Main Dam during the 2006/2007 surveys. Populations of the most beautiful jewel-flower were documented along the serpentine ridge above Hicks Road at Almaden Dam (approximately 4 individuals), above the spillway at Anderson Dam (approximately 13 individuals), within the manzanita chaparral east of the dam face at Chesbro Dam (approximately 500 individuals), and a single individual was observed along the steep slope above the spillway at Coyote Dam (Table 3.2-4) IMPACTS AND MITIGATION MEASURES The DMP includes over 65 activities that are performed as either routine or corrective maintenance. These activities are divided into 14 categories of activities under three main types of activities, as explained in Section 2.5. Many of the program activities have the potential to have an impact on sensitive plants and natural communities if those activities are located in areas where sensitive resources occur. Wherever possible, best management practices such as avoidance will be employed to reduce or eliminate a significant impact. Where impacts cannot be avoided, mitigation measures will be utilized to reduce the impact to a less than significant level Significance Criteria For the purposes of this analysis, an impact was considered to be significant and to require mitigation if it would result in a: Substantial adverse effect, either directly or through habitat modifications, on any plant species identified as a candidate, sensitive, or special status species in local or regional plans, policies or regulations, or by the California Department of Fish and Game or the U.S. Fish and Wildlife Service Substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies or regulations or by the California Department of Fish and Game or U.S. Fish and Wildlife Service Substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act, regulated waters including wetlands and open waters; and state-protected wetlands Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance Conflict with the provisions of an adopted Habitat Conservation Plan, or other approved local, regional, or state habitat conservation plan June 2011 Page 3-24

77 Section 3.2 Vegetation and Habitat CHAPTER Overview Over the life of the DMP in the project area, it is estimated that 85% of the total project impacts will occur within the ARME and 15% of the impacts will occur in the project area outside the ARME. Because the ARME is considered to be a built and thus maintained environment, any plant occurrences (with the possible exception of grasses) within this area will most likely be removed as a regular part of dam maintenance. Wetlands, riparian, serpentine other sensitive habitat will similarly be permanently altered or removed within the ARME. The geographical extent of the ARME is shown in Figure Set III-1 in Appendix III; due to the unpredictability of some of the activities (e.g., seismic exploration) it is not known exactly where beyond the ARME additional impacts in the APE will occur. For purpose of analysis of impacts and mitigation for special status plant species, the basic resource units are populations of individual species of plants. Since plant populations cross over the ARME boundaries, the estimates of impact within ARME and outside (85% and 15% respectively) do not apply. Thus, in the analysis of special status plants the entire project area will be seen as a uniform potential impact area because of the distribution of plant populations. In the discussion of impacts and mitigation measures below, the sensitive plant species have been grouped together for impact assessment of each of DMP activity; while impacts to sensitive natural communities are discussed separately for each DMP activity. The reason for this organizational difference is the ease in evaluating impacts to sensitive plants as a collective impact since the majority of special status, or sensitive plant species are located on serpentine soils. Impacts to sensitive natural communities are evaluated for each community because impacts from activities may, and likely will, be different depending on whether the community is aquatic or terrestrial. As each potential impact is discussed there is reference to BMPs and mitigation measures that would be implemented to reduce the significance level of the impact. Since many of the BMPs and mitigation measures serve multiple purposes, it would not be practical to describe each in its entirety every time it is mentioned. Thus, mitigation measures are briefly summarized the first time they are mentioned, and listed in their entirety at the end of this chapter in section Similarly BMPs are also listed in section and described in full detail in Appendix V Impacts to Sensitive Plants 7 Vegetation surveys conducted between 2006 and 2008 at the nine project sites deemed to have suitable habitat for special status plant species identified populations of sensitive plants within the project areas at Almaden, Anderson, Calero Main, Chesbro, and Coyote dams (Table 3.2-4; Figure set III-4 in Appendix III). Botanical surveys conducted in 2009 and 2010 by H.T. Harvey & Associates, which were restricted to the dam faces, did not yield any new occurrence information. Population size is likely to fluctuate yearly, particularly for annual species; therefore, for impact analysis, the number of populations, number of individuals and amount of suitable habitat are all important factors in evaluating impacts to sensitive plants. 7 The term Sensitive Plant is used interchangeably with Special Status Plant June 2011 Page 3-25

78 Section 3.2 Vegetation and Habitat CHAPTER 3 A summary of sensitive plant occurrences by watershed (Table 3.2-5) indicates that a total of four populations of smooth lessingia and four populations of most beautiful jewelflower occurred within the project impact area. Populations of most beautiful jewelflower were found in all watersheds, while Coyote ceanothus and Mt. Hamilton thistle were found in only one watershed, at Anderson Dam. Santa Clara Valley dudleya were found in both the Guadalupe and Coyote watersheds, but not in the Uvas/Llagas watershed. The largest plant populations were Coyote ceanothus and smooth lessingia, found in the Coyote watershed. Table 3.2-5: Summary of Rare Plant Occurrences and Potential Impacts by Watershed Watershed Coyote Watershed (Anderson and Coyote dams) Guadalupe Watershed (Almaden and Calero Main dams) Uvas/Llagas Watershed (Chesbro Dam) Species Number of Populations & Individuals Within ARME 1,2 Number of Populations & Individuals Beyond ARME, but Still Within the Project Area (acres) 1,2 Total Number of Populations & Individuals (ARME + APE, in acres) 1,2 Coyote ceanothus 1(60) 1(3,490) 1(3,550) Santa Clara Valley dudleya 1(15) 1(37) 1(52) Most beautiful jewelflower 0 2(14) 2(14) Hall s bush mallow 0 1(1) 1(1) Smooth lessingia 1(650) 1(5,150) 1(5,800) Mt. Hamilton thistle 1(509) 1(6) 1(515) Santa Clara Valley dudleya 0 1(35) 1(35) Most beautiful jewelflower 0 1(4) 1(4) Smooth lessingia 0 2(205) 2(205) Hall s bush mallow 1(2) 0 1(2) Arcuate bush mallow 3 0 1(1) 1(1) Most beautiful jewelflower 0 1(500) 1(500) Smooth lessingia 0 1(3,600) 1(3,600) Arcuate bush mallow 3 0 1(2) 1(2) All Watersheds Total Coyote ceanothus 1(60) 1(3,490) 1(3,550) Santa Clara Valley dudleya 1(15) 2(72) 2(87) Most beautiful jewelflower 0 4(518) 4(518) Smooth lessingia 1(650) 4(8,955) 4(9,605) Hall s bush mallow 1(2) 1(1) 2(3) Arcuate bush mallow 3 0 2(3) 2(3) Mt. Hamilton thistle 1(509) 1(6) 1(515) Notes: 1 Number of individuals in parentheses follows number of populations. Population size is based on surveys. 2 Number of individuals in a population is approximate, especially for annual plants. 3 Malacothamnus arcuatus underwent a recent taxonomic revision and is not currently recognized. Occurrences at Calero and Chesbro dams should be re-examined in light of the taxonomic revision to determine species identification. June 2011 Page 3-26

79 Section 3.2 Vegetation and Habitat CHAPTER 3 Wherever applicable and feasible, best management practices such as avoidance will be employed to reduce or eliminate a significant impact (See BMPs BI-10, BI-11, BI-12, and BI-13). Where impacts cannot be avoided, compensatory mitigation measure MM Vegetation-2 will be utilized to reduce the impact to a less than significant level Potential impacts resulting from project activities are discussed further below. SURFACES WORK AND/OR EARTHWORK Surfaces work that could affect sensitive plants includes vegetation management, burrowing rodent control, erosion control, bank stabilization and embankment repairs, access road and boat ramp repairs, and trash and debris removal. All of the surfaces work identified in the program has the potential to have a significant impact on sensitive plants if those activities are located in areas where sensitive plants occur. VEGETATION MANAGEMENT Vegetation management includes several methods of control, including mechanical removal with equipment such as mowers, hand removal with saws, shovels, etc.; use of livestock such as goats for grazing; or use of herbicides. Significant impacts could include alteration of habitat and/or direct damage and mortality to individuals or special status plant populations from mechanical, physical, or chemical removal of vegetation. BURROWING RODENT CONTROL Rodent control includes the destruction of rodent burrows on all dam facilities where burrows are present. Sensitive vegetation could be directly impacted by burrow filling and compaction activities, which involve disturbance of the soil surface, the collapse and filling of burrows, and subsequent soil compaction. Significant impacts could include direct removal of vegetation to access and remove burrows, or compaction of soil and damage to plant roots. Any soil disturbance where populations or individual plants are found could result in a temporary or permanent impact. EROSION CONTROL, BANK STABILIZATION, AND EMBANKMENT REPAIRS Special status plants could also be impacted when the ground is disturbed during erosion control, bank stabilization, and embankment repair activities. Ground disturbance in areas containing special status plants could result in direct removal of plants, compaction of soil and damage to plant roots, crushing of plants, etc. Erosion control and bank stabilization could include the placement of rock riprap or concrete sandbags within the spill pool and plunge pool basins at the base of the outlet structure and/or the spillway. Erosion control could also occur anywhere along the dam face or surrounding areas where erosion is evident. Embankment repairs would include repairs to upland banks, primarily damage identified on the dam face or damage resulting from an earthquake, slump, etc., in other areas within the project boundaries. Rills and gullies on the dam face can be typically repaired through excavation (to June 2011 Page 3-27

80 Section 3.2 Vegetation and Habitat CHAPTER 3 create a proper work space), filling and compaction. In some cases the method would be track walking, which involves tilling the entire dam face surface. ACCESS ROAD AND BOAT RAMP REPAIRS Access road repairs could include grading, laying gravel, widening, fixing erosion, and implementing measures to stabilize access roads. Some species such as smooth lessingia and most beautiful jewelflower can occur along road cuts and even on access roads as these species tend to occupy disturbed, open areas. If special status plant species occur along an access road that requires maintenance, the population or individual plants may be directly impacted. Boat ramp repairs (at Almaden and Guadalupe dams) are not likely to affect special status plant species or because the ramps are located in the reservoirs and on the disturbed crest of the dam; however, it is possible that impacts could be similar to access road repairs if plants are found there. TRASH AND DEBRIS REMOVAL Debris and trash removal would occur most commonly either on dry, ruderal habitat adjacent to existing facilities, within concrete spillways, or along the reservoir shorelines. Trash and debris removal includes picking up small waste, but may also include larger debris. Large woody debris may be hauled off site or crushed on-site. If woody debris is crushed on-site, it would be first piled in a disturbed, ruderal area prior to crushing in order to avoid placement of brush in areas containing special status plants. No woody debris would be crushed on top of native vegetation or living woody shrubs or trees MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures includes work on any built features and/or structures at the dam facilities. Maintenance of certain features, such as the inlet structure, inlet/outlet valves, hydraulic lines, and/or fish screens occurs on the upstream dam face of the dams, either underwater or during reservoir dewatering. Maintenance of the outlet structure and outlet pipe would occur on the downstream face of the dam and in the outlet pipe or tunnel. Other appurtenant structure work could include concrete repairs and repairs to minor structures such as piezometers, survey monuments, the dam spillway, blockhouse, telemetry and other electrical equipment, etc. Maintenance of the majority of appurtenant structures is not likely to impact special status plant species. However, these activities have the potential to have a significant impact on sensitive plants if the activities are located in areas where sensitive plants occur. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring are performed to meet the requirements of the DSOD and FERC to ensure continued safe delivery of water and flood protection. Inspections and monitoring are typically minimally intrusive activities. June 2011 Page 3-28

81 Section 3.2 Vegetation and Habitat CHAPTER 3 Exploratory work could involve ground disturbance and trenching or boring anywhere within the defined project areas, such as for geotechnical investigations or as otherwise directed by the DSOD. These activities have the potential to have a significant impact on sensitive plants if the activities are located in areas where sensitive plants occur. RESERVOIR DEWATERING OVERVIEW Some elements of the DMP will require reservoir dewatering so that maintenance can occur in the area in or behind the dam. Reservoir dewatering will involve complete draining of the reservoir. For further details on dewatering please see Chapter 2. For the purposes of this DMP EIR, a programmatic analysis will be presented using the information that is available at the time of publication. While some information regarding the effects and potential mitigation measures for reservoir dewatering for north county reservoirs is available at this time, the same level of detail is not available to address impacts and mitigation for dewatering the two south county reservoirs (Chesbro and Uvas). Accordingly, impacts of reservoir dewatering at each dam will be further evaluated in a project-level CEQA analysis before the dewatering occurs. POTENTIAL IMPACTS When reservoirs are dewatered for necessary dam maintenance, the dewatering creates (a) sustained high flows as the reservoir is drained and (b) sustained very low flows when the reservoir is empty or refilling. These changes in flow have the potential to affect two natural communities associated with channels downstream from the dams (freshwater marsh and riparian woodland). The potential effects on freshwater marsh and riparian woodland are described below. Potential Impact 1: Effects of Flows Needed to Drain the Reservoirs on Sensitive Plant Communities In order to prepare the dam for maintenance during the summer and fall, water would need to be released during spring and summer at higher rates than normal. These consistently higher flows during dewatering could adversely affect riparian and wetland vegetation due to scouring or inundation. It is estimated that steady-state flows greater than 50% of winter baseflow could have significant effects on vegetation in the channel, and that the length of channel affected by flows 50% greater than winter base flows would be approximately 26 miles for Coyote Creek. Stevens and Guadalupe watersheds would not be affected, because the reservoirs in those watersheds are small and would not be subject to flows greater than 50% of winter baseflows. Dewatering Chesbro and Uvas reservoirs may cause similar impacts, although June 2011 Page 3-29

82 Section 3.2 Vegetation and Habitat CHAPTER 3 insufficient information is available to determine the full extent of the potential effects. Potential Impact 2: Effects of Lower Than Normal Flows on Sensitive Plant Communities When the reservoirs are dewatered, the main source of flow to the downstream channel would be removed, although tributaries above and below the dams would still supply a minimal amount of flow. Bypass pump over will be typically needed to ensure a dry work area, so some water will normally be passed over the dam as well. Thus, the ability of downstream channels to support riparian and wetland vegetation during the period of maintenance and while the reservoirs are refilling would be significantly reduced. These events could stress riparian and wetland vegetation and in extreme cases, vegetation health could decline to the point where it would die. The approximate length of channel affected by lower than normal flows under average conditions is as follows: Coyote Creek, 11 miles; Guadalupe Watershed, 17 miles, and Stevens Creek, 4 miles. Insufficient information is available at this time to determine channel length impacts from dewatering Chesbro and Uvas reservoirs. Potential Impact 3: Impacts to Special Status Plants Impacts from reservoir dewatering activities may occur to special status or listed plant species, where those plants occur in or adjacent to channels. Impacts to special status or listed plants would likely be similar to wetland and riparian vegetation impacts. Higher than average flows could scour out plants, while lower than average flows or a complete dry back could result in plant die off due to lack of water. For example, a population of Mt. Hamilton thistle (Cirsium fontinale var. campylon), an obligate wetland species, is known to occur in the spillway of Anderson dam. Flow release would not occur over the spillway, so no scouring of those plants is expected to occur from this activity. However, flows from the seepage monitoring weirs that keep the spillway channel below the weir inundated, could cease during a dewatering event and plants could die due to lack of water. It is unknown whether flows would cease entirely when the reservoir is dewatered. MM General-1,-2 and -3 provide for project-level review and consultation, ramping, supplemental water and protective measures to address potential impacts to vegetation downstream of dams from dewatering activities. MM General-1 and -2 ensure that prior to approval of any dewatering, a project-level environmental review will be conducted to analyze impacts and mitigation measures for individual reservoir dewatering projects and that the District will coordinate with the resource agencies. MM General-3 requires a dewatering plan to be prepared before each dewatering event; the plan would include provisions for ramping and supplemental water so as to reduce or avoid significant impacts. June 2011 Page 3-30

83 Section 3.2 Vegetation and Habitat CHAPTER 3 SUMMARY These measures are expected to reduce the potential effects of reservoir dewatering on downstream vegetation. It is expected that dewatering for maintenance would continue for one season only. Supplemental water sources are expected to provide sufficient flows to maintain a normal water regime in downstream channels, and thereby avoid impacts on downstream vegetation at all locations where available; at those locations where supplemental water sources are expected to be unavailable (Uvas, Chesbro, Guadalupe and Almaden dams) the potential for effects on downstream vegetation here is higher than for other dams. However, in addition to the flow supplied by bypassing the streams above the reservoir, the corresponding watersheds have tributaries supplying additional water downstream of the bypassed water which will continue to provide flows despite dewatering upstream. Moreover, to the extent impacts to vegetation are significant and cannot be avoided, compensatory mitigation as required by MM Vegetation-6 would reduce these impacts to less than significant by requiring monitoring of vegetation potentially affected by dewatering at these four locations, and if necessary, ensuring that affected vegetation is replaced. Table summarizes the impact analysis and compensatory mitigation for unavoidable impacts to special status plant species known to occur within the project area; mitigation for impacts to special status plants will be implemented through MM Vegetation-2, described fully at the end of this chapter. The compensation mitigation for coyote ceanothus is different than that of the other covered plant species due to its extreme rarity and expected impacts from DMP activities. The District will implement MM General-4 to avoid or minimize negative impacts on sensitive plants from trash and debris removal activities. June 2011 Page 3-31

84 Section 3.2 Vegetation and Habitat CHAPTER 3 Species Coyote ceanothus Table 3.2-6: Summary of Analysis of Impacts and Mitigation to Special Status Plant Populations Impact and Mitigation Analysis A portion of one of the three existing Coyote ceanothus populations is expected to be impacted by DMP activities (approx. 60 individuals located within the ARME at Anderson Dam). Part of this occurrence is also found outside the ARME within the APE (approx. 3,490 individuals); this portion of the population could be impacted by other DMP activities that occur anywhere in the APE. The mitigation strategy for Coyote ceanothus is generally similar to that of the other covered plant species. Prior to impacting the Anderson Dam population, one known occurrence (one population) of Coyote ceanothus will be protected or created. (MM Vegetation-2) Santa Clara Valley dudleya Mt. Hamilton thistle Smooth Lessingia The project would have a less than significant impact on Coyote ceanothus with mitigation outlined above and in the Santa Clara Valley Habitat Plan. Project activities could impact a portion of two populations of Santa Clara Valley dudleya as currently mapped within DMP project areas. A portion of one population of Santa Clara Valley dudleya would be directly impacted by DMP activities that occur in the ARME at Coyote Dam. Approximately 15 individuals from this population could be impacted. Additionally, some of the remaining 37 individuals that fall within outside the ARME but within the overall project APE at Coyote Dam may be impacted by DMP activities in the future. A separate population of 35 individuals at Almaden Dam may also be impacted. The amount of impacts to both populations is not likely to be greater than 35%of each population size. Implementation of the DMP would not have a significant impact on Santa Clara Valley dudleya with mitigation (MM Vegetation-2). Approximately 500 individuals of Mt. Hamilton thistle would be impacted due to proximity within the ARME at Anderson Dam in the natural spillway section, which constitutes nearly the entire population. Implementation of the DMP would not have a significant impact on Mount Hamilton thistle with mitigation (MM Vegetation-2). A portion of four populations of smooth lessingia could be impacted by DMP activities. Approximately 650 individuals from the population at Anderson Dam would be directly impacted due to location within the ARME (which represents approx. 11% of the Anderson Dam population). Additionally, 30 individuals at Almaden Dam, approximately 5,150 individuals at Anderson Dam, 175 individual at Calero Main Dam, and 3,600 individuals at Chesbro Dam fall within the overall project APE and may be impacted by future DMP activities. The percentage of these populations (outside the ARME) to be affected would likely be fewer than 30%. These numbers are approximate due to annual fluctuations in population dynamics of annual plants such as smooth lessingia. Population size and number would be updated periodically during the lifetime of the DMP. Implementation of the DMP would not have a significant impact on smooth lessingia with mitigation (MM Vegetation-2). June 2011 Page 3-32

85 Section 3.2 Vegetation and Habitat CHAPTER 3 Species Bush mallow Table 3.2-6: Summary of Analysis of Impacts and Mitigation to Special Status Plant Populations Impact and Mitigation Analysis A Malacothamnus sp. identified as arcuate bush mallow was observed within the project boundaries of Calero Main Dam (3 shrubs) and along the creek downstream from the outlet and Chesbro (2 shrubs) Dam on the slope north of the spillway pool. A single previously documented Hall s bush mallow was observed along a roadway at Anderson Dam, and two individuals were documented on the Calero Dam face (Hillman 2008). Malacothamnus arcuatus underwent a recent taxonomic revision and is not currently recognized. Occurrences at Calero and Chesbro dams should be re-examined in light of the taxonomic revision to determine species identification. Most beautiful jewel flower Implementation of the DMP would not have a significant impact on Hall s bush mallow with mitigation (MM Vegetation-2). A portion of four populations of most beautiful jewel flower may be impacted by covered activities under the DMP. Populations of most beautiful jewel flower occur at Almaden, Anderson, Coyote, and Chesbro dams within the overall project APE outside the ARME. Implementation of the DMP would not have a significant impact on most beautiful jewel flower with mitigation (MM Vegetation-2). Additional populations of special status plant species could be found within the project area in the future due to the presence of suitable habitat within the APE (Table 3.2-7). Therefore special status plant surveys will be conducted periodically throughout the life of the DMP to update existing information, locate new populations and to document population dynamics within potential impact areas (MM Vegetation-1). If new populations are discovered within an area to be impacted by DMP activities and cannot be avoided, compensation mitigation shall also be required per MM Vegetation Impacts to Sensitive Natural Communities Sensitive natural communities that could be impacted by dam maintenance activities occur to varying extent at all the dams (Table 3.2-7; Figure set III-1 in Appendix III) and fall into three general types: natural communities found on serpentine soils, riparian woodlands, and freshwater marsh wetlands. June 2011 Page 3-33

86 Section 3.2 Vegetation and Habitat CHAPTER 3 Location Table 3.2-7: Sensitive Natural Communities Within the Project Area Natural Community Sensitive Habitat Within ARME (acres) Sensitive Habitat beyond ARME, but Still Within the Project Area (acres) Total Sensitive Habitat (ARME + APE, in acres) Almaden Dam Mixed Serpentine Chaparral * 0.06 Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Anderson Dam Northern Coastal 0.21* 19.6* Scrub/Diablan Coastal Scrub Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Calero (Fellows Riparian Woodland, Forest Dike) and Scrub Coastal and Valley Freshwater Marsh Calero Main Dam Mixed Serpentine Chaparral Riparian Woodland, Forest and Scrub Chesbro Dam Mixed Serpentine Chaparral 0.75* 4.60* 5.35 Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Coyote Dam Northern Coastal 0.16* 3.24* 3.40 Scrub/Diablan Coastal Scrub Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Coyote Percolation Riparian Woodland, Forest Dam and Scrub Guadalupe Dam Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Lenihan Dam Northern Coastal Scrub/Diablan Coastal Scrub Riparian Woodland, Forest and Scrub June 2011 Page 3-34

87 Section 3.2 Vegetation and Habitat CHAPTER 3 Location Stevens Creek Dam Uvas Dam Vasona Dam Table 3.2-7: Sensitive Natural Communities Within the Project Area Natural Community Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Coastal and Valley Freshwater Marsh Riparian Woodland, Forest and Scrub Sensitive Habitat Within ARME (acres) Sensitive Habitat beyond ARME, but Still Within the Project Area (acres) Total Sensitive Habitat (ARME + APE, in acres) *Indicates habitat occupied by special status plant species ( botanical surveys). Table summarizes the sensitive natural community occurrences by acreage in each watershed. The ways in which natural communities could be negatively affected by project activities are very similar to potential impacts to special status species. Impacts to sensitive natural communities and habitat could result from any dam maintenance activity that disturbs the soil and associated vegetation. In the built and maintained environment of the ARME, an impact would be considered permanent. Wherever feasible, best management practices such as avoidance will be employed to reduce or eliminate a significant impact. If impacts are unavoidable even with best management practices (BMPs BI-10, BI-11, BI-12, BI-13), compensation for sensitive natural communities within the ARME will be implemented prior to the initiation of the site specific DMP activity by application of MM Vegetation-3, MM Vegetation-4, and MM Vegetation-5. Similar compensation will be based on a pay-as-you-go method for impacts outside the ARME. June 2011 Page 3-35

88 Section 3.2 Vegetation and Habitat CHAPTER 3 Watershed Coyote Watershed (Anderson, Coyote and Coyote Percolation dams) Guadalupe Watershed (Almaden, Calero [Main and Fellows Dike], Guadalupe, Lenihan, and Vasona dams) Stevens Watershed (Stevens Creek Dam) Uvas/Llagas Watershed (Chesbro and Uvas dams) All Watersheds Total Table 3.2-8: Summary of Sensitive Natural Community Potential Impacts by Watershed Natural Community Northern Coastal Scrub/Diablan Coastal Scrub Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Northern Coastal Scrub/Diablan Coastal Scrub Mixed Serpentine Chaparral Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Mixed Serpentine Chaparral Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Northern Coastal Scrub/Diablan Coastal Scrub Mixed Serpentine Chaparral Riparian Woodland, Forest and Scrub Coastal and Valley Freshwater Marsh Sensitive Habitat Within ARME (acres) Sensitive Habitat Beyond ARME, but Still Within the Project Area (acres) Total Sensitive Habitat (ARME + APE, in acres) June 2011 Page 3-36

89 Section 3.2 Vegetation and Habitat CHAPTER SERPENTINE-ASSOCIATED SENSITIVE NATURAL COMMUNITIES 8 The proposed DMP activities could have significant impacts on serpentine-associated vegetation communities and habitat within the DMP area. Table lists the areas of serpentine habitat by dam (Figure set III-1 in Appendix III) and Table summarizes the amount of habitat by watershed. An analysis of vegetation communities within the project area indicated that serpentine vegetation is present at Almaden, Anderson, Calero, Chesbro, Coyote, and Lenihan dams (Table 3.2-7). Serpentine-associated vegetation communities within the project area include northern coastal scrub/diablan coastal scrub and mixed serpentine chaparral. While the majority of serpentine vegetation is found within the additional area outside the ARME, Anderson, Chesbro, Coyote and Lenihan dams do support sensitive serpentine habitat within the known impact area of the ARME. Habitat area ranges from 0.06 acres at Lenihan to 0.75 acres at Chesbro. Serpentine habitat located within the ARME that was occupied by special status plant species ( botanical surveys) occurred at a subset of dams (Anderson, Chesbro and Coyote dams, Table 3.2-7); however, all serpentine-associated habitat was considered suitable for occupancy by special status plant species. By watershed, the Uvas/Llagas watershed has the greatest amount of serpentine habitat that will be impacted by activities in the ARME (0.75 acres of mixed serpentine chaparral; Table 3.2-8). The Coyote watershed dam maintenance projects are projected to impact 0.37 acres of northern coastal scrub/diablan coastal scrub, while the Guadalupe watershed dam maintenance projects are projected to impact 0.06 acres of northern coastal scrub/diablan coastal scrub. In total, the projects are expected to impact 0.43 acres of northern coastal scrub/diablan coastal scrub and 0.75 acres of mixed serpentine chaparral within the ARME (1.18 total acres of serpentine-associated habitat; Table 3.2-8). Impacts to serpentine-associated sensitive natural communities and habitat could result from any dam maintenance activity that disturbs the soil and associated vegetation. This can include impacts to existing populations of sensitive plants as well as the loss of suitable, unoccupied habitat. If impacts are unavoidable even with best management practices (BMPs BI-10, BI-11, BI-12), compensation for all serpentine habitats/sensitive serpentine associated communities within the ARME will be implemented prior to the initiation of the site specific DMP activity, and on a pay-as-you-go basis for impacts outside the ARME (MM Vegetation-3). SURFACES WORK AND/OR EARTHWORK Vegetation Management and Burrowing Rodent Control Vegetation management would mostly occur on dam faces and around appurtenant structures. There is limited serpentine habitat on the dam faces; however, there is habitat located adjacent to the dam faces in the 8 This category includes Mixed Serpentine Chaparral and Northern Coastal Scrub/Diablan Coastal Scrub June 2011 Page 3-37

90 Section 3.2 Vegetation and Habitat CHAPTER 3 groins and on the dam abutments. Removal of serpentine-associated vegetation or repeated disturbance of serpentine habitat would be considered a significant impact. Burrowing rodent control includes use of pesticides and the removal of rodent burrows. These activities are not expected to impact serpentine habitat. Burrows exist in serpentine habitat adjacent to the dam faces; however, the District does not need to implement burrow management in these areas because those burrows do not threaten the integrity of any of the dam facilities. Burrow removal that may occur in areas adjacent the dam faces, such as from following a burrow tunnel from the dam face into the groin or dam abutment, will be conducted in a way that minimizes impacts on adjacent vegetation (BMP BI-12). Access Road and Boat Ramp Repairs Boat ramp repairs are not likely to significantly impact serpentine habitat. Serpentine habitats are absent from the Almaden and Guadalupe dams boat ramps and the immediately surrounding areas. The District is only responsible for boat ramps at these two dams. Access road repairs could impact serpentine habitat if work were to expand beyond the existing roadway. Serpentine habitat could be permanently or temporarily damaged during road grading, improvement of drainage, or stabilization of the roadways. Impacts could also occur due to root compaction from driving over access roads, and/or from tree or shrub trimming to allow maintenance vehicles to pass along the access route. Temporary or permanent damage to serpentine habitat near roadways would be considered a significant impact. In order to reduce or minimize impacts, appropriate BMPs will be employed wherever possible (BMPs BI-10, BI-11, and BI-12). Compensation, as defined in mitigation measure MM Vegetation-3, would reduce impacts to less than significant levels if BMPs cannot be employed effectively. Trash and Debris Removal Trash and debris removal requires removing garbage and other debris from around the dam areas. This activity would not likely have an adverse impact on serpentine habitat. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of the majority of the appurtenant structures is unlikely to impact serpentine communities because the structures are located in a built and maintained environment rather than in areas that contain serpentine habitat. In order to reduce or minimize impacts that may occur, appropriate BMPs will be employed wherever possible (BMPs BI-10, BI-11, and BI-12). Compensation, as defined in mitigation measure MM Vegetation-3, would reduce impacts to less than significant levels if BMPs cannot be employed effectively. June 2011 Page 3-38

91 Section 3.2 Vegetation and Habitat CHAPTER 3 INSPECTIONS, MONITORING, AND EXPLORATORY WORK Exploratory work could involve ground disturbance and trenching or boring anywhere within the defined project areas, such as for geotechnical investigations or as otherwise directed by DSOD and FERC. Exploration could also include access road construction to reach the exploration sites on dam faces or abutments, etc. This work may impact serpentine communities if the trenching or related work is located in these communities. In order to reduce or minimize impacts that may occur, appropriate BMPs will be employed wherever possible (BMPs BI-10, BI-11, and BI-12). Compensation, as defined in mitigation measure MM Vegetation-3, would reduce impacts to less than significant levels if BMPs cannot be employed effectively. RESERVOIR DEWATERING No impacts to serpentine communities or habitat are likely to result from reservoir dewatering because serpentine communities are not generally found within the areas of potential impact RIPARIAN SENSITIVE NATURAL COMMUNITIES Riparian woodland and forest was present at all dams except Uvas Dam (Table 3.2-6). Riparian woodland impacts within the ARME are not projected to exceed 0.25 acres at any dam. Riparian woodland habitat area ranges from 0.04 acres at Vasona Dam, to 0.25 acres at Calero (Fellows Dike) Dam. By watershed, the Guadalupe watershed dam maintenance projects are projected to impact 0.89 acres of riparian woodland, forest and scrub (Table 3.2-7). The Coyote watershed dam maintenance projects are projected to impact 0.24 total acres of riparian woodland, forest and scrub, while the Stevens watershed (Stevens Creek Dam) dam maintenance is projected to impact 0.12 acres. Total watershed impacts to riparian woodland, forest and scrub within the ARME are projected to be 1.32 acres. Impacts to riparian woodland, forest and scrub could result from any dam maintenance activity that disturbs the soil and associated vegetation. Since riparian vegetation and associated habitat is typically found adjacent to stream channels downstream of the dams, erosion control, bank stabilization and embankment repairs are most likely to have a significant impact on this natural community. Impacts to riparian habitat could include permanent removal of habitat for placement of bank stabilization (even if biostabilization methods are used), or disturbance for access to repair areas. Other impacts could include removal of woody vegetation adjacent to spillway pools or in the vicinity of the dam outlets. Reservoir dewatering could affect riparian habitat in the downstream stream channels; these potential impacts and additional mitigation measures are discussed in the Reservoir Dewatering under Section If impacts are unavoidable through best management practices (BI-10, BI-11, BI-12), compensation for all riparian woodland, forest and scrub communities within the ARME will be implemented prior to the initiation of the site specific DMP activity. Impacts to the area outside the ARME but still within the APE will be evaluated and June 2011 Page 3-39

92 Section 3.2 Vegetation and Habitat CHAPTER 3 compensated for on a case-by-case basis as it cannot be projected in advance where the those impacts will occur. The District would mitigate impacts to riparian habitat in a similar manner to the mitigation for sensitive plant species and serpentine habitat. MM Vegetation-4 would be implemented to compensate for unavoidable impacts to riparian habitats prior to site specific DMP activity. MM Vegetation-4 would restore or enhance affected riparian habitat and impacts would be reduced to a less than significant level. SURFACES WORK AND/OR EARTHWORK Vegetation Management and Burrowing Rodent Control Vegetation management would mostly occur on dam faces and around appurtenant structures. There is no riparian habitat on the dam faces; however, some appurtenant structures are located within or adjacent to riparian corridors. Removal of riparian vegetation or repeated disturbance of riparian vegetation would be considered a significant impact. Burrowing rodent control includes use of pesticides and the removal of rodent burrows includes digging and compaction. Burrows are not common in riparian habitat and the District typically does not need to implement burrow management in riparian habitat areas because those burrows do not threaten the integrity of any of the dam facilities. However, it is possible that the District would need to follow and eliminate a burrow that originates from a dam face and continues into riparian habitat. These activities have only a small chance of impacting a minimal amount of riparian habitat. In order to reduce or minimize impacts, appropriate BMPs will be employed wherever applicable and feasible (BI-10, BI-11, and BI-12). If BMPs cannot be employed to avoid impacts to riparian habitat, compensation, as defined in mitigation measure MM Vegetation-4, would be employed to reduce potential impacts to less than significant levels. Access Road and Boat Ramp Repairs Boat ramp repairs are not likely to significantly impact riparian habitat. Riparian habitats are absent from the Almaden and Guadalupe dams boat ramps and the immediately surrounding areas. The District is only responsible for boat ramps at these two dams. Access road repairs could impact riparian habitat if work were to expand beyond the existing roadway. Roadways below several dams are adjacent to riparian habitat. Riparian habitat could be permanently or temporarily damaged during road grading, improvement of drainage, or stabilization of the roadways. Impacts could also occur due to root June 2011 Page 3-40

93 Section 3.2 Vegetation and Habitat CHAPTER 3 compaction from driving over access roads, and/or from tree trimming to allow maintenance vehicles to pass along the access route. Temporary or permanent damage to riparian habitat near roadways would be considered a significant impact. If BMPs cannot be employed to avoid impacts to riparian habitat, compensation, as defined in mitigation measure MM Vegetation-4, would be employed to reduce potential impacts to less than significant levels. Trash and Debris Removal Trash and debris removal requires removing garbage and other debris from around the dam areas. Although it is highly unlikely that this activity would occur in riparian areas, MM General-4 would ensure that that this activity would not negatively impact riparian habitat. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures includes work performed on any existing structures at the dams. Hydraulic line repair, blockhouse repair, concrete repairs, etc., are included in this category. Maintenance of appurtenant structures, particularly shutdown of the inlet/outlet, could significantly impact downstream riparian habitat. There is also a small likelihood that a minimal amount of woody vegetation in the riparian corridor could be impacted during maintenance of structures such as blockhouses or survey monuments. Maintenance activities may require the cessation of flows to access appurtenant structures. Altering flows would cause a significant impact to downstream habitats. For short term maintenance which would otherwise result in a cessation of stream flow, a flow bypass system would be implemented for any shutdown of the inlet/outlet (MM Wildlife-1). Flow bypass would provide an alternative source of water to prevent impacts to the riparian vegetation and habitat. The system would manage flow quantity, temperature, and turbidity within 80% of baseline conditions up to 400 feet downstream of the spillway. Riparian vegetation downstream, however, is not sensitive to slight fluctuations in temperatures (a few degrees) or a reduced flow, as long as the habitat does not dry out. Long term maintenance requiring dewatering of a reservoir is discussed below. MM Vegetation-4 would compensate for riparian habitat impacted by the removal of woody vegetation during maintenance of appurtenant structures. BMP BI-10 and BI-11 reduce impacts associated with tree trimming as it may be required for maintenance of appurtenant structures. MM Wildlife-1 would minimize impacts associated with short-term cessation of releases. June 2011 Page 3-41

94 Section 3.2 Vegetation and Habitat CHAPTER 3 INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring are performed to meet the requirements of the DSOD and FERC as well as to ensure continued safe delivery of water and flood protection. Inspections and monitoring are minimally intrusive activities and thereby would not significantly impact riparian habitat. Exploratory work involving ground disturbances, such as trenching or drilling, would be considered significant if it were to occur in riparian habitat and woody vegetation were impacted. It is not likely that the exploratory work would occur in riparian habitat; however, root systems of trees in nearby riparian areas could be impacted. Implementation of BMPs BI-10 and BI-11, and MM Vegetation-4 would reduce the potential impacts to riparian habitat from exploratory work to a less than significant level. Any tree trimming required for completing inspections, monitoring, or exploratory work would be performed according to the professional recommendation of a certified arborist after evaluation of trees targeted for trimming (BMP BI-10) to prevent any significant damage to riparian trees. RESERVOIR DEWATERING Riparian habitats could be impacted by increased flows and scouring that could cause erosion as well as through reduced water availability and flows once the dewatering is complete. Potential impacts and mitigation related to riparian habitat are discussed under section Wetland Sensitive Natural Communities Coastal and valley freshwater marsh was mapped at the majority of dams within the project area (Table 3.2-6). Federally regulated wetlands and waters are further identified in the wetland delineation (SCVWD 2008). Specifically, freshwater marsh wetlands were present at Almaden Dam, Calero (Fellows Dike), Chesbro Dam, Coyote Dam, Guadalupe Dam, Stevens Creek Dam, and Uvas Dam. A total of 0.19 acres of wetlands are located within the ARME at all dams within the project area (Table 3.2-7). Within the larger APE footprint, a total of 4.19 acres of wetlands occur. While direct impacts to wetlands from project activities are small, (except for the seepage monitoring systems at Calero and Almaden dams which directly affect wetlands; (see Appendix III for biotic maps), wetlands do occur adjacent to areas proposed for vegetation management, and because of their proximity within the ARME, there may be indirect impacts from projected activities. To the extent feasible, direct and indirect impacts on wetlands or open water habitats would be avoided (BI-10, BI-11, BI-12). If impacts to wetlands cannot be avoided, MM Vegetation-5 would provide compensatory mitigation. VEGETATION MANAGEMENT AND BURROWING RODENT CONTROL With the exception of seepage monitoring systems, wetlands typically do not occur within areas proposed for vegetation management activities. Burrowing rodent control would occur in upland areas only. While direct impacts to wetlands from vegetation management and rodent control are not likely, wetlands do occur adjacent June 2011 Page 3-42

95 Section 3.2 Vegetation and Habitat CHAPTER 3 to areas proposed for vegetation management, and because of their proximity within the ARME, there may be indirect impacts from projected activities. To the extent feasible, direct and indirect impacts on wetlands or open water habitats would be avoided (BI-10, BI-11, BI-12). If impacts to wetlands cannot be avoided, MM Vegetation-5 would provide compensatory mitigation. Impacts to water quality are discussed further in Section 3.4 Hydrology and Water Quality. EROSION CONTROL AND BANK STABILIZATION Erosion control and bank stabilization activities could occur within wetlands and open waters downstream of the dams. Impacts such as removal of wetlands or open water habitat would be considered significant and would require compensation mitigation to minimize impacts in accordance with the USACOE no net loss of wetlands policies. Regulated waters most likely to be impacted during the course of the program include: Waters along the banks of the spillway pools Waters downstream of dams where hydrophytic vegetation could be removed and replaced with fill material (such as rock riprap or concrete sandbags) The wetlands at the Almaden and Calero Main dams where the amount of seepage may be altered Potentially designated wetlands on Lenihan Dam For unavoidable impacts to wetlands, MM Vegetation-5 will be employed. No open waters such as reservoirs and streams would be filled for the DMP. Some work and placement of fill may occur below the Ordinary High Water Mark (OHWM) of waterways; however, no loss of open water habitat would occur. Impacts would be limited to the riparian bank vegetation. A breakdown of the quantification of impacts to wetlands is included in Table Impacts for potential seepage projects are included in Table but is discussed under the heading Maintenance of Appurtenant Structures. Reservoir areas within the ARME are not included in Table because this area would not be filled. Open waters that fall within the ARME are not included, as these areas would not be filled. Impacts to wetland habitat and open waters would be considered significant. Areas within the ARME cannot be avoided as disturbance of these areas is necessary to meet DSOD requirements for the safety of the dams (except for areas of the ARME that are in the reservoirs). June 2011 Page 3-43

96 Section 3.2 Vegetation and Habitat CHAPTER 3 The District would mitigate for impacts to seasonal wetlands within the ARME through upfront on-site and/or off-site compensation implementation as included in MM Vegetation-5. Restoration would prevent a net loss of wetlands and would reduce potentially significant impacts to less than significant levels. While lengths of streams may be impacted through the placement of bank hardening and stabilization or other erosion repair, no loss of open waters is anticipated. A Section 404 permit from the USACOE may still be required; however, compensation for impacted riparian habitat would be implemented through mitigation measure MM Vegetation-4. Bank hardening would usually be performed using bioengineered materials, where feasible. ACCESS ROAD AND BOAT RAMP REPAIRS It is unlikely that access road (at all sites except Rinconada Treated Water Reservoir Dam, where aquatic habitat is absent) and boat ramp (at Almaden and Guadalupe dams) repairs would impact wetlands or other regulated waters. Impacts to these waters would be considered significant, however, if road repairs occur in an area adjacent to a regulated water. For example, there is a seasonal wetland at Guadalupe Dam that overflows from the plunge pool, continuing over the access road into Guadalupe Creek. Similarly, the wetland caused by seepage at the base of Almaden Dam is located immediately adjacent to an access road. MM Vegetation-4 and MM Vegetation-5, which provide compensatory mitigation for impacts to riparian and wetland habitats, would reduce the potential impacts to regulated waters from access road and boat ramp repairs to a less than significant level. Additional permits may be required from the appropriate governing agency prior to disturbance; the USACOE and RWQCB regulate impacts below ordinary high water and CDFG regulates impacts below top of bank or within riparian habitat. TRASH AND DEBRIS REMOVAL No regulated waters occur in areas proposed for trash and debris removal; therefore, trash and debris removal would not impact aquatic habitat or wetlands. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures includes work on any built dam features. Maintenance of dam appurtenances, particularly activities that require closing of the inlet/outlet (portal gates, radial gates, etc.), could significantly impact downstream wetlands and open water habitat. Similarly, any other activity on dam features/structures that would occur within regulated waters or wetlands would be considered potentially significant. Seepage monitoring systems would be repaired, updated, or installed in areas that have become wetlands due to existing seepage. For example, installation of a new seepage monitoring system could remove a portion of existing wetlands at Almaden, Calero Main, Calero Auxiliary, and Uvas dams. Compensation mitigation for the loss of wetland habitat would be implemented, as defined in MM Vegetation-5, to reduce potentially significant impacts to wetlands and open waters to less than significant levels. The placement June 2011 Page 3-44

97 Section 3.2 Vegetation and Habitat CHAPTER 3 of seepage monitoring weirs in regulated waters or maintenance on the outlet structures where hydrophytes are dominant could also impact regulated waters. Maintenance activities may require the cessation of flows to access appurtenant structures. Altering flows could cause a significant impact to downstream habitats. A flow bypass system would be implemented for any short term shutdown of the inlet/outlet (MM Wildlife-1) which would otherwise cause a cessation in stream flow. Flow bypass would provide an alternative source of water to prevent impacts to the riparian vegetation and habitat. The system would manage flow quantity, temperature, and turbidity within 80% of baseline conditions up to 400 feet downstream of the spillway. Riparian vegetation downstream, however, is not sensitive to slight fluctuations in temperatures (a few degrees) or a reduced flow, as long as the habitat does not dry out. MM Wildlife-1 also incorporates ramping to smoothly transition between the flow bypass system and normal reservoir levels. The release of water will be ramped up or down such that the flow rate to receiving waters is gradual and does not cause scouring of the channel bed. (Maintenance requiring reservoir dewatering is discussed below.) MM Vegetation-5 and MM-Wildlife-1 (flow by pass system) would reduce the potential impacts to regulated waters during maintenance of appurtenant structures to a less than significant level. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring are performed to meet the requirements of the DSOD and FERC as well as to ensure continued safe delivery of water and flood protection. Inspections and monitoring are minimally intrusive activities and thereby would not significantly impact wetlands and open waters. Closing of valves for inspections may require flow bypass systems. Impacts from flow bypass are discussed in the previous section under Maintenance of Dam Appurtenances and Equipment and potential impacts to water quality are discussed in Section 3.4 Hydrology and Water Quality. In the rare instance that regulated waters are to be directly impacted by exploratory work including, but not limited to, dredging and filling, trenching or boring within aquatic habitat, or removal of hydrophytic vegetation, compensation mitigation would be implemented to offset the impact (per MM Vegetation-5) and would reduce the potential impacts to regulated waters to a less than significant level. RESERVOIR DEWATERING Wetland habitats could be impacted by increased flows and scouring that could cause erosion as well as through reduced water availability and flows once the dewatering is complete. Potential impacts and mitigation related to riparian habitat are discussed under section June 2011 Page 3-45

98 Section 3.2 Vegetation and Habitat CHAPTER Potential to Conflict With Any Local Policies or Ordinances There are no local biology related policies or ordinances that pertain to this project. In particular, the project is exempt from the Santa Clara County s tree preservation and removal ordinance due to the fact that all project sites, with the exception of Rinconada Treated Reservoir Dam which is owned by the District, fall within District-owned land in various County parks. Furthermore, vegetation maintenance is exempt from tree removal permit requirements in the Santa Clara County tree removal ordinance (Santa Clara County 1998). In addition, there are no heritage trees that would be affected by the DMP activities. 9 Therefore, DMP activities would not result in any significant affects to local policies or ordinances Potential to Conflict With the Provisions of the Three Creeks Habitat Conservation Plan (HCP) or the Valley Habitat Conservation Plan (SCV HP) These two plans are described in further detail in Wildlife Section To the extent of geographical overlap, all of the DMP activities that have potential impacts on vegetation are covered in the SCV HP in terms of their impacts and mitigation measures. Although the SCV HP has not yet been finalized, the mitigation measures for the DMP have been closely coordinated with the mitigation measures in the SCV HP. Thus, DMP activities would not conflict with the provisions of the SCV HP. The Three Creeks HCP is currently in the preparation stage; however, great care has been taken to ensure that the covered activities of the DMP are described in a manner consistent with the HCP. To the extent that DMP impacts to vegetation are covered in the Three Creeks HCP, DMP activities would not conflict with the provisions of the Three Creeks HCP MITIGATION AND COMPENSATION MEASURES Impacts to special status plant species and sensitive natural communities will be determined prior to work being conducted and will be avoided or minimized to the extent feasible by employing applicable on a site specific basis. If avoidance and minimization measures cannot be employed to reduce or eliminate potential impacts, the District will mitigate the impact to a less than significant level utilizing the following measures. In all cases, appropriate levels of compensation will be determined prior to incurring the impacts, and mitigation will precede impacts. 9 Per Santa Clara County Code: Heritage tree shall include any tree which, because of its history, girth, height, species, or other unique quality, has been recommended for inclusion on the heritage resource inventory by the Historical Heritage Commission and found by the Board of Supervisors to have special significance to the community, and which has therefore been included in the heritage resource inventory adopted by resolution of the Board of Supervisors. June 2011 Page 3-46

99 Section 3.2 Vegetation and Habitat CHAPTER 3 The District s approach to mitigation for impacts to special status plant species and sensitive natural communities is comprised of three main components: 1. Perform additional botanical survey work over the course of the DMP to periodically update population size, location and other relevant biological information as well as to search for new occurrences of special status plant species (MM Vegetation-1). 2. Avoid and minimize impacts to special status species through restrictions in vegetation management methods, maintenance and construction activities (BMPs BI-10, BI-11, BI-12, and BI-13) 3. If avoidance and minimization measures cannot be employed to reduce or eliminate the impact, the District will compensate for impacts to special status plant populations and sensitive habitat for impacts prior to commencement of the DMP activities that could impact such resources (MM Vegetation-2, MM Vegetation-3, MM Vegetation-4, and MM Vegetation-5). An accounting system would be established and maintained prior to initiation of the DMP and throughout the life of the DMP to ensure that adequate mitigation occurs before incurring impacts to special status species or sensitive habitat ( pay-as-you-go ). The District will mitigate for unavoidable permanent impacts to special status species and habitat by protecting and/or providing for long-term management of suitable compensatory lands. The District will provide compensatory mitigation on a pay-as-you-go basis, by implementing one of the following options: a. The District shall participate in an appropriate regional HCP, such as the proposed Santa Clara Valley HP or Three Creeks HCP, when and if approved and implemented; or b. The District shall provide for compensatory mitigation by using existing USFWS and CDFG approved mitigation banks in appropriate ecological regions; or c. The District shall provide for compensatory mitigation by protecting appropriate mitigation lands and populations of special status species in perpetuity. For item (a) above, the covered activities will be clearly described in the approved Habitat Plan, and the District will make the appropriate contribution required to fully compensate for the impacts in accordance with the approved conditions and protocol. For items (b) and (c) in the above approach to providing compensatory mitigation, the District will be responsible for preservation or creation of populations of special status species to offset impacts to populations. For impacts to special status habitat, the District will be responsible for conservation of habitat that fully offsets the function and value of the habitat impacted; to this end, the District will provide suitable compensation for impacted special status species and habitat that meets the following criteria: a. Replacement habitat for special-status species populations or sensitive habitat will be determined in consultation with the appropriate regulatory agencies; b. Compensatory mitigation may occur on-site or off-site, as appropriate and in consultation with the appropriate regulatory agencies; June 2011 Page 3-47

100 Section 3.2 Vegetation and Habitat CHAPTER 3 c. The site will provide suitable replacement habitat at a ratio of not less than 3:1 for all sensitive natural communities; d. Decisions regarding the choice between population preservation or creation will be determined in consultation with the appropriate regulatory agencies; and e. Site(s) will not contain known hazardous materials or other conditions which would make them unsuitable for plant species conservation. The District will provide adequate funding for compensatory mitigation on an agreed-to schedule, following the discussion with the regulatory agencies, to ensure long-term protection and management of lands acquired or placed under conservation easement. The following principles will be applied to all compensation mitigation: 1. In order for a population to count as protected, there will be a buffer of at least 500 feet between the population and adverse land uses. Adverse land uses include permanent land uses that could endanger the long-term viability of the population; including urban development, landfill, and other intensive land uses. This buffer may be reduced in specific circumstances under direction of a qualified botanist. A 500-foot buffer was recommended in the Recovery Plan for Serpentine Soil Species of the San Francisco Bay Area (USFWS 1998c). 2. Because the compensation land may also contain occurrences of several covered species, acquisition could result in protection of multiple species. Protected populations should be of equal or greater size and quality as the populations that will be impacted under the DMP, per MM Vegetation-2. A suitable population size of a protected plant to ensure long-term viability and persistence will be determined on a species-specific basis, upon consultation with a qualified botanist and the appropriate regulatory agencies. 3. Land acquisition to compensate for loss of sensitive natural communities (MM Vegetation-2 and MM Vegetation-3) may also be used for preservation of special status plant species impacted by project activities, or to create new populations of special status plant species for compensatory mitigation. The suitability and mitigation credits for acquisition of habitat to serve multiple purposes and objectives will be determined upon consultation with a qualified botanist and the appropriate regulatory agencies. 4. Compensatory mitigation for sensitive natural community (habitat) impacts can be carried out through three methods, in order of preference: a. the preservation of an existing sensitive natural community; b. the restoration or enhancement of a previously-existing sensitive natural community; or c. the establishment (i.e., creation) of a sensitive natural community (dependent upon appropriate soils, geology, hydrology, etc.). June 2011 Page 3-48

101 Section 3.2 Vegetation and Habitat CHAPTER 3 5. The District shall use information from any existing studies, as available, to determine factors limiting the expansion of extant populations, as well as those necessary for establishment and maintenance of new populations and the adequate management of healthy functioning sensitive natural communities. Studies may include the effect of fire on seed germination and other possible germination requirements, the requirements for successful transplanting to augment new populations, and/or various factors related to management and micro-site needs of the species at all life stages from germination through maturity. Adaptive management decisions can then be developed on the basis of monitoring results to mitigate, minimize, or eliminate limiting factors. The following BMPs will be employed whenever applicable and feasible (See Appendix V for complete text of BMPs): BI-10: Minimize Impacts to Vegetation Whenever Clearing (or Trimming) is Necessary BI-11: Minimize Root Impacts to Woody Vegetation BI-12: Avoid Special Status Plant Species and Special Status Natural Communities BI-13: Plant Local Ecotypes of Native Plants and Choose Appropriate Erosion Control Seed Mixes The following Mitigation Measures will be applied: MM Wildlife-1: Alternative source of flow for streams to bypass flow around a dam for short term maintenance which would otherwise cause cessation of reservoir releases (complete description under Wildlife in Section 3.3). MM General-4: Limit crushing of woody debris to previously disturbed areas. MM Vegetation-1: Conduct Periodic Botanical Surveys. In order to ensure that the most current biological information is utilized in project impact analysis (includes new species agency listings, potential new occurrences in the project areas, and updates of existing field data), a survey of special status plant species will be conducted prior to implementing site specific DMP activities and thereafter a minimum of once every 5 years, or more frequently if conditions change as determined by qualified botanist or plant ecologist. Prior to conducting field surveys, a literature search shall be performed to identify special status species that may occur in the project areas or directly adjacent the project areas and a list of species for protocol level, focused botanical surveys will be generated (an update to Table 3.2-3). Special emphasis will be placed on focusing surveys in areas of suitable habitat. Sources to be consulted shall include but are not limited to CNDDB, CNPS, USFWS lists, Soil Conservation Service soils maps, USGS, DFG, species occurrence data from other relevant projects, suitable habitat areas, etc. Surveys will be conducted using the most recent taxonomic information and revisions available. June 2011 Page 3-49

102 Section 3.2 Vegetation and Habitat CHAPTER 3 Surveys shall be floristic in nature and will follow the CNPS Botanical Survey Guidelines (CNPS 2001). Surveys shall be conducted by a qualified botanist. Special status species identified during the surveys shall be mapped and documented. A report of occurrences will be submitted to CNDDB. If special status plant populations are identified, avoidance, minimization, and/or compensation measures will be required. MM Vegetation-2: Protection, Enhancement and Preservation for Sensitive Plant Species. For unavoidable impacts to sensitive plant species, the District shall protect, through land acquisition or a conservation easement, a population of equal or greater size and health. Compensatory mitigation for partial impacts to populations (except for Coyote ceanothus and San Francisco collinsia) is not required if, after 5 years of monitoring for annual plants and 3 years of monitoring for perennial plants, the population returns to a similar size and health. A loss of 15% or more of the original population size will result in mitigation. Any partial impact to a population of Coyote ceanothus will require compensatory mitigation, regardless of viability of the remaining population, and is limited to 3,650 individuals or 5% of the population adjacent to Anderson Dam, whichever is less. If it is not feasible to acquire and preserve a known population of a special status plant to be impacted, the District shall acquire and preserve suitable, unoccupied habitat capable of supporting the species and will use this habitat to create a new population. The preserved habitat shall be of equal or better habitat quality and provide similar edaphic and ecological conditions to the impacted areas in terms of soil texture, extent of disturbance, vegetation structure, and dominant species composition, as determined by a qualified botanist or plant ecologist. For population creation, the following considerations will also be met: Prior to unavoidable and permanent disturbance to a population of a special status plant species, and in the event that a population of equal or greater size and health cannot be acquired and preserved, propagules shall be collected from the population to be disturbed. This may include seed collection or cuttings, and these propagules will be used to establish a new population on suitable, unoccupied habitat as described above. Transplantation may be attempted but will not be used as the primary means of plant salvage and new population creation. Creation of new populations will require identifying suitable locations and researching and determining appropriate and viable propagation or planting techniques for the species. It will also require field and literature research to determine the appropriate seed sampling techniques and harvest numbers for acquisition of seed from existing populations. The District shall provide adequate funding for compensatory mitigation on an agreed-to schedule, following a discussion with the regulatory agencies, to ensure long-term protection and management of lands acquired or placed under conservation easement. June 2011 Page 3-50

103 Section 3.2 Vegetation and Habitat CHAPTER 3 MM Vegetation-3: Serpentine Sensitive Natural Community Compensation. For unavoidable impacts to serpentine natural communities, the District shall protect or restore, through land acquisition or a conservation easement, comparable serpentine habitat to mitigate for the permanent loss of sensitive habitat using a 3:1 mitigation ratio. The serpentine habitat restoration or preservation shall be located within the same watershed to the extent feasible. The preserved or restored habitat shall be of equal or better habitat quality and provide similar functional value as the impacted areas in terms of edaphic suitability, slope and exposure, habitat architecture and complexity, species composition, and vegetation cover as determined by a qualified plant ecologist. A mitigation and monitoring plan shall be prepared by a qualified restoration ecologist and implemented by the project and shall include, but is not limited to, an evaluation of: The potential success of restoration activities, based on site-specific conditions (e.g., serpentine soils and geology, current land cover type) Historic conditions that supported or likely supported the target land-cover type (Grossinger et al. 2007) The proximity of the site to the area in which serpentine habitat was (or are predicted to be) lost to covered activities The proximity of the site to other intact serpentine habitat that supports, or is likely to support sensitive plant species The extent and quality of existing habitats (e.g., percent native vegetation and presence of nonnative species) The ability of the restored serpentine habitat to contribute to habitat connectivity Detailed restoration plans, including plans and specifications, will be developed for individual sites based on specific edaphic conditions; extent and quality of existing habitats; vegetation composition; and the potential for adverse effects (e.g., disturbance). Restoration plans shall satisfy the following requirements: Define restoration goals and objectives, performance indicators, and success criteria Collect and analyze baseline data (e.g., soil type and suitability for planting, past land use history/alterations) Identify suitable/feasible restoration measures Develop conceptual restoration designs Develop detailed restoration designs (plans and specifications) that identify and describe construction methods, planting areas and methods, planting species (including collection and propagation methods), and maintenance requirements June 2011 Page 3-51

104 Section 3.2 Vegetation and Habitat CHAPTER 3 Prepare an adaptive management and monitoring plan that includes descriptions of responsible parties; monitoring methods and schedule; indicators, success criteria and adaptive management measures MM Vegetation-4: Riparian Sensitive Natural Community Compensation. For unavoidable impacts to riparian sensitive natural communities, the District shall protect or restore, through land acquisition or a conservation easement, comparable riparian habitat to mitigate for the permanent loss of sensitive habitat using a 3:1 mitigation ratio. The riparian sensitive natural community preservation or restoration shall be located within the same watershed as the impacted habitat and adjacent to the remnant channel impact areas, to the extent feasible. The preserved or restored natural community shall be of equal or better habitat quality and provide similar functional value as the impacted areas in terms of habitat architecture and complexity, species composition, and age class distribution as determined by a qualified plant ecologist. A mitigation and monitoring plan shall be prepared by a qualified restoration ecologist and implemented by the project and shall include, but is not limited to, an evaluation of: The potential success of restoration activities, based on site-specific conditions (e.g., hydrology, soils) Historic conditions that supported or likely supported the target land-cover type (Grossinger et al. 2007) The proximity of the site to the area in which streams or riparian woodland/scrub were (or are predicted to be) lost to covered activities The proximity of the site to other intact riparian corridors that support, or are likely to support covered species The extent and quality of existing habitats (e.g., percent native vegetation and presence/absence of nonnative wildlife) The ability of the restored stream and/or riparian woodland/scrub to contribute to habitat connectivity Detailed restoration plans, including plans and specifications, shall be developed for individual sites or stream reaches based on specific geomorphic, hydraulic, and hydrologic conditions; extent and quality of existing habitats; existing wildlife use; and the potential for adverse effects (e.g., disturbance and/or removal of existing habitat or wetlands). Restoration plans shall satisfy the following requirements: Define restoration goals and objectives, performance indicators, and success criteria Collect and analyze baseline data (e.g., soil type and suitability for riparian planting, low-flow conditions, past land use history/alterations) Identify suitable/feasible restoration measures Develop conceptual restoration designs June 2011 Page 3-52

105 Section 3.2 Vegetation and Habitat CHAPTER 3 Develop detailed restoration designs (plans and specifications) that identify and describe construction methods, planting areas and methods, planting species (including collection and propagation methods), and maintenance requirements Prepare an adaptive management and monitoring plan that includes descriptions of responsible parties; monitoring methods and schedule; indicators, success criteria and adaptive management measures Enhancement of riparian woodland and scrub shall include enhancing the cover, density, structural diversity, and species diversity of riparian vegetation in the understory or small stream segments, as well as removing invasive plants such as giant reed. MM Vegetation-5: Wetland Sensitive Natural Community Compensation. For unavoidable impacts to wetlands, the District shall protect or restore, through land acquisition or a conservation easement, comparable wetland habitat to mitigate for the permanent loss of sensitive habitat using a 3:1 mitigation ratio. The preserved or restored wetlands shall be of equal or better habitat quality and provide similar functional value as the impacted areas in terms of habitat architecture and complexity, hydrology, species composition, and vegetation cover as determined by a qualified plant ecologist. Potential wetland restoration and/or creation sites shall be selected within the same basin (i.e., San Francisco Bay or Monterey Bay) in which the expected wetland impacts will occur, where feasible. This prioritization will ensure that wetland mitigation occurs relatively close to the impact area and preserves and enhances watershed functions within each basin. Restoration will occur on suitable soils and in areas where wetlands may have historically occurred and have since been drained or severely degraded. Wetland enhancement measures shall be designed for specific wetland types (e.g., hydrogeomorphic context, surrounding natural community) and, in some cases, for specific sites. All restored wetlands restored shall be designed to support special status species such as the California red-legged frog; foothill yellow-legged frog, etc., (Section 3.3. Wildlife in this PEIR) where feasible. Sites designed to support breeding habitat for special status amphibians must have adequate nearby upland refugia habitat, Restoration sites for wetlands must be buffered by minimum distances ( feet, depending on surrounding land use) from urban development. Restoration of seasonal wetland will occur on sites with appropriate hydrology. Appropriate sites include areas where seasonal wetlands historically occurred and have since been drained or severely degraded. Additional appropriate sites include those that are appropriate for seasonal wetlands that did not historically support them because of changing land uses and altered hydrologic flows. A mitigation and monitoring plan shall be prepared by a qualified restoration ecologist and implemented by the project and shall include, but is not limited to, an evaluation of: The potential success of restoration activities, based on site-specific conditions (e.g., hydrology, soils) June 2011 Page 3-53

106 Section 3.2 Vegetation and Habitat CHAPTER 3 Historic conditions that supported or likely supported the target land-cover type (Grossinger et al. 2007) The proximity of the site to the area in which wetlands were (or are predicted to be) lost to covered activities The proximity of the site to other intact wetlands that support, or are likely to support covered species The extent and quality of existing habitats (e.g., percent native vegetation and presence/absence of nonnative wildlife) The ability of the restored wetlands to contribute to habitat connectivity Detailed restoration plans, including plans and specifications, shall be developed for individual wetlands based on specific geomorphic, hydraulic, and hydrologic conditions; extent and quality of existing habitats; existing wildlife use; and the potential for adverse effects (e.g., disturbance and/or removal of existing habitat or wetlands). Restoration plans shall satisfy the following requirements: Define restoration goals and objectives, performance indicators, and success criteria Collect and analyze baseline data (e.g., soil type and suitability for wetland planting, low-flow conditions, past land use history/alterations) Identify suitable/feasible restoration measures Develop conceptual restoration designs Develop detailed restoration designs (plans and specifications) that identify and describe construction methods, planting areas and methods, planting species (including collection and propagation methods), and maintenance requirements Prepare an adaptive management and monitoring plan that includes descriptions of responsible parties; monitoring methods and schedule; indicators, success criteria and adaptive management measures MITIGATION MEASURES FOR DEWATERING The District will implement the following measures to mitigate impacts resulting from dewatering. MM General-1: Before any reservoir dewatering takes place, the District shall conduct a project level CEQA review of the reservoir dewatering. MM General-2: Before any reservoir dewatering takes place, the District shall consult with CDFG and any other applicable resource agency and obtain all necessary permits. June 2011 Page 3-54

107 Section 3.2 Vegetation and Habitat CHAPTER 3 MM General-3: Before any reservoir dewatering takes place, the District shall develop a reservoir specific dewatering plan. Each dewatering plan shall include the following mitigation components: 1. To minimize the potential effect of impact 1 (flushing effects of flows needed to drain the reservoirs) the plan shall include provisions for ramping so that changes in flow are gradual. To the extent feasible, ramping shall be designed so that flows will not exceed winter base flows. 2. To minimize the effect of impact 2 (low flows following reservoir dewatering) the plan shall include provisions for supplemental water sources to maintain quantity and quality of downstream flow to the extent feasible. The supplemental water sources would be designed to supply water to the affected streams in the reaches below the District's dams during periods of dam dewatering for maintenance. To convey supplemental water sources, to the extent feasible, the plan shall utilize existing pipelines or upstream facilities to supply water downstream of the dam maintenance work (e.g., Anderson or Calero) or include building infrastructure to supply water at the base of the dam during dewatering events (e.g., Stevens Creek dam, where there are currently no existing facilities to supply water at the base of the dam). If supplemental flows cannot maintain the quantity and quality of water that would otherwise be available, additional provisions shall be included. (Impact 3, lower than average flows or a complete dry back could result in plant die off due to lack of hydrology, is addressed by MM Vegetation-6, below). MM Vegetation-6: Dewatering Vegetation Impacts Restoration. Following dewatering, stream channels will be monitored for riparian vegetation and/or special status plant species that have died in those locations downstream of dams where adequate supplemental water sources were not available. If any riparian or special status plant dieback is attributed to the dewatering, the riparian or special status plant shall be replaced utilizing passive recovery. In the event of failure of riparian sites to passively recover within two growing seasons, active restoration of the areas of dieback shall be implemented, in consultation with a qualified botanist. Watershed-specific propagules shall be used as source material. MM General-1 and -2 provide for project-level review and consultation, ramping, supplemental water and protective measures to address potential impacts to vegetation downstream of dams. MM General-1 and -2 ensure that prior to approval of any dewatering, a project-level environmental review will be conducted to analyze impacts and mitigation measures for individual reservoir dewatering projects. MM General-3 requires that before implementation of a dewatering event, the District prepare a dewatering plan that would include provisions for ramping and supplemental water. Ramping reduces changes to high level flows to the extent feasible thereby reducing impacts on downstream reaches. Supplemental water supplies during periods when reservoirs are dewatered would increase the level of protection for vegetation present in stream channels below the major dams. The objective of the supplemental flows is to the extent feasible to supply the quantity and quality of June 2011 Page 3-55

108 Section 3.2 Vegetation and Habitat CHAPTER 3 water that would otherwise be available. For any locations where adequate quantity and quality of water to fully support downstream aquatic organisms or vegetation is not available, the District would develop additional provisions. The table below provides a summary of potential supplemental water sources during dam dewatering events. A complete analysis of these mitigation measures and any residual impacts after implementation shall be provided in a project-level analysis. Reservoir Coyote Anderson Calero Almaden Guadalupe Lexington Stevens Chesbro Uvas Potential Supplemental Sources of Water *(facilities already in place) 1. Bypassed inflow 1. Bypassed inflow 2. Coyote Reservoir 3. Santa Clara Conduit* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Well-pipeline system 1. Bypassed inflow 1. Bypassed inflow These measures would be expected to reduce the potential effects of reservoir dewatering on downstream vegetation to a less than significant level. However, because additional project level review is required, impacts identified at that time could potentially be significant and unavoidable RESIDUAL IMPACTS AFTER MITIGATION Impacts would be less than significant after application of the listed mitigation measures, except potentially for those associated with reservoir dewatering. Because the effects of dewatering are addressed programmatically and further environmental review of dewatering is required, it is not known if the proposed mitigation measures will reduce all potential effects to a level of less than significant. Accordingly, dewatering has potentially significant and unavoidable impacts on special status plants and sensitive natural communities. June 2011 Page 3-56

109 Section 3.3 Wildlife CHAPTER WILDLIFE ENVIRONMENTAL SETTING Methods The seven USGS quadrangles in which the 14 dams or project areas occur were searched as well as the surrounding 20 USGS quadrangles via the California Natural Diversity Database (CDFG 2010) for documentation of special status wildlife species occurrences. Other sources of information included the Database for Special Status Amphibian and Reptile Species (SCVWD 1996), California s Wildlife, Volumes I, II, and III (Zeiner 1988), Endangered and Threatened Wildlife and Plants (USFWS 2006), and the Annual Report on the Status of California State Listed Threatened and Endangered Animals and Plants (CDFG 2010). Site visits were conducted between February 2006 and June 2007 to evaluate existing site conditions and potential impacts on biological resources from project DMP activities. Information on special status animal species was also compiled from the following sources: California Natural Diversity Data Base (CDFG 2010) Endangered and Threatened Wildlife and Plants (USFWS 2010) Annual Report on the Status of California State Listed Endangered, Threatened, and Rare Plants and Animals of California (CDFG 2005) Special Animals (CDFG 2010, California s Wildlife, Volumes I, II, and III (Zeiner et al., 1988a, b, c) Personal communications with District biologists regarding special status habitats and associated species Dams Rodent Burrow Removal (Phase II) Project Report. Prepared by H. T. Harvey & Associates. May (SCVWD 2010c) General Wildlife Santa Clara County is the home to a variety of wildlife species, with the 14 project areas providing suitable habitat within the nine vegetation communities identified (Figure Set III-1 in Appendix III). The dams support structural diversity, an abundance of food sources due to the complexity of vegetation, and are proximal to other habitat types resulting in high species richness and diversity of wildlife at the 14 project areas. A variety of amphibian species are likely present at all sites but Rinconada Treated Water Reservoir Dam. Thick leaf litter and decaying logs provide a moist microclimate suitable for species such as the ensatina (Ensatina eschscholtzii), arboreal salamander (Aneides lugubris), California slender salamander (Batrachoseps attenuatus), Pacific treefrog June 2011 Page 3-57

110 Section 3.3 Wildlife CHAPTER 3 (Pseudacris regilla), and western toad (Bufo boreas). The bullfrog (Lithobates catesbeiana), a non-native species, is abundant in many of the reservoirs and downstream creeks of the sites due to year round inundation. Reptile species either observed in the field or expected to occur in the site vicinities include, but are not limited to, western fence lizard (Sceloporus occidentalis), southern alligator lizard (Gerrhonotus multicarinatus), western rattlesnake (Crotalus viridis), California red-sided garter snake (Thamnophis sirtalis infernalis), and gopher snake (Pituophis catenifer). Numerous resident and migratory birds utilize the project sites, particularly due to the abundance of aquatic and woodland habitats. Resident species within the various project areas include the black phoebe (Sayornis nigricans), Stellar s jay (Cyanocitta stellari), western scrub jay (Aphelocoma californica), house finch (Carpodacus mexicanus), cliff swallow (Petrochelidon pyrrhonota), violet-green swallow (Tachycineta thalassina), northern rough-winged swallow (Stelgidopteryx serripennis), spotted towhee (Pipilo aculates), downy woodpecker (Picoides pubescens), Nuttall s woodpecker (Picoides nuttallii), acorn woodpecker (Melanerpes formicivorus), mourning dove (Zenaida macroura), California quail (Callipepla californica), American kestrel (Falco sparverius), red-tailed hawk (Buteo jamaicensis), and white-tailed kite (Elanus leucurus). Winter migrants include Townsend s and yellow-rumped warblers (Dendroica townsendi and D. coronata respectively), ruby-crowned kinglet (Regulus calendula), dark-eyed junco (Junco hyemalis), and white-crowned sparrow (Zonotrichia leucophrys). Summer migrants breeding in woodland habitats include orange-crowned warbler (Vermivora celata), Pacific-slope flycatcher (Empidonax difficilis), black-headed grosbeak (Pheucticus melanocephalus), and warbling vireo (Vireo gilvus). Both small and large mammals are expected to occur at the 14 project areas. Small mammals either observed onsite or known to occur in the vicinity include California ground squirrels (Otospermophilus beecheyi), Botta s pocket gophers (Thomomys bottae), California voles (Microtus californicus), western harvest mice (Reithrodontomys megalotis), California mice (Peromyscus californicus), ornate shrews (Sorex ornatus), dusky-footed woodrats (Neotoma fuscipes), and brush rabbits (Sylvilagus bachmani). These small mammals attract a variety of predators such as raccoons (Procyon lotor), skunks (Mephitis mephitis), coyotes (Canis latrans), gray fox (Urocyon cineroargenteus), bobcats (Lynx rufus), and cougars (Puma concolor). Black-tailed deer (Odocoileus hemionus columbianus) also frequent the project areas regularly. Wildlife species known to occur in the project vicinity are included in Appendix II to this EIR. Species observed at the 14 project sites during the site visits between February 2006 and June 2007 have been noted with an asterisk Special Status Wildlife Species Table lists the special status animal species, along with their status and habitat that have been documented in the project vicinity and could potentially occur within one or all of the project areas. All species queried were included in the table with the exception of species falling outside of the established range (coastal species, San Francisco Bay species, etc.). A few additional species have not been documented as occurring within the 27 U.S.G.S. quadrangles queried, but are either commonly accepted as occurring in the June 2011 Page 3-58

111 Section 3.3 Wildlife CHAPTER 3 project vicinity or the project areas are within the known range of the species and are included in the table. Table 3.3-1: Special Status Animal Species Documented Within the Project Vicinity Species Status Habitat Species Listed as Threatened or Endangered under the State and/or Federal Endangered Species Act Bay Checkerspot Butterfly (Euphydryas editha bayensis) Steelhead Trout (Oncorhynchus mykiss irideus) California Tiger Salamander (Ambystoma californiense) California Red-legged Frog (Rana draytonii) Bald Eagle (Haliaeetus leucocephalus) Least Bell s Vireo (Vireo bellii pusillus) Willow Flycatcher (Empidonax trailii) FE FT FT, CSC, CC for CESA candidate FT, CSC CE, CP FE, CE FE (extimus) FT (brewsteri) Native grasslands on serpentine soils. Host plant is Plantago erecta. Adults migrate up fresh water rivers or streams in the winter and spend the remainder of the time in the ocean. Juveniles remain in the fresh water rivers or streams typically for two years. Breeds in seasonal ponds or wetlands of central California; adults seek refuge in upland habitats adjacent to the breeding sites. Rivers, creeks and stock ponds of the Sierra foothills and coast range, preferring pools with overhanging vegetation adults seek refuge in upland habitats adjacent to the aquatic habitat. Winters near lakes, streams, or other bodies of water in much of California, with breeding occurring primarily in Alaska. Breeds in riparian woodlands, with understories dominated by shrubby willow thickets. Breeds in mesic areas of the Central Valley and Sierra Nevada. State Species of Special Concern, Protected Species, Candidate Species Chinook Salmon (Central CSC Valley Fall-Run) Adults migrate up fresh water rivers or streams in the spring and spend the remainder of the time in the ocean. (Oncorhynchus tshawytscha) Foothill Yellow-legged Frog (Rana boylii) California Horned Lizard (Phrynosoma coronatum frontale) Western Pond Turtle (Actinemys marmorata) CSC CSC CSC Found primarily in swiftly flowing creeks with cobble-sized substrate adults seek refuge in upland habitats adjacent to the aquatic habitat. Loose, friable soils of washes, grasslands, scrublands, oak woodlands, etc. of central California in areas supporting native ant populations. Open slow-moving water of rivers and creeks of central California with rocks and logs for basking. June 2011 Page 3-59

112 Section 3.3 Wildlife CHAPTER 3 Table 3.3-1: Special Status Animal Species Documented Within the Project Vicinity White-tailed Kite (Elanus leucurus) Northern Harrier (Circus cyaneus) Golden Eagle (Aquila chrysaetos) Burrowing Owl (Athene cunicularia) Long-eared Owl (Asio otus) Species Status Habitat Loggerhead Shrike (Lanius ludovicianus) California Yellow Warbler (Dendroica petechia brewsteri) Tricolored Blackbird (Agelaius tricolor) Black Swift (Cypseloides niger) Vaux s Swift (Chaetura vauxi) Townsend s Big-eared Bat (Plecotus townsendii townsendii) California Mastiff Bat (Eumops perotis californicus) Pallid Bat (Antrozous pallidus) San Francisco Dusky-footed Woodrat (Neotoma fuscipes annectens) CP CSC CSC, CP CSC CSC CSC CSC CSC CSC CSC CSC CSC CSC CSC Open grasslands and agricultural areas throughout central California. Frequents meadows, grasslands, open rangelands, freshwater emergent wetlands; uncommon in wooded habitats. Typically frequents rolling foothills, mountain areas, sagejuniper flats and desert. Found in open, dry grasslands, deserts and ruderal areas. Requires suitable burrows. This species is often associated with California ground squirrels. Frequents dense, riparian and live oak thickets near meadow edges and nearby woodland and forest habitats. Breed in valley foothill hardwood up to ponderosa pine habitats. Nests in tall shrubs and dense trees, forages in grasslands, marshes, and ruderal habitats. Migrants move through many habitats of Sierra and its foothills. This species breeds in riparian thickets of alder, willow and cottonwoods. Breeds near fresh water in dense emergent vegetation. Migrants and transients found throughout many habitats of California. Breeds on cliffs in restricted areas of the state. Migrants and transients found throughout many habitats of California. Breeds in tree hollow in woodlands near water in Northern California. Primarily a cave-dwelling bat that may also roost in buildings. Occurs in a variety of habitats of the state. Frequents open, semi-arid to arid habitats, including conifer, and deciduous woodlands, coastal scrub, grasslands, palm oasis, chaparral and urban. Roosts in cliff faces, high buildings, trees and tunnels. Roosts in rocky outcrops, cliffs, and crevices with access to open habitats for foraging. May also roost in caves, mines, hollow trees and buildings. Found in hardwood forests, oak riparian and shrub habitats. June 2011 Page 3-60

113 Section 3.3 Wildlife CHAPTER 3 Table 3.3-1: Special Status Animal Species Documented Within the Project Vicinity Species Status Habitat Ringtail (Bassariscus astutus) American Badger (Taxidea taxus) CP CSC Occurs in riparian and heavily wooded habitats near water. Found in drier open stages of most shrub, forest and herbaceous habitats with friable soils. STATUS CODES: FE Federally Endangered CE California Endangered FT Federally Threatened CT California Threatened FPE Federally Endangered (Proposed) CR California Rare FC Federal Candidate CP California Protected CSC California Species of Special Concern CC California Candidate (FSC were not included in table due to their lack of regulatory status) BAY CHECKERSPOT BUTTERFLY (EUPHYDRYAS EDITHA BAYENSIS) The five project areas that are underlain by serpentine soils and/or bedrock (Almaden, Anderson, Calero, Chesbro, and Guadalupe) were evaluated for their suitability as Bay checkerspot butterfly habitat. Bay checkerspot butterflies require low growing, open serpentine grassland habitats that support their host plant, dwarf plantain (Plantago erecta), at a density of at least 300 individuals per square meter on north facing slopes, typically within a total habitat size of at least four acres (172,200 square feet) (Ray White, pers. comm. 2006). Populations commonly occur at elevations between 500 and 1,300 feet. The primary constituent elements of critical habitat for the Bay checkerspot butterfly include habitat components that provide (USFWS 2008): 1. The presence of annual or perennial grasslands with little to no overstory that provide north-south and east-west slopes with a tilt of more than 7 degrees for larval host plant survival during periods of atypical weather (for example, drought). 2. The presence of the primary larval host plant, dwarf plantain (Plantago erecta), and at least one of the secondary host plants, purple owl s-clover (Castilleja densiflora) or exserted paintbrush (Castilleja exserta), are required for reproduction, feeding, and larval development. 3. The presence of adult nectar sources for feeding. Common nectar sources include desertparsley (Lomatium spp.), California goldfields (Lasthenia californica), tidy-tips (Layia platyglossa), sea muilla (Muilla maritima), scytheleaf onion (Allium alcifolium), false babystars (Linanthus androsaceus), and intermediate fiddleneck (Amsinckia intermedia). June 2011 Page 3-61

114 Section 3.3 Wildlife CHAPTER 3 4. Soils derived from serpentinite ultramafic rock (Montara, Climara, Henneke, Hentine, and Obispo soil series) or similar soils (Inks, Candlestick, Los Gatos, Fagan, and Barnabe soil series) that provide areas with fewer aggressive, nonnative plant species for larval host plant and adult nectar plant survival and reproduction. Serpentine habitat was completely absent from Guadalupe Dam. Almaden Dam did not support suitable serpentine grassland habitat or the required host plant, dwarf plantain. However, populations of the host plant were observed at Anderson, Calero Main, and Chesbro dams during field surveys conducted in 2006 and Four small isolated areas at Anderson Dam support populations of the host plant, dwarf plantain, but are considered unsuitable for the Bay checkerspot butterfly. There are two small populations north of the natural spillway below the concrete spillway, above the waterfall drop off. There is one small population above the boat ramp and one small population on the oak knoll southwest of the dam face. The dwarf plantain (Plantago erecta) populations at Anderson Dam were not suitable for the Bay checkerspot butterfly as they: Covered an area much smaller than the minimum that normally supports Bay checkerspot butterfly (each population comprised less than 3,200 square feet individually, with all four populations totaling less than 5,400 square feet in area. The desired total area to support Bay checkerspot butterfly is 172,200 square feet). Were not associated with secondary host plants such as purple owl s-clover (Castilleja densiflora) or exserted paintbrush (Castilleja exserta) Were not all located on north facing slopes, the populations above the spillway creek are south facing (Weiss et al. 1988) Occurred between 500 and 600 feet, which is the low end of the species typical elevation requirements Were associated with serpentinite chaparral habitat rather than serpentinite grassland habitat Were isolated from any other patches of Plantago erecta Were isolated from any documented occurrences of Bay checkerspot butterflies An isolated patch of the host plant was observed at Calero Main Dam, on a slope east of the dam face. The Plantago erecta population at Calero Main Dam was not suitable for the Bay checkerspot butterfly as it: Was comprised of two 150 square foot areas, which is considerably less than the desired 172,200 square foot area June 2011 Page 3-62

115 Section 3.3 Wildlife CHAPTER 3 Was not associated with secondary host plants including purple owl s-clover (Castilleja densiflora) or exserted paintbrush (Castilleja exserta) Was not located on north facing slopes, population is on a west facing slope (Weiss et al. 1988) Occurred at approximately 500 feet in elevation, which is the lowest end of the species typical elevation requirements Was located on a disturbed serpentine inclusion within chaparral habitat and not grassland habitat Was isolated from any other patches of Plantago erecta Was isolated from any documented occurrences of Bay checkerspot butterflies An isolated population of Plantago erecta was also observed at Chesbro Dam above the plunge pool in a chaparral opening. The Plantago erecta population at Chesbro Dam was not suitable for the Bay checkerspot butterfly as it: Was comprised of a 10,800 square foot area, which is considerably less than the desired 172,200 square foot area Was not associated with secondary host plants, including purple owl s-clover (Castilleja densiflora) or exserted paintbrush (Castilleja exserta) Occurred at approximately 500 feet, which is the lowest end of the species typical elevation requirements Was located within an opening of serpentinite chaparral habitat, not serpentinite grassland habitat Was isolated from any other patches of Plantago erecta Was isolated from any documented occurrences of Bay checkerspot butterflies Therefore, the Bay checkerspot butterfly has been determined to be absent from the project areas due to a lack of suitable habitat. SENSITIVE AVIAN SPECIES A number of avian species could rarely occur within the project areas during migration, dispersal, or occasional foraging due to their volant nature; avian species that could occur more regularly are discussed further below. The sensitive avian species that may occasionally occur at the project areas include the burrowing owl, long-eared owl, least Bell s vireo, California yellow warbler, willow flycatcher, black swift, and Vaux s swift. None of these species are expected to occur regularly on the sites due to the lack of suitable breeding habitat within the project boundaries and lack of nearby documented occurrences. Of these species, additional discussion is provided below for the burrowing owl which is considered the most likely of these species to be observed near the project areas. June 2011 Page 3-63

116 Section 3.3 Wildlife CHAPTER 3 There have been 56 documented occurrences of burrowing owls in Santa Clara County (CDFG 2010). Of these, 51 occurred below 400 feet elevation in the valley floor where owls are known to breed. A total of five occurrences of wintering or non-breeding owls have been reported above 400 feet in Santa Clara County. These include two occurrences in the Mt. Madonna USGS quadrangle at approximately 440 feet and 600 feet, one occurrence in the San Jose East USGS quadrangle at approximately 600 feet, one occurrence in the Lick Observatory USGS quadrangle at approximately 610 feet, and one occurrence in the Mt. Day USGS quadrangle at approximately 2,900 feet. These five owls were not breeding. Coyote and Stevens Creek dams are in areas where owls are not believed to occur due to their location on the outskirts of documented occurrences of the species as well as lack of suitable habitat. Almaden, Guadalupe, and Lenihan dams are generally located at 600 feet in elevation, which is above the typical elevation range for the species. The remaining nine dams (Anderson, the three dams at Calero, Chesbro, Coyote Percolation Ponds, Rinconada Treated Water Reservoir, Uvas, and Vasona), while providing marginal habitat at best for owls, were surveyed in accordance with the recommended protocols as outlined by the CDFG s Staff Report on Burrowing Owl Mitigation (1995) and the Burrowing Owl Survey Protocol and Mitigation Guidelines (California Burrowing Owl Consortium 1993) between March and June of The surveys included four rounds of appropriately timed surveys. No direct observations of individuals or indirect observations (i.e., white wash, feathers, pellets) of burrowing owls were documented during the numerous surveys that were conducted in the project areas throughout 2006 and Small mammal burrows were removed in 2009 and 2010 at all dams and no signs of burrowing owl presence were found (SCVWD 2010c). Therefore, it has been concluded that burrowing owls are not likely present. BATS A number of common and rare bat species, including those listed in Table 3.3-1, may frequent the reservoirs during nightly foraging. However, it is not believed that the project areas themselves provide suitable habitat for any locally occurring bat species due to the lack of roosting and breeding habitat. Bats are likely to pass over the project areas while foraging. AMERICAN BADGER (TAXIDEA TAXUS) American badgers are grassland specialists that are not commonly observed in Santa Clara County. There have been only four documented occurrences of American badgers in the County, none of which occurred near the dams (CDFG 2010). This species commonly occurs in areas supporting large swaths of grassland habitat with friable soils. The project areas support a mosaic of habitats, the majority of which are not underlain by a crumbly subsurface, with no area supporting vast expanses of grassland habitat typically utilized by the species. American badgers are not regular residents of fragmented grassland habitat, especially in areas influenced by human disturbances and are unlikely to occur in the project area. June 2011 Page 3-64

117 Section 3.3 Wildlife CHAPTER 3 CALIFORNIA HORNED LIZARD (PHRYNOSOMA CORONATUM FRONTALE) The California horned lizard has been recorded in numerous locations within Santa Clara County. The California horned lizard typically prefers loose, friable soils (such as sandy washes), but has been found to occupy areas with silty soils as well. The species also requires the presence of native ant populations and could be present in project areas. The horned lizard has been documented at Calero Auxiliary Dam (CDFG 2010) and could be present at other suitable sites within the project area. CALIFORNIA TIGER SALAMANDER (AMBYSTOMA CALIFORNIENSE) The California tiger salamander (CTS) is a large terrestrial salamander with adults attaining a total length of over 8 inches (203 millimeters) (Stebbins 1951). Dorsally, the background color appears to be jet black, normally with an overlain pattern of white or yellow spots, or bars (Stebbins 1985; Petranka 1998). Breeding of adult California tiger salamanders extends from late November through February, following the onset of winter rains (Storer 1925, Barry and Shaffer 1994). Both males and females engage in nocturnal breeding migrations traveling up to 1 mile (1.6 km) (Austin and Shaffer 1992) or more from subterranean refuge sites (e.g., small mammal burrows) within upland habitat (Loredo et al. 1961) to egg deposition sites (long-lasting rain-filled vernal pools) (Twitty 1941; Andersen 1968). A recent study has indicated that approximately 95 percent of salamander populations reside in upland habitat, underground within 2,000 feet of their breeding location, with 99 percent of the populations occurring within 0.7 miles (3,695 feet) (Trenham and Shaffer 2005). Embryos of California tiger salamanders hatch in approximately days after being laid (Storer 1925; Twitty 1941) and the resulting gilled, aquatic larvae ( inches ( mm) in length) require a minimum of about weeks to complete development through metamorphosis. Following metamorphosis (normally from early May through July), juveniles emigrate en masse at night from the drying breeding pond after spending a few hours or days near the pond margin (Holland et al. 1990). Juvenile salamanders wander into small mammal burrows or deep cracks in the soil, which they use as refugia during the hot summer and fall months (Shaffer et al. 1993, Loredo et al. 1996). Data suggest that most individuals require 2 years to become sexually mature, but some individuals may be slower to mature during periods of drought or a seasonal rainfall (Shaffer et al. 1993). Anecdotal evidence indicates that salamanders have a high degree of site fidelity to their breeding ponds and also to the small mammal burrows they use for refugia (Shaffer et al. 1993). Sites used for reproduction are typically natural pools that fill with rainwater and artificial stock ponds; however, salamanders have also been observed to breed in springs, wells, artificial reservoirs, quarry ponds, man-made canals, and rarely, in the slack waters of oxbows in small- to medium-sized streams. Such sites may, or may not contain dense amounts of aquatic and streamside vegetation. The highest numbers of larvae appear to occur in aquatic habitats that are largely devoid of any vegetation and contain very turbid water. Salamanders may also turn up in certain man-made structures [e.g. wet basements, wells, swimming pools, underground pipes, and septic tank drains (Storer 1925, Pickwell June 2011 Page 3-65

118 Section 3.3 Wildlife CHAPTER ), sometimes many years after their local breeding site has been destroyed by urbanization. Juvenile and adult salamanders typically use the burrows of California ground squirrels (Otospermophilus beecheyi) and pocket gophers (Thomomys bottae) as underground refugia (Storer 1925, Jennings and Hayes 1994, Jennings 1996, Loredo et al. 1996), but may use a variety of burrows including cracks within the soil which may extend up to 15 feet (4.6 m) deep from the soil surface (Jennings, unpublished data). California tiger salamanders also use logs, piles of lumber, and shrink-swell cracks in the ground for cover (Holland et al. 1990). California tiger salamanders may occupy burrows up to 1.3 mile from their breeding sites during the non-breeding period (U.S. Fish and Wildlife Service 2005a). The project areas were evaluated for the suitability of California tiger salamander to breed and/or seek refuge in upland habitat within the project boundaries. The California tiger salamander is not likely to be present on all the dam faces due to the lack of suitable breeding habitat (ponds) within the species established dispersal range of the project sites, with the exception of Anderson, Coyote, Guadalupe, and Calero (Auxiliary, Fellows Dike, and Main) dams 10. Two of the Calero Reservoir dams (Fellows Dike and the Main Dam) are within critical habitat designated by the USFWS for the species (70 FR ). Anderson Dam is the only project area where a California tiger salamander has been documented within the project boundaries (CDFG 2010). On December 2, 2001, a single adult California tiger salamander was observed on the roadway between the parking lot and the dam. On January 25, 2011, a single adult California tiger salamander was found during a routine pre-work biological inspection in a weep hole in the floor of the Anderson Dam spillway. On April 18, 2002, there was another sighting of this species approximately 1,000 feet east of the Anderson Dam project area. Dr. Benjamin Fitzpatrick with the University of California at Davis observed more than 100 juveniles in a large seasonal pond surrounded by grassland and woodland habitat within the Rosenden area of Anderson Lake County Park located 1,000 feet from the Anderson Dam project area (CDFG 2010). In recent years, it has been discovered that the native California tiger salamander is hybridizing with the eastern tiger salamander (Ambystoma tigrinum), which was introduced for fish bait in the State of California. Dr. Benjamin Fitzpatrick, of the University of California at Davis, Department of Evolution and Ecology, collected DNA samples to run genetic testing for hybridization on the Rosenden pond salamanders on April 18, The results of the sampling were not published; however, on August 25, 2006, Live Oak Associates, Inc. contacted the Shaffer Lab at the University of California at Davis to inquire about the results. According to their laboratory logs, Dr. Fitzpatrick tested three genes from ten individuals for a total of 30 samples. Of the 30 samples, only one showed any signs of hybridization (Dylan Dittrich-Reed, pers. comm. 2006). Dr. Fitzpatrick, who is now at the University of Tennessee, confirmed these results on August 29, 2006 (Fitzpatrick pers. comm. 10 There is a documented occurrence of a CTS at Chesbro Reservoir in 1986 (CDFG 2010). As this citation was not mapped in CNDDB with high precision, the exact location is not known. If CTS was observed, the population is not believed to be located on the Chesbro dam face project area due to the lack of suitable breeding habitat. June 2011 Page 3-66

119 Section 3.3 Wildlife CHAPTER ). These limited results cannot rule out that the Rosenden pond salamanders are the native California tiger salamanders. The salamander observed at the base of Anderson Dam most likely dispersed from this offsite pond. Conditions of the Rosenden pond may not always be favorable for the California tiger salamander. On September 2, 2006, the depth of water was at least three to four feet, and a large, healthy population of juvenile and adult bullfrogs, a common predator of the California tiger salamander, was present within the pond. The extended length of inundation and the presence of bullfrogs was likely the result of two consecutive years of above average rainfall. During average or below average rainfall years, it is assumed that the Rosenden pond will dry and support very few, if any, predators, thereby becoming a suitable pond for California tiger salamander breeding once again. Drought conditions prevailed from but additional surveys have not been conducted. It has been presumed for the purpose of this report that California tiger salamanders continue to breed in the Rosenden pond and will do so for the life of the project. Energetic and survivorship considerations argue that there will be an inverse relationship with the number of individual California tiger salamanders in upland dry-season habitat and the distance from their breeding pond. The boundaries of the Anderson Dam project area begin as close as 1,000 feet from the Rosenden pond; however, the dam face itself is located greater than 2,000 feet from the pond, where scientific research suggests less than five percent of the population would seek upland refugia. Therefore, relatively few individuals are expected to occur within the project footprint at Anderson Dam. While this number is not expected to be zero, it is likely very small. However, if conditions have changed, and the Rosenden pond remains inundated year-round, this is likely an unstable condition for California tiger salamanders and they may become extirpated from the pond. California tiger salamanders are known to breed in the vicinity of Coyote Reservoir. However, the nearest documented breeding pool is more than 2 miles from Coyote Dam (CDFG 2010), further than the typical dispersal range of the species. California tiger salamanders may occur on Coyote Dam as occasional transients. There is a California tiger salamander breeding site documented on McAbee Creek, approximately 5,000 feet northwest of the project area at Guadalupe Dam (CDFG 2010). Although the location is at the far end of the typical dispersal range of the species, there are no barriers to movement from the breeding pond to the project area through the natural habitats of Almaden Quicksilver Park. Therefore, there is a low potential for California tiger salamanders to occur on Guadalupe Dam as occasional transients. California tiger salamanders are known to occur in the vicinity of Calero Reservoir. There has been only one California tiger salamander sighting documented within 3,960 feet (the upland range for this species) (USFWS 2004) of Calero Main Dam (CDFG 2010). This sighting was documented from a pool approximately 2,800 feet southwest of the Calero Main Dam, which is a distance where less than five percent of the population would seek upland refugia. Portions of the Calero Main Dam project area are within the upland range of the pool at the base of the Calero June 2011 Page 3-67

120 Section 3.3 Wildlife CHAPTER 3 Auxiliary Dam; thus, there is a small possibility that some foraging individuals could be present on the eastern portion of the Calero Main Dam site. A seasonal pool suitable for California tiger salamander breeding is present at the base of the Calero Auxiliary Dam face within the project boundaries. On March 27, 2007, Dr. Jennings and Ms. Molly Goble (permit number TE ), with authorization given by Vincent Griego with the USFWS on March 22, 2007, conducted larval surveys of this pool. Surveys were not conducted in April and May of 2007 due to drying of the pool. The only species observed within the pool in March 2007, as well as during previous site surveys, were Louisiana red-swamp crayfish (Procambarus clarkii) and Pacific treefrog larvae; no California tiger salamander larvae or adults were observed. Nonetheless, this pool is considered marginally suitable breeding habitat for the salamanders. A total of four sightings have been documented within 3,960 feet of the Calero (Fellows Dike) Dam, with two of these occurring within 2,000 feet (CDFG 2010). All of these sightings are, however, on the opposite side of McKean Road, which serves somewhat as a barrier to salamander movement. A final rule on the designation of critical habitat for the California tiger salamander was issued by the USFWS on August 9, 2005 (70 FR ). Critical habitat is present at Calero (Fellows Dike) and Calero Main dams (see Figure Set III-3 in Appendix III). Both of these dams are within the same unit, East Bay Region Unit 8. Suitable breeding habitat is absent from both of these project areas, with the potential for foraging. CALIFORNIA RED-LEGGED FROG (RANA DRAYTONII) The California red-legged frog is a federally threatened species and is the largest native frog in California. Adults attain a length of inches ( mm) snout-to-vent length (SVL) (Jennings and Hayes 1994). On the dorsal surface, the background color varies from brown to gray to reddish-brown, normally with some dark mottling peppered around spots with light-colored centers (Stebbins 1985). The distribution of reddish pigment is highly variable, but is usually restricted to the groin and undersurfaces of the thighs, legs, and feet (Jennings and Hayes 1994). This red coloration is not diagnostic for species identification. Two distinctive, prominent folds of skin ( dorsolateral folds ), run in a complete line from the rear of the eyes to the groin. The groin has a distinctly mottled pattern of black on a light-colored background. Juvenile frogs range from inches (40-84 mm) SVL and have the same coloration as adults except that the dorsolateral folds are normally yellow or orange colored (Stebbins 1985). This coloration is distinct even at a distance. Larval frogs range from inches (14-80 mm) SVL. Adult California red-legged frogs have been observed breeding from late November through early May after the onset of warm rains (Storer 1925, Jennings and Hayes 1994). Male frogs typically attract females by emitting low short calls in small mobile groups of 3-7 individuals (Jennings and Hayes 1994). Females move toward the calling groups and amplex a male. Following amplexus, the females move to chosen oviposition sites where they attach an egg mass of 2,000-6,000 moderate-sized ( mm diameter) eggs to an emergent vegetation brace such as tule stalks, June 2011 Page 3-68

121 Section 3.3 Wildlife CHAPTER 3 grasses, or willow roots located just below the water surface (Storer 1925, Livezey and Wright 1947). Once laid, the egg mass will swell with water for about 24 hours, finally reaching the size of a softball. Males usually remain at the breeding sites for several weeks after reproduction before moving to foraging habitats, while females immediately remove to foraging habitats. California red-legged frog embryos hatch about 6-14 days following fertilization. The resulting larvae ( mm) require weeks to reach metamorphosis, which usually occurs between July and September, although there are scattered observations of overwintering larvae in perennial ponds such as at the arboretum at Golden Gate Park in San Francisco (Jennings, personal observation). Tadpoles generally metamorphose at mm total length (Storer 1925) and the newly emerged juvenile frogs are generally mm SVL. Larvae are thought to graze on algae, but they are rarely observed in the field because they spend most of their time concealed in submergent vegetation, algal mats or detritus (Jennings and Hayes 1994). Post-metamorphic frogs grow rapidly feeding on a wide variety of invertebrates. Males typically reach sexual maturity at 2 years and females at 3 years; however, frogs of both sexes may reach sexual maturity in a single year if resources are sufficient (Jennings, unpublished data). Conversely, frogs may take 3-4 years to reach maturity during extended periods of drought (Jennings and Hayes 1994). Based on limited field data, California red-legged frogs appear to live up to 10 years in the wild (Jennings, unpublished data). Adult frogs eat a wide variety of animal prey including invertebrates, small fishes, frogs, and small mammals. California red-legged frogs have been observed in a number of aquatic habitats throughout their historic range. Larvae, juveniles, and adult frogs have been collected from natural lagoons and lakes, dune ponds, natural pools in or next to streams, streams, marshlands, sag ponds, and springs, as well as human-created stockponds, secondary and tertiary sewage treatment ponds, wells, canals, golf course ponds, irrigation ponds, and sand and gravel pits (containing water) (Jennings 1988). Breeding and foraging occurs in these habitats when perennial (or near perennial) water is present with a general lack of introduced aquatic predators such as largemouth bass (Micropterus salmoides), green sunfish (Lepomis cyanellus), and bluegill (L. macrochirus), crayfish (Pacifastacus leniusculus and Procambarus clarkii), and bullfrogs (Lithobates catesbeiana). The aquatic habitats and surrounding upland habitats within the project areas were evaluated for the potential occurrence of this species. Aquatic habitats downstream of some dams may have potential breeding and foraging habitat; the large reservoirs behind the dams are not considered suitable aquatic habitat due to the presence of aquatic predators. Grasslands, chaparral and coastal scrub habitats, oak woodlands, riparian forest/scrub, and conifer woodlands within 100 feet of suitable aquatic habitat are characterized as upland refugia; while grasslands, chaparral and coastal scrub habitats, oak woodlands, riparian forest/scrub, and conifer woodlands beyond 100 feet but within 2 miles of suitable aquatic habitat are characterized as dispersal habitat. Dispersing frogs have been recorded to cover distances from 0.25 mile to more than 2 miles without apparent regard to topography, vegetation type, or riparian corridors (Bulger 1998). Dispersing frogs may take utilize small June 2011 Page 3-69

122 Section 3.3 Wildlife CHAPTER 3 mammal burrows, incised stream channels, shelter under boulders, rocks, logs, leaf litter, agricultural drains, watering troughs, abandoned sheds, or unused farm equipment as cover (Jennings and Hayes 1994). Dispersal and migration movements are generally straight-line, point-to-point migrations rather than along specific habitat corridors (U.S. Fish and Wildlife Service 2006; Stebbins 2002). Dispersing frogs may use long-established historic migratory pathways that provide specific sensory cues as guidance (Stebbins 2002). Potential suitable aquatic habitat for California red-legged frogs is present in the aquatic and riparian habitats, in the vicinity of Almaden, Calero Main, Chesbro, Coyote, Guadalupe, Lenihan, Stevens Creek, and Uvas dams. As a result, upland refugia and dispersal habitats for the species may be present at these dams in the vegetated habitats associated with upland refugia and dispersal. However, earthen dams in general may not provide suitable refugia due to their dry nature, direct exposure to sunlight, low vegetative cover, and substrate composition (i.e., rock, gravel, or compacted substrates). It has been reported that most ground squirrel burrows on SCVWD dams are not deep; the majority were less than two feet deep, possibly due to the hard, compacted fill of the dams (SCVWD 2010c). Burrows of this depth are unlikely to maintain the range of temperature and humidity requirements to support California red-legged frog aestivation. Suitable habitats have been determined to be absent from Anderson, Calero Auxiliary and Fellows Dike, Rinconada Treated Water Reservoir, and Vasona dams due to the lack of potential breeding sites free of aquatic predators, isolation by urbanized development, and other human disturbance factors. There is a slight potential that California red-legged frogs will be reintroduced to the Coyote Percolation Ponds Dam vicinity. A mitigation wetland for the Stream Maintenance Program has been created adjacent to the north side of the project area. If a California red-legged frog population is successfully established in this wetland, there is a potential that individual frogs could occur within the project boundaries as well. However, at this point, plans have not been finalized as to the likelihood of this pond being managed for California red-legged frogs. The only project location where any life stages of the California red-legged frog have been observed during these surveys was at Coyote Dam. It has been reported that TRA Environmental Sciences, Inc. observed a single adult on Coyote Dam on February 15, 2007 (TRA Environmental Sciences, Inc., pers. comm. 2007). In summary, for the purposes of this project, it is assumed that California red-legged frogs could be present at Almaden, Calero Main, Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, and Uvas dams. BALD EAGLE (HALIAEETUS LEUCOCEPHALUS) The bald eagle is a large brown eagle with a white head and tail in the family Accipitridae. This species is 31 to 37 inches in length and has a 70- to 90-inch wing span. Juveniles are mostly dark, acquiring the white head and yellow beak within five years of age. Bald eagles are found near water ecosystems from central Alaska down to northern Mexico, in areas that provide adequate food sources, perching sites, and nesting sites near large water sources with an abundance of tall, large trees. This species feeds mainly on fish, with some meals consisting of waterbirds or June 2011 Page 3-70

123 Section 3.3 Wildlife CHAPTER 3 turtles. Typically this bird is solitary, rarely being found in groups. Most pairs nest in Canada and Alaska, but there are a few resident bald eagle pairs in the state of California that remain here year round. Nests are made of sticks with an under layer of softer materials. Nests can reach up to six feet wide, weighing hundreds of pounds, and are used by the same pair of bald eagles for several years. Females typically lay two eggs. Fledglings can fly beginning at approximately 11 weeks and are fed for an additional four to five weeks. Many bald eagles over-winter in California. Migrants normally arrive in the state around November and migrate north in the spring in late March. This species has had a long history of decline. Up until the 1940 s, bald eagles were directly killed by hunters and indirectly affected by the decline of available habitat. Then in 1940, the Bald Eagle Protection Act was passes prohibiting the take, possession, sale, purchase, barter, offer to sell, purchase or barter, transport, export or import, of any bald eagle (16 U.S.C. 668). This Act helped the rapidly declining populations of bald eagles, but was not enough for recovery. Then after World War II, the use of dichloro-diphenyl-trichloroethane (DDT) became detrimental to their reproductive success. After the apparent effect of DDT on the bald eagle, USFWS listed the species as Endangered and DDT was later banned from use in the United States in Protection of this species was only strengthened in 1973 when the Endangered Species Act was passed. Since the 1970 s bald eagle populations have been making a comeback. On July 9, 2007, the bald eagle was officially delisted as Endangered by the USFWS (72 FR ). The bald eagle remains a state endangered and fully protected species. Bald eagles are known to winter at Calero Reservoir from November to March and are known to breed at Calaveras Reservoir (not a SCVWD reservoir) individual bald eagles been seen at Chesbro Reservoir, and Coyote Ridge (SCVAS 2010a). A bald eagle nest was reported at Coyote Reservoir in 2010 (SCVAS 2010a). None of the sightings or nests have been reported within the project areas and the project areas provide only marginal habitat where larger trees exist. CALIFORNIA WILDLIFE SPECIES OF SPECIAL CONCERN CHINOOK SALMON (ONCORHYNCHUS TSHAWYTSCHA) The project areas were evaluated to determine the suitability for Chinook salmon. Fall-run Chinook salmon have been documented as occurring in the Guadalupe and Coyote systems. This species could be present downstream from Almaden, Anderson, Calero Main, and Guadalupe dams, as well as on both sides of the Coyote Percolation Ponds Dam due to the fishway at that facility. The seasonal dry-back condition in Stevens Creek tends to preclude colonization of this system by fall-run Chinook salmon. The Camden Drop Structure, approximately two miles downstream of Vasona Dam, precludes further upstream access along Los Gatos Creek (including Lenihan Dam). Individuals would not reach Calero Auxiliary Dam and Fellows Dike due to the lack of connectivity with downstream habitat. Anderson Dam is an impassible barrier for fish attempting to reach Coyote Dam. Chinook salmon are not known as regularly occurring in the Pajaro River basin streams, which June 2011 Page 3-71

124 Section 3.3 Wildlife CHAPTER 3 encompass Chesbro and Uvas dams. Finally, Rinconada Treated Water Reservoir Dam is not located along a stream. FOOTHILL YELLOW-LEGGED FROG (RANA BOYLII) Foothill yellow-legged frogs are a highly aquatic amphibian, spending most or all of their life in or near streams, though frogs have been documented underground and beneath surface objects more than 50 meters (165 feet) from water (Nussbaum et al. 1983). Bourque (2008) reported the movements of radio-tracked frogs being restricted to the watercourse. This species is potentially present within the project area at Anderson, Almaden, Chesbro, Coyote, Coyote Percolation, Guadalupe, and Uvas dams. WESTERN POND TURTLE (ACTINEMYS MARMORATA) The aquatic habitat within the project areas was evaluated for the suitability for western pond turtles. It was concluded that potential habitat for this species is present within the project boundaries of all project areas but Rinconada Treated Water Reservoir Dam. An anecdotal report of a sighting of an individual Western pond turtle had been made in 1999 at the sludge drying ponds at the Rinconada Water Treatment Plant (SCVWD 2005d), but this species would not occur on the dam or any other area within the project boundaries as there is no open water or aquatic habitat associated with this dam. This species has also been documented at Almaden, Anderson, Chesbro, Coyote Percolation Ponds, Uvas, and Vasona (CDFG 2010). Additionally, Dr. Jennings observed western pond turtles at Almaden, Anderson, Chesbro, Coyote, Coyote Percolation Ponds, and Vasona dams during May and June WHITE-TAILED KITE (ELANUS LEUCURUS) The white-tailed kite is a fully protected species. The CDFG cannot issue a take permit for impacts to individual kites due to the fact that they are fully protected. CDFG can, however, authorize impacts to habitat suitable for the kite. Suitable breeding habitat is present for this species at all of the project sites, but Calero Auxiliary and Rinconada Treated Water Reservoir dams. These two unsuitable sites support very few trees, five small trees at Calero Auxiliary Dam and a few landscaped trees at Rinconada Treated Water Reservoir Dam, but it would be highly unlikely that a kite would build a nest in these two locations. The remaining 12 sites support a number of large mature trees suitable for breeding. NORTHERN HARRIER (CIRCUS CYANEUS) Suitable habitat for the northern harrier is restricted to the wetland area at the base of Calero Main Dam. This is the only site that supports large, dense stands of wetland vegetation for this ground nesting raptor. June 2011 Page 3-72

125 Section 3.3 Wildlife CHAPTER 3 GOLDEN EAGLE (AQUILA CHRYSAETOS) The golden eagle is not only a species of special concern, but is also listed as a fully protected species. As with the kite, the CDFG cannot issue a take permit for impacts to individual eagles due to the fact that they are fully protected. CDFG can however authorize impacts to habitat suitable for the eagle. Suitable breeding habitat is present for this species at all of the project sites, except Calero Auxiliary, Coyote Percolation Ponds, Rinconada Treated Water Reservoir, and Vasona dams. Calero Auxiliary and Rinconada Treated Water Reservoir dams support very few trees; five small trees and a few landscaped trees (respectively). It would be highly unlikely that an eagle would build a nest in these two locations. Coyote Percolation Ponds and Vasona dams are located in urbanized areas of the County. Golden eagles typically breed in more rural, open habitats. The remaining ten sites support a number of large mature trees that may be suitable for breeding. LOGGERHEAD SHRIKE (LANIUS LUDOVICIANUS) Suitable breeding habitat is present for the loggerhead shrike at all of the project sites, except Calero Auxiliary and Rinconada Treated Water Reservoir dams. These two unsuitable sites do not support dense stands of tall shrubs or trees. The remaining 12 sites support either chaparral or woodland habitat suitable for breeding; all dams have open grasslands suitable for foraging. TRICOLORED BLACKBIRD (AGELAIUS TRICOLOR) Suitable habitat for the tricolored blackbird is restricted to the wetland area at the base of Calero Main Dam. This is the only site that supports large, dense stands of emergent wetland vegetation suitable for breeding by this species. Approximately 600 adults were observed in this wetland in April of 1989 (CDFG 2010). SAN FRANCISCO DUSKY-FOOTED WOODRAT (NEOTOMA FUSCIPES ANNECTENS) San Francisco dusky-footed woodrat nests are present at all of the project areas with the exception of the sites influenced by urbanization or those supporting little shrub or tree cover; the sites which woodrats are unlikely to inhabit are Calero Auxiliary, Calero (Fellows Dike), Rinconada Treated Water Reservoir, and Vasona dams. Known woodrat nest locations at Anderson, Almaden, Calero Main, Chesbro, Coyote, Coyote Percolation, Guadalupe, Lenihan, Stevens Creek and Uvas dams are shown in Appendix III, Figure Set-4. Surveys for woodrat nests were conducted by SCVWD biologists in 2006 and 2009 concentrating on chaparral and woodland habitats within 100 feet of dam faces. Aerial photos were utilized during the surveys to mark locations of woodrat nests and then GPS points were collected for mapping purposes using laser technology to obtain accurate points located under dense tree canopy that obscures satellite signals. June 2011 Page 3-73

126 Section 3.3 Wildlife CHAPTER 3 All dams with woodrat nests present had nests on the dam face or within 50 feet of the dam face. It should be noted that surveys did not include complete searches of all project site ARME and APE areas. Therefore, there is a potential that additional nests could be present where nests were observed and that nests could be present at the sites were nests were not previously identified. It is also possible that over the course of the program, the areas already surveyed could be (re-)occupied by this species. RINGTAIL (BASSARISCUS ASTUTUS) Ringtails are reclusive, nocturnal mammals that reside in the high canopies of the riparian trees and oak woodlands. Ringtails are primarily carnivorous but also do eat other food such as plants, fruit, and insects. Their diets generally consist of small mammals (rodents, rabbits, squirrels), small birds, insects (spiders, grasshoppers, crickets, centipedes, scorpions), and fruits (persimmon, mistletoe, hackberries). As well, the diet varies throughout the year. In the fall, it consists of mostly plants and insects; in winter, mammals and birds; and in summer, insects (Williams 2001). The ringtail is a fully protected species. The CDFG cannot issue a take permit for impacts to individual ringtails due to the fact that they are fully protected. CDFG can however authorize impacts to habitat suitable for this species. Suitable habitat is present for the ringtail at all of the project sites, except at Calero Auxiliary, Rinconada Treated Water Reservoir, and Vasona dams. These sites do not provide suitable habitat since they are influenced by urbanization and/or do not support the appropriate woodland habitat. The remaining sites support suitable habitat for the ringtail in the riparian and oak woodland habitats Critical Habitat Designations One of the purposes of the Endangered Species Act (ESA) is to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved. The ESA protects habitat in many ways, including: purchasing of lands and cooperative programs with states, among others. The ESA also authorizes the designation of critical habitat. Critical habitat is defined as areas essential for the conservation of the species in question. Conservation is defined as using all means necessary to bring a species back to the point where it no longer needs the protection of the ESA. Habitat currently occupied by a listed species, may require special management considerations or protection. Critical habitat is designated on the basis of the best scientific data available, and after taking into consideration the economic impact and any other relevant impact, of designating a particular area as critical habitat. The designation of critical habitat plays several express and direct roles under the ESA. Section 7 of the ESA (16 U.S.C. 1536) dictates that each federal agency ensure that any action authorized, funded, or carried out by the agency is not likely to jeopardize the continued existence of a listed species or result in the destruction or adverse modification of... critical habitat. If an action is likely to jeopardize or result in adverse modification to critical habitat, the agency must consult with the USFWS (or the National Marine Fisheries Service if the Secretary of Commerce is the responsible Secretary). Note that under the statutory language, consultation is triggered by either jeopardy or adverse modification of critical habitat. The consultation process applies to all actions by federal agencies and to June 2011 Page 3-74

127 Section 3.3 Wildlife CHAPTER 3 all actions with a federal nexus through an approval, permit, or funding (e.g., the USACE has jurisdiction over an action), if there is reason to believe that a listed species may be present in the project area and is likely to be affected by project activities. Consultation entails study of the likely effects of project actions, a statement by the Secretary on whether jeopardy or adverse modification is found and suggestions for reasonable and prudent alternatives to the harmful aspects of the proposed project in order to avoid jeopardy or adverse modification of critical habitat. All but a few projects have proceeded under an incidental take permit that allows limited take of the listed species as an incidental part of the implementation of the project in question (Baldwin 1999). Critical habitats for the Bay checkerspot butterfly, steelhead trout, and California tiger salamander occur within the boundaries of a few of the project sites. None of the project sites are within California red-legged frog designated critical habitat. Critical habitat near the project areas is shown in Figure set III-3 in Appendix III. BAY CHECKERSPOT BUTTERFLY Critical habitat for the Bay checkerspot butterfly was first designated on April 30, 2001 (66 FR ). On August 26, 2008, the USFWS issued the final rule for modification of critical habitat for the Bay checkerspot butterfly (73 FR ). There are 15 critical habitat units for this species within Santa Clara County (all of them occur in areas with serpentine soils or geology). Critical habitat is present only within the margins of the project area at Anderson and Calero Main dams. Anderson Dam is within Unit 5 and Calero Main Dam is within Unit 8. Regardless of the location of critical habitat, suitable serpentinite grassland habitat is absent from Anderson and Calero Main dams. The project areas that are within designated critical habitat do not meet the primary constituent elements, as explained above in Section under: Special Status Wildlife Species, Bay Checkerspot Butterfly. STEELHEAD TROUT Critical habitat was designated for steelhead trout on September 2, 2005 (70 FR ). Waterways that are at least partially included in the critical habitat designation in Santa Clara County include the Guadalupe River, Pajaro River (including the Uvas and Llagas tributaries), Coyote Creek, San Francisquito Creek, Stevens Creek, and Pacheco Creek. Critical habitat is present within the boundaries of Anderson, Chesbro, Stevens Creek, and Uvas dams. Steelhead trout potentially occur downstream of all four of these dams. Other project sites outside of designated critical habitat that could potentially be reached by steelhead trout are Almaden, Coyote Percolation Ponds, Guadalupe, and Calero dams. CALIFORNIA TIGER SALAMANDER A final rule on the designation of critical habitat for the California tiger salamander was issued by the USFWS on August 9, 2005 (70 FR ). Critical habitat is present at Fellows Dike and Calero Main Dam. Both of these dams are within the same unit, East Bay Region Unit 8. Suitable breeding habitat is absent from both of June 2011 Page 3-75

128 Section 3.3 Wildlife CHAPTER 3 these project areas, with the potential for upland individuals being present considered insignificant due to the low probability of presence REGULATORY SETTING Federal Endangered Species Act The federal Endangered Species Act (ESA) protects federally listed plant and animal species as well as their habitats. Impacts to listed species resulting from the implementation of a project would require the responsible agency to consult the United States Fish and Wildlife Service (USFWS) and/or the National Marine Fisheries Service (NMFS). Section 7 of the ESA requires that all federal agencies must, in consultation with the USFWS or NMFS, ensure that the agencies actions do not jeopardize the continued existence of a listed species, or destroy or adversely modify the listed species critical habitat. Section 10 of the Act, on the other hand, authorizes issuance of take permits by USFWS/NMFS to non-federal project proponents on completion of an approved Habitat Conservation Plan (HCP). Migratory Bird Treaty Act The Migratory Bird Treaty Act makes it unlawful to take (kill, harm, harass, shoot, etc.) any migratory bird listed in 50 CFR 10, including their nests, eggs, or young. Migratory birds include geese, ducks, shorebirds, raptors, songbirds, and seabirds. Bald Eagle Protection Act The Bald Eagle Protection Act of 1940 as amended in 1959, 1962, 1972, and 1978 prohibits the taking (pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest or disturb) or commerce of bald eagles and golden eagles. Limited exceptions are listed in 50 CFR 22. US EPA List of Injunction Pesticides The Center for Biological Diversity (CBD) reached a settlement agreement with the U.S. Environmental Protection Agency (US EPA) to protect the threatened California red-legged frog (Rana draytonii) from 66 pesticides currently authorized for use in California on October 17, 2006 (US EPA 2009a). The agreement is a result of a lawsuit filed by CBD against the US EPA in The agreement, signed in October 2006, and approved by a U.S. District Court, prohibits use of these pesticides in and adjacent to core red-legged frog habitats throughout California until the US EPA completes formal consultations with the USFWS to ensure the chemicals are not jeopardizing or contributing to the decline of the species. The Court found in September of 2005 that the US EPA had violated the Endangered Species Act by registering pesticides for use without considering how they might impact the continued existence of the red-legged frog. The agreement requires the US EPA to: Complete formal consultations with USFWS on the impacts of the 66 pesticides on red-legged frogs within 3 years; June 2011 Page 3-76

129 Section 3.3 Wildlife CHAPTER 3 Prohibit interim use of the pesticides within and adjacent to red-legged frog habitats, specifically designated critical habitat areas, aquatic features and upland habitats occupied by the frog; Mandate pesticide-free buffer zones adjoining frog habitats (200 feet for aerial pesticide applications to prevent drift and 60 feet for ground applications to prevent runoff); Allow exemptions for public health vector control programs, invasive species and noxious weed programs, and other specific applications that pose little or no risk to frogs; and Distribute an educational brochure for pesticide applicators and county agricultural commissions regarding the red-legged frog, impacts of pesticides and contaminants on frogs generally, and describing the interim restrictions on pesticide use in the settlement. A second complaint was filed by CBD against the US EPA in 2007 seeking to enjoin the US EPA from authorizing use of 43 pesticides in and adjacent to core habitats and recorded occurrences of eleven additional federally listed species throughout the Greater San Francisco Bay Area Counties. This complaint was subsequently amended to include an additional 32 chemical pesticides. A stipulated settlement proposed in May 2010 prohibits full licensure for use in these areas until the US EPA completes formal consultations with the USFWS to ensure the chemicals are not jeopardizing or contributing to the decline of these species. The list of potentially affected species in this injunction and settlement includes Tidewater Goby, Delta smelt, California clapper rail, salt marsh harvest mouse, California tiger salamander, San Francisco garter snake, Alameda whipsnake, California freshwater shrimp, San Joaquin kit fox, valley elderberry longhorn beetle, and Bay checkerspot butterfly. The 2010 agreement requires the US EPA to: Complete formal consultations with USFWS on the impacts of the original list of 43 pesticides on the affected species within 2 years and the complete list by September 30, 2014, including the effects of application of a set of the urban pesticides when applied in areas with impervious surfaces; Prohibit interim use of the pesticides within and adjacent to the named species habitats, specifically designated critical habitat areas, and also additional aquatic features and upland habitats occupied by the species, described per species by the Township, Range and Section of occurrence records Mandate pesticide-free buffer zones adjoining species habitats (each species requirements are described separately but the most restrictive case includes 600 feet for aerial or ground pesticide applications); Allow exemptions for public health vector control programs, invasive species and noxious weed programs, and other specific applications that pose little or no risk to the named species; June 2011 Page 3-77

130 Section 3.3 Wildlife CHAPTER 3 Allow exemptions for certain private party uses of pesticides and certain application measures including spot treatments such as household/homeowner and indoor applications, pet collars; Allow exemptions for other outdoor uses including basal bark or cut stump application to individually treated trees where little or no risk to the named species and application occurs outside of a 60-ft. buffer to named habitat for the named species; Allow exemptions for some rodent control measures using some of the named rodenticides when use and potential wildlife exposure is controlled by use Tier 1 bait stations for application and they are used only within 10 ft. of residential or food processing structures; and Distribute an educational brochure for pesticide applicators and county agricultural commissions regarding the impacts of pesticides and contaminants on the named species generally, and describing the interim restrictions on pesticide use in the settlement and provide retailers with wildlife hazard warning labels for the named pesticides. 11 US EPA s Proposed Risk Mitigation Decision for Nine Rodenticides The US EPA has issued a proposed decision that restricts the sale and use of commercial rodenticides containing anticoagulant poisons. The US EPA proposes to: Restrict the sale and application of broadifacoum, bromadiolone, and difethialone to registered pesticide applicators; Require six other rodenticides containing anticoagulants for sale to consumers be sold in tamper-resistant bait stations; and Require labeling improvements to mitigate the risks associated with the use of these rodenticides to wildlife and children. These chemicals are currently available to consumers in common household products such as DeCon. The impact of this decision would be significant for protecting non-target wildlife from primary and secondary exposure (US EPA 2009b). The pesticides named in the court settlements described above will henceforth be collectively referred to as US EPA injunction pesticides. See Appendix XI for the collective list of US EPA injunction pesticides relative to habitat for the California red-legged frog and the California Tiger Salamander. State California Endangered Species Act The State of California Endangered Species Act (CESA) provides legal protection for plants or wildlife species listed as rare, threatened, or endangered. The California Code of Regulations Title 14 Section lists animal species considered endangered or 11 June 2011 Page 3-78

131 Section 3.3 Wildlife CHAPTER 3 threatened by the state and the California Department of Fish and Game (CDFG) maintains lists of plant and animal species designated endangered, threatened, and rare. The CDFG also maintains a list of Species of Special Concern based on limited distribution, declining populations, diminishing habitat, or unusual scientific, recreational, or educational value. Under State law, the CDFG is empowered to review projects for their potential to impact state-listed species and Species of Special Concern, and their habitats. Other Authorities Under the California Department of Fish and Game Code California Fish and Game Code governs state-designated wetlands, including riparian and stream habitat, and mandates that mitigation be implemented to replace wetland extent and value lost to development. Sections of the California Fish and Game Code regulate activities that would affect rivers, streams, or lakes by altering the flow, substantially change or use any materials from the bed, channel or bank of any river, stream or lake, or disposing of debris. Activities that affect these areas, as well as associated riparian habitats, would require a Streambed Alteration Permit from the California Department of Fish and Game. In addition, Section 3503 of the California Fish and Game Code prohibits impacts to actively nesting birds, their nests, or their eggs. Porter-Cologne Water Quality Control Act and Section 401 of the Clean Water Act The Regional Water Quality Control Board (RWQCB) administers both the Porter-Cologne Water Quality Control Act and Section 401 of the Clean Water Act. The Porter-Cologne Water Quality Control Act, Water Code Section 13260, requires that any person discharging waste, or proposing to discharge waste, within any region that could affect the waters of the State to file a report of discharge with the RWQCB. Waters of the State as defined in the Porter-Cologne Act (Water Code Section [e]) are any surface water or groundwater, including saline waters, within the boundaries of the state. Pursuant to Section 401 of the Clean Water Act, the RWQCB consider waters of the state to include but are not limited to rivers, streams, lakes, bays, marshes, mudflats, unvegetated seasonally ponded areas, drainage swales, sloughs, wet meadows, natural ponds, vernal pools, diked bay lands, seasonal wetlands, and riparian woodlands. The RWQCB has also claimed jurisdiction and exercised discretionary authority over isolated waters. Regional and Local Two Habitat Conservation Plans (HCP) efforts are underway that involve the dams of this program. They have partly overlapping action areas. These HCPs were initiated separately for different reasons but are linked by the overlap of facilities and covered activities in their respective action areas. They are being crafted in concert so that all planned covered activities and conservation elements will be compatible. The Dam Maintenance Program will be included in these two HCP efforts in accordance with the study area of each plan. June 2011 Page 3-79

132 Section 3.3 Wildlife CHAPTER 3 Three Creeks HCP The District is currently preparing the Three Creeks Habitat Conservation Plan (HCP) in order to obtain the incidental take permits pursuant to Section 10(a)(1)(B) of the Federal Endangered Species Act (ESA) from both the National Marine Fisheries Service (NMFS) and possibly, the US Fish and Wildlife Service (USFWS). These permits, if granted, would allow take of threatened and/or endangered species incidental to the otherwise lawful management activities associated with the District s operation and maintenance of its water supply facilities in three northern Santa Clara County watersheds (the Coyote Creek, Guadalupe River, and Stevens Creek watersheds, hereinafter called the Three Creeks ). The permits would apply to several District projects, including dam maintenance activities on all dams included in the DMP, except Rinconada Treated Water Reservoir, Uvas and Chesbro dams. If approved as proposed, the HCP would extend for 50 years. Conservation measures for take of covered species in the HCP would be defined in the plan. Santa Clara Valley Habitat Plan (SCV HP) The SCV HP is a cooperative effort by major Santa Clara County entities to provide an effective framework to protect, enhance, and restore natural resources in specific areas of Santa Clara County, while improving and streamlining the environmental permitting process for impacts on threatened and endangered species. The SCV-HP is being prepared as an HCP to satisfy ESA and a Natural Community Conservation Plan (NCCP) to satisfy the state Natural Community Conservation Planning Act (NCCPA). The District and partner agencies, City of San Jose, City of Morgan Hill, City of Gilroy, Santa Clara County, and the Santa Clara Valley Transportation Authority, are participating in an effort to prepare the SCV HP. To the extent that the planning areas, permit areas, and covered species of the Three Creeks HCP and the SCV HP coincide, the two plans are intended to be consistent with one another. The six partners intend that the SCV HP will allow for reasonable development, growth, and essential infrastructure construction and maintenance while accommodating the Plan s conservation goals and complying with state and federal regulatory requirements. The SCV HP includes only terrestrial species (i.e. not fish), and covers DMP activities at all the dams covered by the Three Creeks HCP (except Stevens Creek, Lenihan, and Rinconada Treated Water Reservoir dams) as well as Uvas and Chesbro dams; coverage for DMP activities at these two latter dams is not included in the Three Creeks HCP. The Draft SCV HP and associated Draft EIR/EIS were released for public comment in December of IMPACTS AND MITIGATION The DMP includes over 65 individual maintenance activities that have been grouped, for the purposes of environmental review, into three main categories based on the types of effects. The four primary categories of DMP activities are: June 2011 Page 3-80

133 Section 3.3 Wildlife CHAPTER 3 1. Surfaces work (including vegetation management, burrowing rodent control, erosion control, bank stabilization, and embankment repairs, access road and boat ramp repairs, and debris removal) 2. Maintenance of dam appurtenances and equipment 3. Inspection, monitoring, and exploratory work 4. Reservoir Dewatering, which is necessary for some activities requiring access below the water line Over the life of the DMP in the project area, it is estimated that 85% of the total project impacts will occur within the ARME, and 15% of the impacts will occur in the project area outside the ARME includes all the major facilities, such as dam faces, appurtenant structures, valves, and roads needing maintenance under the DMP; outside the ARME but still within the project area, there are a minimal number of activities, including seismic exploration and erosion control where exact footprints cannot be drawn. Because the ARME is considered to be a built and thus maintained environment, vegetation within this area will be managed or removed as a regular part of dam maintenance. Wetlands, riparian or other sensitive habitats will similarly be permanently altered or removed. Burrowing rodents will be managed and burrows will be eliminated. The geographical extent of the ARME is shown in Figure Set III-1, in Appendix III; due to the unpredictability of some of the activities (e.g. seismic exploration), it is not known exactly where the additional impacts in the APE will occur. The following sections describe the potential environmental impacts to wildlife from implementation of the DMP. Impact discussions are followed by the identification of mitigation measures, where applicable. The mitigation measures are fully described later in Section Applicable BMPs are listed for each potential impact, and presented in their complete text in Appendix V Significance Criteria Impacts to biological resources as a result of DMP activity implementation were evaluated by determining the sensitivity, significance, or rarity of each resource that could be adversely affected (either directly or indirectly) by the proposed program activities, and by using thresholds of significance to determine the significance of potential impacts. The significance threshold may be different for each habitat or species and is based upon the rarity or sensitivity of the resource and the level of impact that would result from the proposed project. The proposed project would result in a significant impact to wildlife if it would: 1. Have a substantial adverse effect, either directly or through habitat modifications, or reduce the habitat or range of special status wildlife species, or 2. Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites. June 2011 Page 3-81

134 Section 3.3 Wildlife CHAPTER 3 3. Conflict with local policies and ordinances, and any adopted HCP. POTENTIAL IMPACTS ON SPECIAL STATUS WILDLIFE SPECIES Fifteen special status animals could occur at one or more of the project sites based on information gathered from available resources, as listed in the Methods Section , above. State and/or federally listed species include: Steelhead trout California tiger salamander California red-legged frog Bald eagle California Species of Special Concern and federally Protected Species include: Chinook salmon Foothill yellow-legged frog Western pond turtle California horned lizard White-tailed kite Northern harrier Golden eagle Loggerhead shrike Tricolored blackbird San Francisco dusky-footed woodrat Ringtail None of the DMP activities would significantly impact the bald eagle. At most, wintering bald eagles would potentially perch in the trees in the vicinity of the project boundaries of Calero (Fellows Dike) and Calero Main dams. Although a nest was recently reported at Coyote Reservoir, it was not within the Coyote Dam area of potential effect. DMP activities would not impact wintering bald eagles. During onsite activities at project areas where bald eagles are present, they may perch in the abundant trees adjacent to the reservoirs and are unlikely to be disturbed by dam maintenance activities. Therefore, no mitigation is warranted because DMP activities would not impact the bald eagle. Detailed discussions of impacts are presented by species, subdivided by activity. Species such as the California red-legged frog and the California tiger salamander are analyzed in a group Steelhead Trout and Chinook Salmon OVERVIEW Salmonids (steelhead trout and Chinook salmon) could be present downstream from Almaden, Anderson, Calero Main, Guadalupe, Stevens Creek, and dams, as well as on both sides of the Coyote Percolation Ponds Dam due to the fish passage. Steelhead could be present downstream from Uvas and Chesbro dams. Anderson, Chesbro, Steven s Creek, and Uvas dams are within critical habitat for the steelhead June 2011 Page 3-82

135 Section 3.3 Wildlife CHAPTER 3 trout. The Three Creeks HCP program development is anticipating fish passage for steelhead at Almaden dam as a conservation measure which would then produce steelhead on both sides of that dam. Chinook salmon and steelhead trout in local streams are fall- and winter-run, respectively. Typically adult fish migrate and spawn in fresh water streams between early September and late April when stream flows are relatively high. Salmon enter systems in the fall with steelhead up-migration occurring from approximately January-April. Juvenile salmonids migrate out to the ocean from approximately February through May. Later season outmigration is facilitated by storm runoff events which become rarer in late April and May. Whereas the Chinook salmon juveniles hatch and rear for just a few months before the spring out-migration, juvenile steelhead trout remain in the streams year round for approximately two years. Potential impact to the steelhead trout year round or Chinook salmon during migration and spawning season could occur as a result of this project. DMP activities that could affect the tailwater reaches (activities that could cause stream turbidity or that could alter the flow regime) would be considered potentially significant. Mitigation would be implemented to avoid significant impacts. SURFACES WORK VEGETATION MANAGEMENT Hand and mechanical removal of vegetation would not have an effect on the downstream areas. The DMP includes the use of herbicides for vegetation management. Only herbicides registered for aquatic use would be used within 20 feet of waterways to prevent possible runoff of pesticides into salmonid habitat (BMP HM-8). Additionally, no herbicides on the US EPA s list of injunction pesticides would be used near creek channels, weep holes, expansion joints, etc., regardless of the presence of water (MM Wildlife-4). BMP BI-7 would be employed to minimize potential impacts to non-target organisms from the use and handling of herbicides and rodenticides (respectively). BMP BI-7 requires the application of pesticides according to all applicable regulations and product specifications. BMPs HM-1, BMP HM-7, and BMP HM-8 would be implemented to minimize impact to water quality from vegetation management and rodent control activities. These BMPs require the use of only aquatic approved (by the US EPA) herbicides in aquatic areas, the use of herbicides only in the dry season, and no application within 24 hours of rain. These BMPs prevent runoff that could pollute down-slope areas and potentially affect aquatic habitat. Grazing would not significantly impact downstream waterways. Herds would only be used periodically and for relatively short periods of time (from a few days to a week, every few months) since the dam faces are not large in size. Limited runoff from livestock excrement is expected; however, since the livestock would only remain for short periods of time, the run-off would not be so great as to impact coliform counts and other water quality parameters. The DMP requires that a Grazing Plan be prepared for any area to be maintained June 2011 Page 3-83

136 Section 3.3 Wildlife CHAPTER 3 with livestock before grazing is implemented. The plan is to include the target plant species, the species of livestock to be used, and the stocking rate and approximate grazing period for the livestock and season. These elements will be prescribed to ensure there are no adverse impacts to the area, such as overgrazing, resulting from the presence of the herd that could lead to soil erosion into aquatic habitat. With the inclusion of these BMPs and Mitigation Measures, vegetation management would not significantly impact steelhead trout or Chinook salmon. BURROWING RODENT CONTROL Burrowing rodent control activities would not significantly impact steelhead trout or Chinook salmon. Burrowing rodent control would occur in the upland areas, primarily on the dam faces, and would not be conducted in fish bearing waterways or within the vicinity of fish bearing waterways, as dictated by District policy and product application requirements (BMP HM-8). While rodenticides may also be used in baiting stations, the treated bait/grain is presented to the target rodents in a weatherized bin/tube that minimizes exposure to rain and suspends the bait above runoff and surface water transport. EROSION CONTROL, BANK STABILIZATION, AND EMBANKMENT REPAIRS Steelhead trout and Chinook salmon could be impacted as the result of erosion control, bank stabilization, and embankment repair activities at Almaden, Anderson, Chesbro, Coyote Percolation Ponds, Guadalupe, Stevens Creek, and Uvas dams if maintenance work occurred within the salmonid stream. Both steelhead trout and Chinook salmon could be impacted during migration and spawning season, with juvenile steelhead trout potentially impacted during the remainder of the year. Implementation of stream stabilization measures could require dewatering portions of the plunge pools and could require excavation and grading for installation of erosion control methods. These activities could increase downstream turbidity, which can impact the metabolism and health of steelhead trout and Chinook salmon. MM Widlife-2 will be applied if it is determined that work must occur within a potential salmonid stream; this measure requires avoidance and minimization measures, including surveys and temporary exclusionary salmonid screens, and would be required year round for steelhead trout and during the migration and spawning season for the Chinook salmon (primarily October 1 through April 30 except in years with late storm events). BMPs BI-2 and BI-3 would be implemented to reduce the potential impacts to steelhead trout and Chinook salmon from potential sedimentation impacts to a less than significant level. ACCESS ROAD AND BOAT RAMP REPAIRS Access road repairs could impact steelhead trout or Chinook salmon in areas where the road repairs occur close to streams potentially occupied by these June 2011 Page 3-84

137 Section 3.3 Wildlife CHAPTER 3 species at Almaden, Anderson, Chesbro, Coyote Percolation Ponds, Guadalupe, Stevens Creek, and Uvas dams, especially if the road repair includes stabilization, erosion repair, or grading. The species could be affected by siltation of the streams. Boat ramp repairs would not significantly impact steelhead trout or Chinook salmon. The District only maintains the boat ramps at Almaden and Guadalupe dams. County Parks maintains the boat ramps at other dams. Boat ramps are located in the reservoirs, which are upstream, away from where steelhead and salmon occur. Mitigation measure MM Wildlife 1 and BMP BI-2 would be implemented to reduce the potential impacts to salmonids to a less than significant level if activities were to extend into the streams themselves. Standard erosion control measures (refer to Section 3.4 Hydrology and Water Quality) would ensure activities would not indirectly impact any of the steelhead trout or Chinook salmon streams. TRASH AND DEBRIS REMOVAL Trash and debris removal would not significantly impact steelhead trout or Chinook salmon because such activities will not be conducted near the water, or where they could affect aquatic habitat. These activities would not impact any salmonid stream, thereby resulting in no impact to these species. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures could impact steelhead trout year round and Chinook salmon during the migration and spawning season (generally October 1 through April 30) if activities were to occur downstream from Almaden, Anderson, Calero Main, Chesbro, Guadalupe, Stevens Creek, and Uvas dams, as well as on both sides of the Coyote Percolation Ponds Dam due to the fish passage. The most significant activity that could impact salmonids would be through cessation of flows when the inlet or outlet valve is closed. A flow bypass system (MM Wildlife-1) would be implemented if the inlet/outlet valve were to be shut down long enough to result in cessation of flow downstream of the dam. MM Wildlife-1 also includes erosion control measures downstream of the dam. Long term closure of valves is covered under the dewatering section, below. Similarly, any other maintenance activities performed on dam features that would occur within a salmonid stream could impact these two species. Activities such as the seepage monitoring system repair would not impact the species as the work is located above the streams. In addition to implementing MM-Wildlife-1, the flow bypass system, MM Wildlife-2 would require surveys and relocation of salmonids found in the work area to ensure salmonids are not significantly impacted during maintenance activities. BMPs BI-2 and BI-3 would also assist to reduce the potential impacts to steelhead trout and Chinook salmon to a less than significant level. June 2011 Page 3-85

138 Section 3.3 Wildlife CHAPTER 3 INSPECTION, MONITORING, AND EXPLORATORY WORK It is unlikely that exploratory work would impact steelhead trout or Chinook salmon as these activities are typically not done in streams. However, if ground disturbances (i.e., such as trenching) were to occur within a salmonid stream, steelhead and Chinook salmon could be impacted. MM Wildlife-2 and BMPs BI-2 and BI-3 would reduce the potential impacts to steelhead trout and Chinook salmon to a less than significant level. RESERVOIR DEWATERING In the impact analysis for reservoir dewatering that follows, impacts to amphibians are also included along with impacts to fish, due to the similarity to impacts on fish. For the purposes of this DMP EIR, a programmatic analysis will be presented using the information that is available at the time of publication. While some information regarding the effects and potential mitigation measures for reservoir dewatering for north county reservoirs is available at this time, the same level of detail is not available to address impacts and mitigation for dewatering the two south county reservoirs (Chesbro and Uvas). Accordingly, impacts of reservoir dewatering at each dam will be further evaluated in a project-level CEQA analysis before the dewatering occurs. A project level CEQA review will ensue before any reservoir dewatering takes place. OVERVIEW Some elements of the DMP will require reservoir dewatering so that maintenance can occur in the area in or behind the dam. Reservoir dewatering will involve complete draining of the reservoir. Examples of activities that may require dewatering include: Modification and replacement of equipment such as inlet and outlet structures and pipes, valves, hydraulic lines or spillways. Maintenance of the reservoir pool area immediately above the dam involving removal of sediment and rock to remove materials that may affect dam operations at the inlet. Repairs to portions of the upstream side of the dam below water level. Reservoir drawdown itself will be accomplished over about 6-8 months (April through November), depending on storage and precipitation during the year prior to the maintenance work. The process of reservoir drawdown will generally be to make steady-state releases during the fall-winter to gradually reduce net reservoir storage, followed by a variable release schedule for March through May. In all cases reservoir drawdown flows will be ramped to minimize rapid fluctuations in water depth and area of wetted channel. Ramping involves controlled, incremental increases or decreases in water releases at the dam outlets so as to minimize impacts that might otherwise occur under large changes in flow rates. June 2011 Page 3-86

139 Section 3.3 Wildlife CHAPTER 3 It is anticipated that every reservoir will require dewatering an average of approximately 4 times per 50 year period. Within this system-wide limit, the number of dewaterings per reservoir will vary. For example, there may be more than 4 dewaterings at one reservoir and fewer than 4 at another. It is anticipated that each dewatering would extend through one summer, except for Anderson, the District s largest reservoir, which would require two summers of dewatering because of its larger scale in comparison with the other dams and reservoirs. POTENTIAL IMPACTS OF DEWATERING When reservoirs are dewatered for necessary dam maintenance, the dewatering creates (a) sustained high flows as the reservoir is drained and (b) sustained very low flows when the reservoir is empty or refilling. These changes in flow have the potential to affect the following species: Steelhead, Chinook salmon, California red-legged frog, foothill yellow-legged frog, as described below. Potential Impact 1: Impact of Flows Needed to Drain the Reservoirs In order to prepare the dam for maintenance during the summer, water would need to be released during spring at higher rates than normal. These consistently higher flows during dewatering could flush juveniles, eggs, and larvae downstream, into stream reaches where the habitat conditions such as temperature, presence of predators, or lack of cover are not conducive to survival. In addition, fish and tadpoles that were swept downstream could become stranded when flows are reduced as the reservoir dries out. It is estimated that the length of channel affected by flows 50% greater than winter base flows would be 25.5 miles for Coyote Creek, and that flows of this magnitude could have significant flushing effects on aquatic organisms. Stevens and Guadalupe watersheds would not be affected because of the smaller amounts of water stored in the reservoirs. Dewatering Chesbro and Uvas reservoirs may cause similar impacts, although insufficient information is available to determine the full extent of the potential effects. Potential Impact 2: Effects of Lower Than Normal Flows When the reservoirs are dewatered, the main source of flow to the downstream aquatic habitat would be removed, although tributaries below the dams would still supply a minimal amount of flow. Thus, the ability of downstream channels to support fish and amphibians during the period of maintenance and while the reservoirs are refilling would be significantly reduced. These events could stress populations of fish and amphibians. In extreme cases, a population could decline to the point where it would not recover. Steelhead and frogs could be adversely affected; Chinook salmon are not as likely to be affected because they will rear and emigrate once they reach the downstream reaches. The length of channel affected by lower than normal flows under average conditions is June 2011 Page 3-87

140 Section 3.3 Wildlife CHAPTER 3 as follows: Coyote Creek, 10.4 miles; Guadalupe Watershed, 16.4 miles, and Stevens Creek, 3.8 miles. Insufficient information is available at this time to determine channel length impacts from dewatering Chesbro and Uvas reservoirs. Potential Impact 3: Introduction of Non-Native Organisms The reservoirs contain ample quantities of non-native fish and amphibians. Dewatering prior to maintenance may allow these non-native fish and amphibians to enter the channels downstream of the dam. The introduction of these non-native organisms has the potential to increase predation and competition for native fish and amphibians, thereby threatening their populations. The potential impacts and biological objectives for the mitigation measures are summarized in Table below. MITIGATION MEASURES FOR DEWATERING IMPACTS Mitigation Measures General-1, 2 and 3 provide for project-level review and consultation, ramping, supplemental water and protective measures to address the movement of non-native fish and amphibians from reservoirs into downstream channels. Mitigation Measures General-1 and 2 ensure that prior to approval of any dewatering, a project-level environmental review will be conducted to analyze impacts and mitigation measures and the District will coordinate with resource agencies for individual reservoir dewatering projects. Mitigation Measure General 3 requires development of a Reservoir Specific Dewatering Plan to provide for ramping, supplemental watering and non-native species measures. Ramping reduces the high level flows to the extent feasible thereby reducing impacts on downstream reaches. Supplemental water supplies during periods when reservoirs are dewatered would increase the level of protection for populations of steelhead, California red-legged frogs, and foothill yellow-legged frogs that may rear below the major dams. The objective of the supplemental flows is to the extent feasible to supply the quantity and quality of water that would otherwise be available. For any locations where adequate quantity and quality of water to fully support downstream aquatic organisms is not available, the District would develop additional provisions for fish rescue and feeding programs to support fish metabolism. Table 3.3-2, below, provides a summary of potential supplementary water sources during dam dewatering events. A complete analysis of these mitigation measures and any residual impacts after implementation shall be provided in a project-level analysis. June 2011 Page 3-88

141 Section 3.3 Wildlife CHAPTER 3 Table 3.3-2: Potential Sources of Supplemental Water (*now in place) Potential Supplemental Reservoir Sources of Water Coyote Anderson Calero Almaden Guadalupe Lexington Stevens Creek Chesbro Uvas 1. Bypassed inflow 1. Bypassed inflow 2. Coyote Reservoir 3. Santa Clara Conduit* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Almaden Valley Pipeline* 1. Bypassed inflow 2. Well-pipeline system 1. Bypassed inflow 1. Bypassed inflow Screening and trapping provisions for non-native species would reduce impacts from non-native species moving from reservoirs to downstream reaches. These measures would be expected to reduce the potential effects of reservoir dewatering on wildlife. However, based on the presence of special status species in downstream reaches and uncertainties regarding the details of a project-level analysis and the feasibility and effectiveness of future mitigation measures, it is not known if the proposed programmatic measures and/or future measures would reduce impacts to less than significant. Accordingly, for purposes of this programmatic analysis, dewatering has potentially significant and unavoidable impacts on wildlife. June 2011 Page 3-89

142 Section 3.3 Wildlife CHAPTER 3 Table 3.3-3: Summary of Impacts and Mitigation Measures for Reservoir Dewatering Impact Impact 1: Consistently higher flows during dewatering may flush juveniles, eggs, and larvae downstream (Steelhead, Chinook salmon, California red-legged frog, foothill yellow-legged frog) Impact 2: Low flows following reservoir dewatering may dry the stream and strand fish and amphibians (Steelhead, Chinook salmon, California red-legged frog, foothill yellow-legged frog) Component of MM General-3 Ramping Supplemental Water Program Biological Objectives of Mitigation Measure a. Maintain stable breeding and rearing conditions in the channels during dam dewatering by keeping flow as close to winter base flows as is feasible. b. As dewatering ends, and low flows begin, provide a period of continuous flow over critical riffles and other barriers to allow upstream movement of covered aquatic species as the channel dries back. a. Supplemental water systems will sustain downstream populations of fish and amphibians. Impact 3: Dewatering prior to maintenance may allow non-native fish and amphibians to enter the channels downstream of the dam, and this may increase predation and competition. (Steelhead, Chinook salmon, Pacific lamprey, California red-legged frog, foothill yellow-legged frog, California tiger salamander) Prevent Non-Natives from Entering Stream During Dewatering a. Ensure that exotic species in the reservoir do not escape to the downstream channel. b. Protect in-reservoir native species. c. In any stream where reservoir dewatering effects on summer flow are not fully offset by supplemental water system flows, maximize channel carrying capacity for native species during periods following reservoir dewatering by reducing populations of exotic species in the system by trapping and disposing of bull frogs and other nuisance species during reservoir dewatering California Tiger Salamander, California Red-Legged Frog, Foothill Yellow-Legged Frog, and Western Pond Turtle OVERVIEW As is explained below, data collected during burrow excavations on the dam faces have not shown that any of the burrows are being used by any listed species. However, potential upland habitat in the form of rodent burrows on the dam faces could offer refugia for the California tiger salamander and the California red-legged frog. The foothill yellow-legged frog (a stream dwelling amphibian) and the western pond turtle are not known to use burrows as refugia. The total acreage of potential upland habitat that could be affected is 51 acres for the California tiger salamander June 2011 Page 3-90

143 Section 3.3 Wildlife CHAPTER 3 and 65 acres for the California red-legged frog; these are overlapping acreages. Potential upland habitat impacts are calculated as the entire land area of the ARME, in addition to accounting for 15% impacts that could occur outside the ARME, for all dams where the California red-legged frog and California tiger salamander could occur. The District will provide mitigation for these impacts through compensation defined in MM Widlife-3. The western pond turtle and the foothill yellow-legged frog have the potential to occur within the aquatic habitat of the project area, with the exception of Rinconada Treated Water Reservoir Dam. Potential impacts to the foothill yellow-legged frog and the western pond turtle habitat, however, would be less than significant with mitigation, as described below. Table 3.3-4, below, summarizes the locations for potential habitat impacts for the four species discussed above. Table 3.3-4: CRLF/CTS/FYLF/WPT Presence at Dams CRLF=California Red-Legged Frog CTS=California Tiger Salamander FYLF=Foothill Yellow-Legged Frog WPT=Western Pond Turtle P = Present PT = Potential, nearby records, habitat available OT = Occasional transient NR = No CNDDB Record NH = No Habitat for all life history stages or no connectivity to habitat to complete life history EXT = Presumed extirpated per USFWS 1998 FACILITY CRLF CTS FYLF WPT Coyote Creek Coyote Dam P OT P P Anderson Dam NR/NH PT PT P Coyote Percolation Ponds Dam PT NH PT P Calero Creek Fellows Dike NR/NH PT NR/NH P Calero Aux Dam NR/NH PT NR/NH P Calero Main Dam PT PT NR/NH P Alamitos Creek Almaden Dam PT NR/NH OT P Guadalupe Creek Guadalupe Dam PT OT PT P Los Gatos Creek Lenihan Dam PT NR/NH NR/NH P Vasona Dam EXT NR/NH NR/NH OT June 2011 Page 3-91

144 Section 3.3 Wildlife CHAPTER 3 FACILITY CRLF CTS FYLF WPT Stevens Creek Stevens Creek Dam OT NR/NH NR/NH PT Uvas Creek Uvas Dam PT NR/NH OT P Llagas Creek Chesbro Dam OT NR/NH OT P In spite of the possible presence of these species in the project area, site investigations of burrows in the project area have yielded very little evidence of presence. In 2010 the District received authorization from USFWS to perform burrow excavation; data collected indicated no special-status species observations in any burrow on any dam during inspections of 760 burrows on six dams in 43 working days from February 16 to April 22, 2010 (SCVWD 2010). Additional data include the following: Non-special-status amphibian and reptile species observed in burrows and crevices on Phase II dams were 4 arboreal salamanders, 4 California newts, 11 Pacific chorus frogs, 6 California slender salamanders, 12 western fence lizards, 13 western toads, 1 gopher snake, and 2 western skinks. Many of these amphibians and reptiles were in torpor. Individuals were found in ground squirrel, mole/gopher, or vole burrows. The California newts and several of the western toads were found outside burrows or just inside the entrances to burrows; these animals were likely moving through the Project areas. The apparent lack of use of burrows by special status amphibians could be a function of the limited habitat offered by the burrows; the overall length and depth of the burrows were limited by the compacted material of the dams. The Burrow Investigation Report states that: Overall, burrows on all of the dams exhibited a clear, consistent pattern whereby those burrows that were long were not deep, and those burrows that were deep were short. This pattern is likely due to the fact that the hard, compacted fill beneath the topsoil on the dams prevents burrowing mammals from establishing extensive, deep burrows. All long burrows occurred near the surface; burrows that were deeper ended abruptly. Thus, the majority of the excavation on the dams that occurred as a result of burrowing mammals was within the top 2 ft of the surface of the dam faces (SCVWD 2010). Western pond turtles are an aquatic species; however, they may occur on the dam faces when laying their eggs or hibernating. During the burrow excavation activities of 2010, no western pond turtles were observed on the dam faces, although one western pond turtle carcass was found in boulders on the lower third of the downstream face of Almaden Dam. Several pond turtles were observed basking in the pond below the downstream face of Chesbro Dam. Pond turtle nests do not incorporate small mammal burrows (SCVWD 2010). Foothill yellow-legged frogs are stream dwelling amphibians, spending most or all of their life in or near streams. The burrow investigations did not reveal the presence of any foothill yellow-legged frogs on the dam faces, nor is it expected. June 2011 Page 3-92

145 Section 3.3 Wildlife CHAPTER 3 SURFACES WORK VEGETATION MANAGEMENT Mechanical removal of vegetation includes removal of vegetation and vegetation trimming using hand tools, or other machinery without application of herbicide. Mechanical removal of vegetation is not expected to impact California tiger salamander, California red-legged frog, foothill yellow-legged frog or western pond turtle because it would be performed in upland areas without disrupting subsurface layers, and application of MM Wildlife-7 would require pre-activity surveys as well as avoidance if any individuals are found. Thus, these activities would not significantly impact habitat or result in the compaction of burrows. The use of herbicides could potentially impact amphibians (and their breeding). Mitigation measure MM-Wildlife-4 would be applied to this activity to restrict the use of herbicides on the US EPAs injunction list so as to avoid impacts to these sensitive species. The US EPA injunction pesticides are listed in Appendix XI. The implementation of BMPs HM-1, HM-7, and HM-8 would also serve to avoid potential impacts of herbicide use to these species. Grazing is recognized as an activity that is compatible with the life history of these organisms and would not result in any significant impacts, especially after application of MM Wildlife-7, which requires that grazing be restricted to the dry season, when amphibians are not normally present. BURROWING RODENT CONTROL Burrowing rodent control activities could potentially impact these species. The use of anticoagulants such as chlorophacinone and diphacinone and fumigants where individuals could be present, and the placement of rodenticides directly in burrows where salamanders or frogs could be seeking refugia in upland habitats, could impact these species as per the list of rules and regulations for the species in the Federal Register, Vol. 69, No Chlorophacinone is listed as an injunction pesticide within California tiger salamander habitat, and strychnine is listed as an injunction pesticide within both California red-legged frog and California tiger salamander habitat. California tiger salamanders, California red-legged frogs, and foothill yellow-legged frogs would likely have similar reactions to chlorophacinone and strychnine. The western pond turtle is confined to eating while in the water, so would not be affected by rodenticides, which are only applied in upland areas. Therefore, the US EPA s requirements for the California red-legged frog would also be implemented for the California tiger salamander and foothill yellow-legged frog during maintenance activities through application of MM Wildlife-4. Under MM Wildlife-4, rodenticides on the US EPAs list of injunction pesticides would not be used at any project area where California tiger salamander, California red-legged frog, or foothill yellow-legged frog could occur (see Table 3.3-4). Baiting through the use of zinc phosphide would be restricted to once per year during the summer at the entrance to burrows; during the baiting period the June 2011 Page 3-93

146 Section 3.3 Wildlife CHAPTER 3 entrance to the burrows would be blocked thereby preventing access from the outside. After the baiting period the bait would be deactivated through contact with water. These measures in the form of MM Wildlife-11, Pesticide Impact Reduction, would prevent contact of this bait with these species, and reduce potential impacts to a level of non-significance. Live trapping methods could entrap non-target species, such as listed amphibians (frogs) or western pond turtles. These animals could be harmed if they were trapped away from heat, shade, and/or a water source in a live trap. MM Wildlife-5 requires that trapped individuals be safely released, and that traps be stocked with water, fleece for warmth, and shade to avoid significant impacts. Kill trapping methods could result in harm to non-target species such as listed amphibians (frogs) or western pond turtles; the likelihood of harm to these species is low due to the suspected low occurrence on the dam faces. MM Wildlife-3 would provide the compensatory mitigation for unavoidable harm to the California tiger salamander, California red-legged frog, and western pond turtle associated with trapping, and would reduce impacts to a level of non-significance. Suitable upland habitat for the California tiger salamander and California red-legged frog could be lost by elimination of burrows. It is not expected that yellow legged frogs or pond turtles would use the burrows as habitat. Secondary or low use (aquatic or riparian habitat near dams) habitat for yellow legged frogs and potential nesting habitat for pond turtles could be lost through compaction or track walking methods (i.e. driving heavy tracked vehicle over surface to collapse and compact burrows). Collapse of burrows through hand compaction methods or track walking could also harm individual California tiger salamanders, California red-legged frogs and pond turtle eggs where these species have potential to occur. Mitigation for burrow elimination will be applied to compensate for potentially significant impacts to these species habitats and potential harm to individuals as described in MM Wildlife-3. Until such time as when the appropriate wildlife agencies issue take permits for DMP impacts to the California tiger salamander and California red-legged frog, hand methods described in mitigation measure MM Wildlife-6 will be employed for burrow elimination in order to minimize the potential for harm to individuals; this mitigation measure will also use prior scoping with a burrow camera in burrows where these species could be present. After the appropriate wildlife agencies have issued take permits for DMP impacts to the California tiger salamander and California red-legged frog, monitoring through the use of a burrow camera will not be used for burrow elimination because MM Wildlife-3 will compensate for both habitat loss and the potential sink effect of harm to individuals. Because pond turtle eggs are nearly impossible to find, avoidance during burrow elimination is not practicable. The loss of pond turtle eggs and potential pond turtle nesting habitat, and secondary habitat for yellow-legged frogs, would be compensated for as described in MM Wildlife-3. With mitigation, the potential impacts to California tiger salamanders, California red-legged frog, foothill yellow-legged frog and western pond turtles would be less than significant. June 2011 Page 3-94

147 Section 3.3 Wildlife CHAPTER 3 EROSION CONTROL, BANK STABILIZATION, AND EMBANKMENT REPAIR Erosion control, bank stabilization, and embankment repair activities could potentially impact California tiger salamanders, California red-legged frogs, foothill yellow legged frogs, and western pond turtles. The most likely activities that could impact this species is if erosion control or embankment repair activities occur along the dam faces where burrows are present, potentially impacting CTS and CRLF, or if measures are implemented that impact the potential breeding pool at the base of the Calero Auxiliary Dam, potentially impacting all four species. The introduction of sediment into a breeding pool could adversely affect hatching and breeding conditions such as oxygen availability. These activities would serve to stabilize the dam slopes and reduce erosion, which will reduce the potential for sediment introduction into the breeding pool at the base of Calero Auxiliary Dam. MM Wildlife-7, which requires surveys and avoidance at sites where these species may be present, reduces the potential impacts due to erosion control, bank stabilization, and embankment repair activities to a less than significant level, in conjunction with MM Wildlife-3, which includes compensation mitigation for loss of burrows for California tiger salamander and California red-legged frog habitat. With mitigation, the potential impacts to California tiger salamanders, California red-legged frog, foothill yellow-legged frog and western pond turtles would be less than significant. ACCESS ROAD AND BOAT RAMP REPAIRS Access road repairs are not anticipated to impact the pool at the base of the Calero Auxiliary Dam where California tiger salamanders may be breeding due to the distance between any roadway and the pool. However, access road repairs could permanently impact suitable upland habitat for the California tiger salamander, as well as for California red-legged frogs by filling burrows or removing suitable rock or wood piles alongside the roadways at Anderson and Calero Auxiliary dams. Access road maintenance could also impact foothill yellow-legged frogs, and western pond turtles if activities were to occur within or near the downstream riparian and aquatic habitat (for all four species) or adjacent to the reservoirs (for the western pond turtle). Access roads are located near the suitable habitat for these species at all of the dams except Rinconada Treated Water Reservoir Dam. Repairs to many of these roads, particularly roads that occur within the riparian habitat up to the plunge pools or outlets downstream from the dams, could result in impacts to these species. Access road repairs that occur within suitable habitat for these species could potentially crush or injure individuals with equipment or destroy burrows where frogs or California tiger salamanders are seeking refugia. However, these activities would not significantly impact these species after implementation of MM Wildlife-7. June 2011 Page 3-95

148 Section 3.3 Wildlife CHAPTER 3 Boat ramp repairs would not significantly impact the California tiger salamander, California red-legged frog and foothill yellow-legged frog. The District only maintains the boat ramps at Almaden and Guadalupe dams with County Parks maintaining the boat ramps at other dams. Boat ramps are located in the reservoirs, which are upstream, away from where these species would occur. Boat ramp repairs could impact the western pond turtle at Almaden and Guadalupe dams. However, boat ramp repairs would not significantly impact these species after implementation of MM Wildlife-7. MM Wildlife-7 requires pre-activity surveys, as well as avoidance and relocation measures reducing the potential impacts to CTS, CRLF, CYLF and WPT individuals to a less than significant level. Additionally, erosion control measure BMP WQ-41 would ensure activities would not indirectly impact the suitable breeding pond at Calero Auxiliary Dam. Compensation for any impacts to habitat such as loss of burrows would be mitigated through compensation defined in MM Wildlife-3. With mitigation, the potential impacts to California tiger salamanders, California red-legged frog, foothill yellow-legged frog and western pond turtles would be less than significant. TRASH AND DEBRIS REMOVAL Trash and debris removal would occur most commonly on dry, ruderal ground adjacent to existing facilities, within concrete spillways, or along the reservoir shorelines. Trash and debris piles would only be staged on disturbed areas and would be removed immediately so as to avoid the possibility of colonization by these wildlife species (Wildlife MM-7). Impacts on CTS, CRLF, CYLF and WPT resulting from trash and debris removal would be less than significant, with mitigation. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Due to the limited locations of appurtenance structures, the potential impact of maintenance of appurtenant structures is confined to rather small geographical areas. Potential impacts to the species in this section as a result of maintenance activities such as block house repairs, and piezometers repairs would be addressed by mitigation measure MM Wildlife-7, which includes monitoring for species presence, avoidance and relocation if necessary. Amphibians, reptiles and small mammals are regularly found in weep holes and expansion joints that serve as cover sites/refugia, (i.e., those weep holes or expansion joints that are not occluded with soil and debris). Sensitive species, including California red-legged frog, foothill yellow-legged frog, and California tiger salamander, as well as other wildlife, could occur in weep holes and expansion joints and may be killed or injured during cleaning or repair of these structures. Application of herbicide to vegetation growing in expansion joints or other locations has the potential to affect amphibians that could be seeking refuge there. Avoidance of adverse effects on wildlife in weep holes and expansion joints would be implemented by MM Wildlife -8 which requires that weep holes and expansion joints be searched June 2011 Page 3-96

149 Section 3.3 Wildlife CHAPTER 3 for wildlife by a qualified biologist on the day of maintenance to ensure that no wildlife will be harmed by the cleaning or repair. MM Wildlife-8 describes the procedure for biological surveys for weep hole and expansion joint maintenance to minimize killing or injuring wildlife that are found in the weep holes and to potentially significant impacts to special status species that could occur in the weep holes. Application of MM Wildlife-4 to restrict the use of herbicides on the US EPAs injunction list would avoid impacts to these sensitive species. The injunction pesticides are listed in Appendix XI. Maintenance of appurtenant structures such as seepage monitoring systems or outlet structures could impact the California red-legged frog, foothill yellow-legged frog, and western pond turtle. Frogs and turtles could be crushed or otherwise injured by equipment, especially when working on the outlet structure, or seepage monitoring weirs, if they are located in potential habitat. MM Wildlife-7, which includes monitoring for species presence, avoidance and relocation if necessary, would be implemented to minimize effects to these species. Altering the seepage monitoring systems could potentially reduce suitable aquatic habitat for these species. If aquatic habitat is reduced compensatory habitat would be provided through MM Wildlife-3. Shutting of the inlet/outlet valve could cause cessation of downstream flows; however, a flow bypass would be used for shutdowns that would otherwise cause an interruption of downstream flow. Flow bypass systems would ensure water flow to downstream areas, sufficient to minimize effects on California red-legged frog, California tiger salamander, foothill yellow-legged frog, and western pond turtle to less than significant levels (MM Wildlife-1). This mitigation measure would also include erosion control measures that would be implemented to prevent scour at the point of entry of the flow bypass pipe, to prevent adverse effects to these species. INSPECTION, MONITORING, AND EXPLORATORY WORK Exploratory work in the project area could impact California tiger salamander, California red-legged frog, foothill yellow-legged frog and/or western pond turtles through destruction of habitat and direct impacts from machinery such as heavy vehicles or drill rigs. For example, if exploratory work impacts the pool at the base of the Calero Auxiliary Dam or permanently impacts suitable upland habitat for the California tiger salamander (i.e., result in the filling of burrows or removal of suitable rock or wood piles), California tiger salamanders would be impacted. Mitigation measure MM Wildlife-7 would be required to avoid impacts to each of these species and MM Wildlife-3 would be implemented for any loss of habitat. With mitigation, the potential impacts to California tiger salamanders, California red-legged frog, foothill yellow-legged frog and western pond turtles would be less than significant. Inspections and monitoring are not anticipated to impact these species; only exploratory work that requires ground disturbance would pose an impact. June 2011 Page 3-97

150 Section 3.3 Wildlife CHAPTER 3 RESERVOIR DEWATERING Discussed above, under Steelhead Trout and Chinook Salmon California Horned Lizard SURFACES WORK, MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT AND INSPECTION, MONITORING, AND EXPLORATORY WORK The horned lizard could potentially occur in the project area on dry, upland locations at any of the dam sites except Rinconada Treated Water Reservoir Dam. Project activities could cause harm or injury to the lizard if it is crushed or injured by vehicles or machinery, trampled by livestock, or injured by heavy equipment during burrow elimination, maintenance of dam appurtenances or exploratory work. Mitigation measure MM Wildlife-9 would be implemented to minimize effects to the lizard to less than significant levels. The measure includes conducting pre-project biological surveys for presence and avoiding if present or relocating individuals if they cannot be avoided White-Tailed Kite, Northern Harrier, Golden Eagle, Loggerhead Shrike, and Tricolored Blackbird (as well as migratory birds) OVERVIEW The white-tailed kite, northern harrier, golden eagle, loggerhead shrike, and tricolored blackbird are protected by virtue of their regulatory status and under the Migratory Bird Treaty Act. This Act makes it unlawful to take (kill, harm, harass, shoot, etc.) any migratory bird listed in 50 CFR 10, including their nests, eggs, or young. To that end, migratory bird species are protected while nesting according to this Act, including raptor species such as red-tailed hawks (Buteo jamaicensis) and red-shouldered hawks (Buteo lineatus), and colonial species such as cliff swallows (Petrochelidon pyrrhonota) and barn swallows (Hirundo rustica). All migratory birds, including raptors and passerines, are protected by the Migratory Bird Treaty Act. The golden eagle is also protected under the Bald Eagle Protection Act which prohibits the taking of (pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest or disturb) or commerce in bald eagles and golden eagles. Potential habitat used by protected nesting migratory birds is present within all of the project boundaries. It is unlikely that the golden eagle would nest at the Coyote Percolation Dam, Rinconada Treated Water Reservoir Dam, or Vasona Dam due to urbanization in those areas. Ground nesting birds, including northern harriers, tricolored blackbirds, and other migratory species, could be breeding in the large wetland at the base of the Calero Main Dam. The colonial nesting swallows utilize man-made structures at the project sites for nesting, such as the spillway weep holes June 2011 Page 3-98

151 Section 3.3 Wildlife CHAPTER 3 (Santa Clara Valley Audubon Society, 2010b) and blockhouses, and are also known to use the historic Bailey-Fellows house adjacent to Fellows Dike 12. Overall, DMP activities could potentially impact a number of migratory birds, particularly if work were to occur during their nesting season (generally February 1 through August 31). Impacts to these species during DMP activities would be less than significant with implementation of MM Wildlife-10 (requiring establishment of buffers around active bird nests) and BMPs BI-8 (pre-activity surveys and avoidance) and BI-9 (placement of nesting exclusion devices in advance of the nesting). SURFACES WORK VEGETATION MANAGEMENT Vegetation management activities can generate loud noises, or directly alter the nesting areas of sensitive avian species and other migratory birds, particularly with the removal of trees. Any vegetation management activity that disrupts nesting or removes active nests (i.e., noise/vibration within 50 feet of tree/shrub nests, or 250 feet of raptor nests; removal of trees or shrubs; cleaning weep holes utilized by swallows) would be considered a significant impact on these species. BMP BI-8 and mitigation measure MM Wildlife-10, which requires a buffer around active nests, would be required to reduce potential impacts to avian species to less than significant levels. BURROWING RODENT CONTROL Burrowing rodent control activities are not expected to significantly impact protected bird species. BMP BI-7 would minimize the bioaccumulation of rodenticides by requiring removal of carcasses of poisoned animals, when they are found. This BMP would minimize potential secondary toxic effects on raptors or other wildlife. Carcass survey and disposal would be performed in the treated area beginning on the third day following the initial exposure of toxic baits. Any exposed carcasses would be disposed of in a manner inaccessible to wildlife. Baiting through the use of zinc phosphide would be restricted to once per year during the summer at the entrance to burrows; during the baiting period the entrance to the burrows would be blocked thereby preventing access from the outside. After the baiting period the bait would be deactivated through contact with water. These measures in the form of MM Wildlife-11, (Pesticide Impact Reduction), would prevent contact of this bait with these species, and reduce potential impacts to a level of non-significance. The loss of a small amount of prey base available to predatory avian species resulting from the burrowing rodent control measures is not considered significant due to the abundance of available prey in the surrounding areas. All 14 dams total approximately 360 acres of suitable foraging habitat in the County. In comparison, the available foraging area for predatory birds in the 12 As observed during site visits conducted between February 2006 and June 2007 June 2011 Page 3-99

152 Section 3.3 Wildlife CHAPTER 3 study area of the Valley Habitat Plan, a subset of Santa Clara County, but inclusive of most of the DMP project area, has been estimated to be approximately 396,000 acres (Santa Clara County 2010, Table ES-2). The reduction of this small amount of overall foraging habitat in 14 locations scattered throughout the County, for which abundant suitable habitat would remain available following burrowing rodent control activities, would not significantly impact predatory bird species. Bait could significantly impact migratory bird species. Seed eating birds may ingest the bait and succumb to poisoning. Bait stations and scatter baiting provide access to baited seeds that birds may consume. Poisoning of migratory birds is a potential significant impact. MM Wildlife-11 requires that bait stations be modified to as to reduce access to non-target species including migratory birds; MM Wildlife-4 requires that rodenticides would not be applied as scatter bait unless re-licensed for such purposes. EROSION CONTROL, BANK STABILIZATION, AND EMBANKMENT REPAIRS, ACCESS ROAD AND BOAT RAMP REPAIRS, TRASH AND DEBRIS REMOVAL These activities could potentially impact protected migratory bird species, particularly if work were to occur during their nesting season (February 1 through August 31). Any activity that results in noise/vibration within 50 feet of tree/shrub nests, or 250 feet of raptor nests, or removal of trees or shrubs may impact these species. Open gravelly areas, such as roads and turn-around areas, trees or large shrubs, weep holes (utilized by swallows), or the large wetland at Calero Main Dam are examples of known habitats in the project areas for nesting migratory birds. BMPs BI-8, BI-9, and BI-10 and MM Wildlife-10, which requires a buffer around active nests, would be required to reduce potential impacts to white-tailed kites, northern harriers, golden eagles, loggerhead shrikes, and tricolored blackbirds (as well as nesting migratory birds) due to erosion control, bank stabilization, embankment repairs, access road and boat ramp repairs and trash and debris removal to a less than significant level. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT AND INSPECTION, MONITORING, AND EXPLORATORY WORK Maintenance of dam appurtenances and equipment and exploratory work could potentially impact listed and non-listed migratory bird species, particularly if work were to occur during their nesting season (February 1 through August 31). Weep hole cleaning and repair may directly affect migratory bird species nesting in the weep holes, a significant impact. Filling of cavities behind the weep holes will be confined to the voids behind the weep hole, and would therefore reduce potential for nesting opportunities within the weep hole itself. Any activity that results in unusual loud noises or utilizes heavy equipment within 50 feet of a tree/shrub active migratory bird nest, or 250 feet of an active raptor nest or removes nesting habitat June 2011 Page 3-100

153 Section 3.3 Wildlife CHAPTER 3 itself such as trees or large shrubs, cleaning of weep holes (which provide nesting sites), may impact these species. BMPs BI-8, BI-9, and BI-10 and MM Wildlife-10 and MM Wildlife-8 would be implemented to reduce potential impacts to white-tailed kites, northern harriers, golden eagles, loggerhead shrikes, and tricolored blackbirds, as well as nesting migratory birds, during maintenance of appurtenant structures to a less than significant level San Francisco Dusky-Footed Woodrat OVERVIEW San Francisco dusky-footed woodrat nests are currently present within the project boundaries of Almaden, Anderson, Calero Main, Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, and Uvas dams (see Figure Set III-4 for maps showing woodrat nest locations in Appendix III). Although their nests are located in woodland or chaparral, woodrats will disperse on grassland and other areas such as dam faces and in proximity to access roads. Impacts to this species during DMP activities would be considered potentially significant. Mitigation is defined below and would reduce impacts to a level of less than significant. SURFACES WORK VEGETATION MANAGEMENT Vegetation management within chaparral or woodland habitat, particularly the initial removal of large, mature trees where woodrat nests exist, or at any dam where woodrats may occur in the future, could potentially result in significant impacts. Woodrats typically habituate easily to various levels of noise disturbance including vehicular traffic; loud noises from chain sawing or grading would not have a significant impact on woodrats as long as their microhabitat is not actually changed. Noise is not expected to have a significant impact on woodrats as long as the woodrats have their original overstory for shade, their cover and food resources are intact, and structural logs supporting their nest are not moved or touched by heavy equipment. Vegetation removal (mechanical or livestock grazing) in the vicinity of woodrat nests could cause woodrats to abandon the nests which would be considered a potentially significant impact on the species. Acreages of woodland within the project area are shown below in Table June 2011 Page 3-101

154 Section 3.3 Wildlife CHAPTER 3 Table 3.3-5: Characterization of Vegetation Management Impacts to Oak and Conifer Woodlands Location Almaden Dam Anderson Dam Calero Fellows Coyote Main Dam Guadalupe Dam Lenihan Dam Stevens Creek Dam Uvas Dam Vasona Dam TOTAL Natural Community Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Foothill Pine Oak Woodland Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Coast Live Oak Woodland and Forest Foothill Pine Oak Woodland Acreage within ARME Acreage Beyond ARME, But Still Within the Project Area 0.93 ac 3.54 ac 0.13 ac 0.10 ac 3.80 ac 0.82 ac 0.05 ac 1.19 ac 1.67 ac 6.32 ac 0.51 ac 4.00 ac 0.50 ac 0.45 ac 0.18 ac 3.39 ac 0.64 ac 4.80 ac 0.63 ac 0.96 ac 5.24 ac 0.1 ac ac 0.82 ac If intensive vegetation management activities occur within or immediately adjacent to suitable habitat (i.e., chaparral or woodland habitats), mitigation measure MM Wildilfe-12 would be required, reducing the impacts on San Francisco dusky-footed woodrats to a less than significant level. This measure includes avoidance, survey work, relocation, and monitoring, as well as replacement of woodland habitat at a ratio of 3:1. Potential impact from herbicide use will be avoided by application of MM Wildlife-11 which requires that: herbicides will not be sprayed within 155 feet of woodrat nests in order to avoid unintended impacts such as drift to nearby nests; and that the cut stump method of herbicide application (without a spraying mechanism) will not be used within 10 feet of woodrat nests. BURROWING RODENT CONTROL Burrowing rodent control activities could potentially impact San Francisco dusky-footed woodrats. While burrowing rodent control activities would be focused upon target species, small numbers of non-target species, such as the San Francisco dusky-footed woodrat, could be impacted when utilizing poison bait or live trapping. If woodrats are accidentally trapped in live traps, they June 2011 Page 3-102

155 Section 3.3 Wildlife CHAPTER 3 could be adversely impacted. With implementation of MM Wildlife-5, effects would be less than significant. The measure requires release of trapped woodrats and the stocking of traps with fleece, water, and shade to prevent injury from exposure. This measure also requires that kill traps shall be buried in burrows so as to minimize possible harm to non-target species at ground level. The use of other rodent control methods, such as fumigants, (which will only be applied within a burrow) would not impact this species because they are not found in burrows. Scatter baiting will only be used if regulations permit and if special status species are not likely to be present (see MM Wildlife-4 for more details on this). Modified bait stations will otherwise be used as long as the stations are located at least 155 feet from woodrat nests or are capped nightly so that woodrats are not exposed to the bait in accordance with MM Wildlife-11. Baiting through the use of zinc phosphide would be restricted to once per year during the summer at the entrance to burrows; use of zinc phosphide shall be confined to an area inside the entrance of burrows ( burrow baiting ) so as to minimize access from ground level. Following the completion of the baiting period of approximately 6-10 days, the burrow shall be destroyed expeditiously per Wildlife MM-6. These measures in the form of MM Wildlife-11, Pesticide Impact Reduction, would prevent contact of this bait with this species, and reduce potential impacts to a level of non-significance. With mitigation, the potential impacts to the San Francisco dusky-footed woodrat would be less than significant. EROSION CONTROL, BANK STABILIZATION, EMBANKMENT REPAIRS, ACCESS ROAD AND BOAT RAMP REPAIRS, AND TRASH AND DEBRIS REMOVAL Erosion control, bank stabilization, embankment repairs, and access road and boat ramp repairs activities could potentially impact San Francisco dusky-footed woodrats if they were to occur in or immediately adjacent (within 50 feet) to chaparral or woodland habitat where a woodrat individual or nest is found. MM Wildlife-12 would reduce the impacts to San Francisco dusky-footed woodrats due to these activities to a less than significant level. The mitigation requires assessment of woodrat habitat, avoidance where possible, and/or relocation to restored, enhanced, or created woodrat habitat. Trash and debris removal could potentially impact San Francisco dusky-footed woodrats. If a trash or debris pile at Almaden, Anderson, Calero Main, Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, or Uvas dams has been left overnight, it may become occupied by woodrats, and if it is left long enough it may become suitable nesting habitat for the San Francisco dusky-footed woodrat. Individual woodrats could be directly impacted during removal. Additionally, if trash or debris removal activities were June 2011 Page 3-103

156 Section 3.3 Wildlife CHAPTER 3 to occur in or near chaparral or woodland habitat, individual woodrats could be impacted either by indirect disturbances due to noise or direct harm, injured, or death by equipment. MM Wildlife-12 would reduce potential impacts to San Francisco dusky-footed woodrats due to trash and debris removal to a less than significant level. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures could potentially impact San Francisco dusky-footed woodrats if activities were to occur in or near chaparral or woodland habitat with woodrat nests. Individual woodrats could be indirectly impacted by disturbances due to noise and vibration if work were to occur immediately adjacent to an active nest. Weep hole cleaning could also potentially impact a woodrat taking refuge in the weep hole. MM Wildlife-12 would reduce the impacts to San Francisco dusky-footed woodrats due to maintenance of appurtenant structures to a less than significant level, by surveying prior to the activity, and avoiding the impact if the species is present. In addition, MM Wildlife-8 would require monitoring and avoidance for work in weep holes and expansion joints. INSPECTION, MONITORING, AND EXPLORATORY WORK Exploratory work could potentially impact San Francisco dusky-footed woodrats. If work were to occur within suitable chaparral or woodland habitat, ground disturbance during exploratory work could directly impact active San Francisco dusky-footed woodrat nests. Additionally, if exploratory work activities were to occur in or 54immediately adjacent to chaparral or woodland habitat, individuals could be impacted either by indirect disturbances due to noise or direct harm, injury, or death by equipment. MM Wildlife-12 would reduce the impacts to San Francisco dusky-footed woodrats due to exploratory work to a less than significant level Ringtail Suitable foraging habitat for the ringtail is present in the riparian and oak woodland habitats at eleven of the sites. Calero Auxiliary, Rinconada Treated Water Reservoir, and Vasona dams do not have suitable habitat since they are influenced by urbanization and/or do not support the appropriate woodland habitat. Ringtails nest in hollow trees or rock piles. Removal or destruction of ringtail dens would be considered a significant impact. SURFACES WORK VEGETATION MANAGEMENT Vegetation management within woodland habitat, particularly the initial removal of large, mature trees where ringtails may occur, could potentially result in June 2011 Page 3-104

157 Section 3.3 Wildlife CHAPTER 3 significant impacts. Acreages of woodland within the project area are shown in Table The loss of woodlands on the dams represents a very small portion of ringtail home ranges that are typically over 100 acres. Continuous woodlands exist adjacent to the dams that are identified as having potential for ringtail presence. If vegetation management activities occur within woodland habitats, mitigation measure MM Wildilfe-13 would be required to reduce the impacts on ringtails to less than significant. BURROWING RODENT CONTROL Burrowing rodent control activities could potentially impact ringtails. If ringtails are accidentally trapped in live traps, they could be adversely impacted. MM Wildlife-5 would be implemented to minimize effects to less than significant levels. This measure requires release of trapped non-target species and that the live traps are designed to avoid harm. This measure also requires that kill traps shall be buried in burrows so as to minimize possible harm to non-target species at ground level. Although the ringtail is primarily carnivorous, there is the possibility of foraging on grain. The dam faces are typically devoid of trees or shrubs that would provide habitat for the ringtail; however as a precaution the requirements of MM Wildlife-13 will limit placement of bait stations to 155 feet or more from ringtail nests. Since the ringtail is primarily carnivorous, secondary poisoning is a potential impact for anticoagulant bait such as chlorophacenone which can be absorbed into an animal s muscle tissue and organs. Implementation of BMP BI-7, Avoidance of Secondary Poisoning from Rodenticide Use, will require carcass surveys and removal of carcasses within 3 days of application. The application of zinc phosphide presents a low potential for secondary poisoning because it does not reach muscle tissue or may break down after it is eaten. To minimize this potential impact, where zinc phosphide, a faster acting bait, is applied, MM Wildlife-11 requires that carcass surveys begin the first day after application of bait. Implementation of these measures will reduce potential impacts to the ringtail to a less than significant level. EROSION CONTROL, BANK STABILIZATION, EMBANKMENT REPAIRS, ACCESS ROAD AND BOAT RAMP REPAIRS, AND TRASH AND DEBRIS REMOVAL Erosion control, bank stabilization, embankment repairs, and access road and boat ramp repairs activities could potentially impact ringtails if they were to occur in woodland habitats. Trash and debris removal could potentially impact ringtails. If a trash or debris pile at Almaden, Anderson, Calero Main, Calero (Fellows Dike) Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, or Uvas dams has been left unmanaged it may become occupied by ringtails. June 2011 Page 3-105

158 Section 3.3 Wildlife CHAPTER 3 MM Wildlife-13 would reduce the impacts to ringtails due to these activities to a less than significant level. This mitigation requires assessment of ringtail habitat, and avoidance. Trash and debris shall not be stockpiled overnight to prevent occupation by ringtails at dams where ringtails have been identified. MAINTENANCE OF DAM APPURTENANCES, AND EQUIPMENT Maintenance of appurtenant structures is not likely to affect ringtails since this activity does not include alteration of woodland habitats. It may be possible for ringtails to enter structures or equipment; in the event that ringtails are present when work is taking place, they could be impacted. MM Wildlife-13 would reduce the impacts to ringtails due to these activities to a less than significant level. The mitigation requires assessment of ringtail habitat, and avoidance. INSPECTION, MONITORING, AND EXPLORATORY WORK Exploratory work could potentially impact ringtails if work were to occur within woodland habitat. Individuals could be impacted either by indirect disturbances due to noise or direct harm, injury, or death by equipment. MM Wildlife-13 would reduce the impacts to ringtails due to exploratory work to a less than significant level Potential Impact to Interfere Substantially With the Movement of Any Native Resident or Migratory Fish or Wildlife Species or With Established Native Resident or Migratory Wildlife Corridors, or Impede the Use of Native Wildlife Nursery Sites The effects of DMP activities on special status wildlife are discussed above in Section Assessing the importance of an area as a movement corridor depends on differentiating between animals consistent use patterns. Animal movements can generally be divided into three major behavioral categories: Movements within a home range or territory Movements during migration Movements during dispersal The project would primarily result in temporary impacts to small areas of upland habitats in the vicinity of the dam faces. Many of these areas are already disturbed or manipulated. However, there are a number of species that could be migrating through the upland, riparian and aquatic habitats within the project boundaries of the various dam sites. DMP activities within the onsite riparian and aquatic habitat are expected to be minimal with a likely total for all dam sites collectively of approximately 2 acres of riparian proposed for removal. Therefore, any species currently moving through the various dam sites would continue to do so after the completion of the various DMP activities. The time spent performing the DMP activities is only a small portion of total time available for wildlife June 2011 Page 3-106

159 Section 3.3 Wildlife CHAPTER 3 access to the project area. Impacts of the DMP activities on the overall movement of native wildlife species would be less than significant. Except for Rinconada Treated Water Reservoir Dam, which is not sited on a stream, and Coyote Percolation Ponds Dam, where passage is provided by a fish ladder, the dams represent an upper barrier to fish migration; thus, DMP activities would not affect fish migration (dewatering is addressed below). For Coyote Percolation Ponds Dam, the District maintains a fish ladder bypassing the dam, which under a Streambed Alteration Agreement with DFG, is required to be operational at all times (SAA R3, September 2010). Thus impacts of DMP activities on fish passage, with the exception of dewatering, would be less than significant. The slight reduction to the prey base for predatory avian and mammalian species resulting from burrowing rodent control activities at the 14 dams, which total approximately 360 acres in size and of which only a portion would be impacted, would not be considered significant. Large predators, such as the gray fox, coyote, bobcat, and cougar have very large home ranges. Typically, a predator s home range is a few square kilometers to several hundred square kilometers and impacts to a very small percentage of habitats and their associated prey bases within these home ranges would not affect local predatory species. For example, the elimination of available prey base within a 20 acre area would affect 0.05 percent of a male cougar s home range (typically 38,400 acres), 0.50 percent of a bobcat or coyote s home range (typically 4,000 acres), and 3.00 percent of a gray fox s home range (typically 700 acres). Therefore, burrowing rodent control activities would not significantly impact the movement or predatory activities of locally occurring predators. Burrows may serve as nursery sites for California ground squirrels. Although no squirrels were seen during winter burrow removals (SCVWD 2010), young and adult squirrels are frequently seen on dams during summer. If the burrows do serve as nursery sites, the elimination of burrows would impede the use of a natural nursery. Burrows may also serve as sheltering or nursery sites for native, non-special status salamanders, toads, frogs, lizards, snakes, and rodent species other than ground squirrels. Before the wildlife agencies issue a take permit for CTS and CRLF, the burrows would be searched with a burrow camera prior to destruction, and native fauna would be relocated, in coordination with wildlife agency direction (MM Wildlife-6). After the wildlife agencies issue a take permit for CTS and CRLF, however, the burrows would be destroyed without prior searching, and fauna within the burrows would most likely harmed during the excavation and compaction process. Since the District would expeditiously remove burrows to avoid a larger occupation potential (included in MM Wildlife-6), loss of burrows as nursery sites would not constitute a significant impact upon populations of native fauna that could be using the burrows. There is a potential for weep hole and expansion joint maintenance to interfere with the movements of native wildlife. Amphibians, reptiles and small mammals are regularly found in weep holes and expansion joints that serve as cover sites/refugia, (i.e., those weep holes or expansion joints that are not occluded with soil and debris). These wildlife may be killed or injured during weep hole or expansion joint cleaning or repair of these structures. The potential for killing or injuring wildlife would be repeated whenever maintenance occurs (planned bi-annually), since weep holes and expansion joints will be available for re-occupation by wildlife between maintenance events. Populations of wildlife June 2011 Page 3-107

160 Section 3.3 Wildlife CHAPTER 3 species that regularly occupy weep holes and expansion joints are likely to decrease over time as individuals are removed from the populations during maintenance activities and localized extirpations of some species may result. In addition, application of herbicide to vegetation growing in weep holes, expansion joints or other locations has the potential to affect amphibians that could be seeking refuge there. Avoidance of adverse affects on wildlife in weep holes and expansion joints would be mitigated by MM Wildlife-8 which requires that weep holes and expansion joints be searched for wildlife by qualified biologist(s) on the day of maintenance to ensure that no wildlife will be harmed by the cleaning or repair. MM Wildlife-8 describes the procedure for biological surveys for weep holes and expansion joint maintenance to minimize killing or injuring wildlife that are found in the weep holes and to minimize potentially significant impacts to special status species that could occur in the weep holes. Application of MM Wildlife-4 to restrict the use of herbicides on the US EPAs injunction list would avoid impacts to these sensitive species. The injunction pesticides are listed in Appendix XI. Application of these mitigation measures would reduce the impacts associated with weep hole and expansion joint maintenance to a level of non-significance. There is a potential for rodent control activities to impact the movements of the western gray squirrel, a native squirrel to the project area and a game animal so designated by CDFG. Gray squirrels are not target rodents but could be impacted if they access the bait stations. The gray squirrel habitat requires the presence of trees and dense vegetation, which is a similar requirement for woodrat habitat. The dam faces are for the most part lacking trees and dense vegetation; however habitat is available near the dam faces on some dams. MM Wildlife-11 which establishes a 155-foot buffer between bait stations and gray squirrel nests from application of pesticides would reduce impacts to a level of less than significant. There is a potential for kill traps to harm non-target wildlife such as reptiles, amphibians and mammals, thereby affecting their movement in the project area. Kill traps would be either entirely buried within burrows so as to minimize the chances of harm to wildlife outside the burrow (MM Wildlife-5). With this mitigation measure in place potential impacts from kill traps would be reduced to a level of less than significant. There is a potential that dewatering of reservoirs could result in decreased streamflow which could hinder the movement of native fish or amphibians in streams below the dams. The effects of dewatering on movements of native fish would be mitigated by MM General-3 which requires the formulation of a dewatering plan which shall require ramping during dewatering to ensure that changes in flow are gradual, and to minimize their flushing effect on native fish or amphibians. To the extent feasible, ramping will provide a period of continuous flow over critical riffles and other barriers to allow upstream movement of aquatic species as the channels dry back. The plan shall require preparation of aquatic surveys of downstream reaches to identify fish and amphibians that may be stranded after the dewatering flows subside. Stranded fish and amphibians shall be relocated, in accordance with consultations with the appropriate resource agency. With these mitigation measures in place, potential effects of dewatering on the movement of native fish and amphibians would be less than significant. June 2011 Page 3-108

161 Section 3.3 Wildlife CHAPTER Potential to Conflict With Any Local Policies or Ordinances There are no local wildlife related policies or ordinances that pertain to this project Potential to Conflict With the Provisions of the Three Creeks Habitat Conservation Plan (HCP) or the Valley Habitat Conservation Plan (SCV HP) These two plans are described above under Regulatory Setting. To the extent of geographical overlap, the DMP is covered consistently in both documents. Care was taken to ensure that wildlife information presented in this EIR is consistent with occurrence and habitat requirements of wildlife species presented in the SCV HP. The wildlife mitigation measures for the DMP are aligned with mitigation measures in the SCV HP; and the SCV HP is intended to be used to obtain FWS permits for applicable DMP activities. In the public draft HP there is one area in which District seeks change in the final version. The HP currently states that burrows on the dam faces would be monitored using a burrow camera or similar device, prior to burrow destruction. The District will request that in light of the low likelihood for finding CTS or RLF in the burrows, and the high cost of this approach, that this bio-monitoring would no longer be required once the mitigation for CTS and RLF is in place. Accordingly, with this change in the HP, the DMP would not conflict with the provisions of the SCV HP. The Three Creeks HCP is currently in the preparation stage; great care has been taken to ensure that the covered activities of the DMP are described in a consistent manner in the Three Creeks HCP. Coordination between DMP and the Three Creeks HCP will ensure that DMP impacts and mitigation measures are consistent with the provisions of the Three Creeks HCP BMPS AND MITIGATION MEASURES Best Management Practices (BMPs) 13 In the event that these BMPs are revised in the future in the SCVWD Best Management Practices (BMP) Handbook, the District shall ensure that for each BMP listed below, equal or greater environmental protection is retained for the purposes of this EIR. BMP BI-2: Salvage Native Aquatic Vertebrates from Dewatered Channels. If native aquatic vertebrates are present when coffer dams, flow bypass structures, and silt barriers (temporary exclusionary fish screens) are to be installed, native aquatic vertebrates would be relocated at the discretion of a qualified biologist to ensure that native aquatic vertebrates are not significantly impacted. A site by site evaluation of species present or potentially present and habitat conditions would be made by a qualified biologist. When native aquatic vertebrate species relocation efforts are warranted, the operation would be based on the District s Fish Relocation Guidelines. 13 Source: SCVWD Best Management Practices (BMP) Handbook. August 31, June 2011 Page 3-109

162 Section 3.3 Wildlife CHAPTER 3 BMP BI-3: Salmonid Protection by In-Channel Work Timing. To avoid and minimize impacts to salmonids, routine use of vehicles and equipment in live salmonid streams will be avoided between January 1 and June 15. BMP BI-7: Avoid Secondary Poisoning from Rodenticide Use. Rodenticides shall only be used to protect District water storage and conveyance facilities, and mitigation sites from structural damage. The use of rodenticides shall be limited to locations that will not impact special status species or their habitat, and will minimize the potential impacts to non-target species. Rodenticide use shall include consideration of use of alternative non-lethal pest control methods. If rodenticide use is permitted, controls shall be established for before, during and after the rodenticide is used: 1. Prior to Use a Qualified District Biologist shall establish the following buffers, as they deem necessary, to protect listed (Threatened or Endangered) and sensitive species and/or habitat: a. At least 47 meters (approx. 155 feet) buffers from a San Francisco Dusky-Footed Woodrat nest; b. At least a ½ mile buffer zone around burrowing owl locations; and c. No use of lethal rodent control methods within the potential range of salt marsh harvest mouse (SMHM). 2. During Use the person applying the rodenticide will be fully certified for the rodenticide used. The bait station shall be designed and the rodenticide applied in a manner that restricts access from non-target species. The applicator will inspect the site on the fifth day after the rodenticide is made available, and then at least every third day while the rodenticide is available. The site inspection shall include ensuring that the rodenticide is being properly dispensed, monitoring the amount of rodenticide available, inspecting the site and vicinity for carcasses, and removing all animal carcasses. Carcass disposal will be performed in compliance with all applicable federal, state and local regulations, making the carcasses inaccessible to potential predators. 3. After use a Qualified District Biologist shall survey the area for unintended impacts such as secondary poisoning. Carcass surveys shall be conducted by the District s rodent control vendor to address the following: a. Location the survey shall include a range beyond the activity area, as deemed reasonably sufficient to determine the potential for secondary poisoning on listed and/or sensitive species, including raptors and other predators; b. Timing the survey shall be conducted when the rodenticide is most likely to be lethal, based on when it is applied, and repeated at appropriate intervals during the application period (e.g. for chlorophacinone, survey every June 2011 Page 3-110

163 Section 3.3 Wildlife CHAPTER 3 seven days while it is available; if a carcass is found, survey daily until no carcasses are found for three consecutive days); c. Response any dead non-target wildlife found in the vicinity of the treated area during the carcass surveys shall be turned over to California Department of Fish and Game s pesticide lab for analysis. BMP BI-8: Avoid Impacts to Nesting Migratory Birds. Nesting birds are protected by state and federal laws. The District shall protect nesting birds and their nests from abandonment, loss, damage or destruction. Nesting bird surveys shall be performed by a qualified individual (EMAP-30230) prior to any activity that could result in the abandonment, loss, damage or destruction of birds, bird nests, or nestling migratory birds. Inactive bird nests may be removed, with the exception of raptor nests. Birds, nests with eggs, or nests with hatchlings shall be left undisturbed. BMP BI-9: Use Exclusion Devices to Prevent Migratory Bird Nesting. Nesting exclusion devices may be installed to prevent potential establishment or occurrence of nests in areas where construction activities would occur. All nesting exclusion devices shall be maintained throughout the nesting season or until completion of work in an area makes the devices unnecessary. All exclusion devices shall be removed and disposed of when work in the area is complete. BMP HM-1: Comply With All Pesticide Application Restrictions. All pesticide use will be consistent with approved product specifications. Applications shall be made by, or under the direct supervision of, State Certified applicators under the direction of, or in a manner approved by the District s Pest Control Advisor (PCA). Refer to Q751D02, Control and Oversight of Pesticide Use. BMP HM-2: Use Appropriate Type(s) of Pest Control. Pesticide products are to be used only after an assessment has been made regarding environmental, economic, and public health aspects of each of the alternatives by the PCA. Refer to Q751D02, Control and Oversight of Pesticide Use. The following pesticide classes are used by the District: Pesticide Type of Use Herbicides To control algae, weeds and undesirable vegetation; To minimize fire hazards; To maintain flood conveyance of waterways; and To maintain compliance with State and Federal requirements. June 2011 Page 3-111

164 Section 3.3 Wildlife CHAPTER 3 Pesticide Type of Use Insecticides Use only in and around District buildings, or in the case of a serious pest outbreak, on landscape and re-vegetation facilities; Use only after all other methods, such as prevention or natural nontoxic control methods, have proven ineffective; and, Where required, the lowest toxicity will be used in accordance with the label and the details specified in Q751D02: Control and Oversight of Pesticide Use. Insecticides Use only in and around District buildings, or in the case of a serious pest outbreak, on landscape and re-vegetation facilities; Use only after all other methods, such as prevention or natural nontoxic control methods, have proven ineffective; and, Where required, the lowest toxicity will be used in accordance with the label and the details specified in Q751D02: Control and Oversight of Pesticide Use. Rodenticides To control burrowing rodents, including ground squirrels, moles and gophers, on District flood control levees and other facilities. Alternatives such as trapping and smoke bombs are used wherever practical prior to rodenticide use. BMP HM-8: Comply With Restrictions on Herbicide Use in Aquatic Areas. Consistent with provisions of Q751D02, Control and Oversight of Pesticide Use, only herbicides and surfactants registered for aquatic use will be applied within the banks of channels within 20 feet of any water present. Aquatic herbicide use shall be limited to July 1st through October 15th, except on Guadalupe River, where applications within 20 feet of the low flow channel are limited to July 1st to August 15th. If rain is forecast then application of aquatic herbicide will be rescheduled. BMP WQ-41: Prevent Stormwater Pollution. Suitable erosion control, sediment control, source control, treatment control, material management, and non-stormwater management BMPs shall be implemented consistent with the latest edition of the California Stormwater Quality Association Stormwater Best Management Practices Handbook, which is available at June 2011 Page 3-112

165 Section 3.3 Wildlife CHAPTER 3 Mitigation Measures MM Wildlife-1: Flow Bypass System. A flow bypass system shall be installed and implemented for any activity that would result in the interruption of flow downstream from the dam. The flow bypass system shall include: Pipes connecting the source of water to the stream; typically the source would be a reservoir, but it is possible that a pipeline could also serve as the source. Installation of fish screens to prevent fish from being sucked into the pumps. Implementation of mechanisms to control erosion and turbidity. Maintenance of flow rates downstream to keep the stream alive. Maintenance of suitable water temperature downstream. During the transition between the flow bypass system and normal reservoir levels, the release of water will be ramped up or down such that the flow rate to receiving waters is gradual and does not cause scouring of the channel bed. Location: All dams with inlet and outlet valves Schedule: Year round MM Wildlife-2: Aquatic Surveys and Temporary Exclusionary Screens 1. If it is determined that work must occur within a potential salmonid stream, avoidance and minimization measures set forth below shall be required year round for the steelhead trout and during the migration and spawning season for the Chinook salmon (October 1 through April 30 except in years with late storm events). The area where the work is proposed, as well as upstream below the toe of the dam and 50 feet downstream shall first be surveyed by a qualified biologist to ensure that no steelhead trout or Chinook salmon redds (nests), juveniles (fingerlings, parr, or pre-smolts), and/or adults are present within the stream channel. 2. Temporary exclusionary fish screens shall be erected downstream from the proposed work with a second layer of plastic construction fencing or other non-abrasive material on the side exposed to the fish. Screens shall be monitored for debris buildup and damage. Any debris observed accumulating along the screens shall be removed and any identified damage repaired. Screens shall not be placed near the Coyote Percolation Ponds during migration and spawning season unless the fish passage is not blocked, allowing schools to pass through the site unaffected. June 2011 Page 3-113

166 Section 3.3 Wildlife CHAPTER 3 3. If salmonids are found, the following measures shall be implemented. a. If juveniles or adults are observed, proposed work shall not occur until after unharmed individuals have moved out of the area on their own or have been relocated from the area by a qualified biologist. Relocation efforts would follow the District s, CDFG s, and/or NMFS most current relocation guidelines. b. If a redd is identified upstream below the foot of the dam or 50 feet downstream from the location of the proposed screen and/or stream disturbance during the migration and spawning season, work shall be postponed until all juveniles have emerged and been relocated. A redd within this buffer shall require that a quarter inch hardware cloth (wire mesh fencing) be staked around the redd in a circular fashion, enclosing the redd. This fencing would allow water to pass by the redd, but emerging juveniles would be restricted to a small area. Following the installation of the hardware cloth, a qualified biologist shall survey the redd weekly to determine when juveniles have begun to emerge. Once the first juvenile has been observed, surveys shall be conducted daily, early in the morning to minimize predation, until all juveniles have emerged. Emerging juveniles shall be relocated downstream from the screen. The hardware cloth shall remain intact until it has been determined that all juvenile have emerged. 4. If work is to occur in aquatic habitat where foothill yellow legged frogs, California red-legged frogs, western pond turtles or California tiger salamanders could be present, surveys shall be taken. If any of these species are found during the surveys, relocation shall be performed by a qualified biologist in coordination with the appropriate resource agencies. Temporary exclusionary screens shall be erected downstream from the proposed work. Screens shall be monitored for debris buildup and damage. Any debris observed accumulating along the screens shall be removed and any identified damage repaired. Location: Almaden, Anderson, Chesbro, Coyote Percolation Ponds, Guadalupe, Stevens Creek, and Uvas dams for salmonids and all dams except Rinconada Treated Water Reservoir Dam for the other species. Schedule: Year round for steelhead trout; migration and spawning season for Chinook salmon. Year round tor the foothill yellow legged frog, California red-legged frog, western pond turtle and California tiger salamander. MM Wildlife-3: Conduct Compensatory Mitigation for Take of California Tiger Salamander, California red-legged frog, Foothill yellow legged frog and Western Pond Turtle. The District shall provide the following compensatory habitat mitigation for unavoidable and permanent impacts to the California tiger salamander and California red-legged frog, foothill yellow legged frog and western pond turtle associated with DMP activities including rodent control, vegetation management, burrow elimination, exploratory work and maintenance of appurtenant facilities. Compensatory mitigation for specific affected areas shall only occur once during the maintenance program. That is, once habitat mitigation has been achieved for a specific maintenance area, no further compensatory mitigation is required for future maintenance of that area regardless of the type of maintenance activity, provided the previous habitat mitigation has been and continues to be successfully implemented. Impact data, such as the number of burrows June 2011 Page 3-114

167 Section 3.3 Wildlife CHAPTER 3 with special-status species present, and number of special status species harmed or translocated shall be included in an annual report and discussed with the appropriate regulatory agencies on an annual basis. The District shall mitigate for unavoidable permanent impacts to these special status species and habitat by protecting and providing for long-term management of suitable compensatory lands. The District shall provide compensatory mitigation by implementing one of the following options: a. Participate in an appropriate regional HCP, such as the proposed Santa Clara Valley HP or Three Creeks HCP, when and if approved and implemented; or b. Provide for compensatory mitigation by using existing USFWS and CDFG approved mitigation banks in appropriate ecological regions; or c. Provide for compensatory mitigation by protecting appropriate mitigation lands in perpetuity. For item (a) above, the covered activities will be clearly described in the approved habitat plan, and the District will make the appropriate contribution required to fully compensate for the impacts in accordance with the approved conditions and protocol. For items (b) and (c) in the above approach to providing compensatory mitigation, the District will be responsible for the preservation or creation of habitat that fully offsets the function and value of the habitat impacted. To this end, the District shall provide suitable habitat for impacted special status species that meets the following criteria: a. Replacement habitat for special-status species or special-status species habitat shall be determined in consultation with the appropriate regulatory agencies; b. The compensatory mitigation provided shall provide suitable replacement habitat for impacted special-status species or special species habitat; and c. Site(s) will not contain known hazardous materials sites or other conditions which would make them unsuitable for conservation for the species. The District will provide adequate funding for compensatory mitigation on an agreed-to schedule, following the discussion with the regulatory agencies, to ensure long-term protection and management of lands acquired or placed under conservation easement. Habitat monitoring shall track acres of habitat impacts, and enable the District to ensure that an equal or greater quantity and quality of mitigation will replace the impacted habitat. Data regarding the presence of California tiger salamander and California red-legged frog will be acquired in advance of and during DMP implementation and will be used, in coordination with the USFWS and CDFG, to determine if mitigation objectives have been achieved. June 2011 Page 3-115

168 Section 3.3 Wildlife CHAPTER 3 MM Wildlife-4: Injunction Pesticides Restriction. Pesticides on the US EPAs list of injunction chemicals 14 would not be used at any dam where California tiger salamander, California red-legged frog, or foothill yellow-legged frog could occur, or where steelhead or Chinook salmon could occur downstream of a dam, unless the pesticide has been evaluated, re-licensed and deemed not to be harmful to relevant listed species by the appropriate regulatory agency. Rodenticides would not be applied as scatter bait unless re-licensed for such purposes. No herbicides prohibited from use by the Court Stipulated Injunction to the US EPA, that are not otherwise excluded from the injunction, will be used in California red-legged frog critical habitat or in other US EPA-identified sections in Santa Clara County. Use of pesticides is currently not covered by federal HCP permits. All use of pesticides is subject to the County s current Integrated Pest Management Ordinance and District BMPs. Location: Anderson, Almaden, Calero (Auxiliary, Fellows Dike, and Main), Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, Uvas, and Vasona dams. Schedule: Year round. MM Wildlife-5: Trapping Impact Minimization and Avoidance Measures for Non-Target Species. California Tiger Salamander, California Red-legged Frog, Foothill Yellow-Legged Frog, and Western Pond Turtle. Traps would not be utilized during winter storm events to avoid the trapping of California tiger salamanders traveling to and from upland habitat and breeding ponds or California red-legged frogs, foothill yellow-legged frogs, or western pond turtles. In the unlikely event that one of these animals is trapped in a live trap during a dry trap night, the trap would be moved to the nearest suitable habitat for release (i.e., area with ample cover available or breeding pond if nearby) and the trap door would be propped open allowing the individual to escape untouched and unharmed. Live traps shall be stocked with fleece for warmth, a water supply, and a cover to provide shade for temperature moderation. If a trapped individual is harmed, injured, or dead, the USFWS and/or CDFG shall be contacted immediately for instructions on how to handle the individual. Kill traps shall be buried in burrows so as to minimize possible harm to non-target species at ground level. Location: Anderson, Almaden, Calero (Auxiliary, Fellows Dike, and Main), Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, Uvas, and Vasona dams. Schedule: Year round. Woodrat, ringtail and other non-target species. In the event that a San Francisco dusky-footed woodrat, ringtail or other non-target species is inadvertently trapped in a live trap, the trap would be moved immediately to the nearest habitat suitable for the species and the trap door would be propped open, allowing the individual to escape untouched 14 The term EPA s list of injunction pesticides refers to those pesticides named in the court settlement agreements of 2006 and 2010, as described above in section Regulatory Setting. June 2011 Page 3-116

169 Section 3.3 Wildlife CHAPTER 3 and unharmed. Traps would be stocked with fleece for warmth, a water supply, and a cover to provide shade for temperature moderation. Kill traps shall be buried in burrows so as to minimize possible harm to non-target species at ground level. Location: All dams. Schedule: Year round. MM Wildlife-6: Protected Species Avoidance During Burrow Removal. Until such time as when the appropriate wildlife agencies issue take permits for DMP impacts to the California tiger salamander and California red-legged frog, the burrow collapse protocol (Appendix IX) shall be followed for collapse of burrows in areas where the California tiger salamander or California red-legged frog could occur. The protocol includes identifying and mapping burrows, preparing burrows for excavation by flagging openings, scoping the burrow with a burrow camera, initiating the excavation and photo documenting it, procedures to follow if a special status amphibian species is found in the burrow, training, monitoring, etc. Deep burrows may require multiple inspections/excavations before they are cleared for re-filling and compaction; deep burrows marked for follow-up during salamander/frog breeding season will be monitored using advanced techniques to detect burrows that were vacated to then be immediately grouted. If the step-wise burrow inspection process cannot display the full extent of the burrow or a burrow extends deep into the dam face and additional excavation will compromise the structural integrity of the dam, then the burrow will be flagged for avoidance and data will be collected on the remaining burrows on the site to determine the likelihood of the presence of a protected species. The likelihood of protected species in not fully inspected burrows will be determined by collecting data on the presence of sensitive species elsewhere on the project site both in the burrows and on the dam face. If at least 80% of the burrows are fully inspected and less than 5% of the burrows contain sensitive species, then the not fully inspected burrows will be determined to have a low likelihood of containing sensitive species. If burrows that cannot be fully inspected are determined to have a low likelihood of protected species, and the SCVWD has an incidental take permit then the burrows will be destroyed by grouting or compacting. When burrowing rodent control is first initiated, a qualified biologist using a burrow camera will conduct scoping of the burrows immediately prior to burrow excavation, filling, and compaction. If wildlife species are encountered during scoping, the qualified biologist will relocate the species to an area within the same general proximity, and within the same watershed, where the habitat will not be disturbed by the covered activities. The qualified biologist will work with the appropriate wildlife agencies to determine if translocation is appropriate and if so, where an appropriate location is for the translocation. The opportunity for non-rodent occupation of burrows would be minimized by the District s commitment to expeditiously remove burrows. The District will monitor the dam faces regularly and expeditiously collapse or fill any new burrows that appear. Location: Anderson, Almaden, Calero (Auxiliary, Fellows Dike, and Main), Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, Uvas, and Vasona dams. June 2011 Page 3-117

170 Section 3.3 Wildlife CHAPTER 3 Schedule: Year round. MM Wildlife-7: Avoidance and Impact Minimization Measures for Impacts to Individual California Tiger Salamanders, California Red-Legged Frogs, Foothill Yellow-Legged Frogs or Western Pond Turtles CALIFORNIA TIGER SALAMANDERS, CALIFORNIA RED-LEGGED FROGS, FOOTHILL YELLOW-LEGGED FROG Prior to or during any ground disturbance in areas where California tiger salamanders, California red-legged frogs, or foothill yellow-legged frogs could be located, the following measures shall be implemented to ensure individuals are not harmed as a result of DMP activities: 1. Monitoring and Initiation of DMP Activities a. Prior to initiating dam maintenance, the District will define and mark the boundary of the dam maintenance and monitor to ensure no activities take place outside of this boundary; b. If any of these species are found in the surveys the District shall either wait for them to move away from the impact area or a qualified biologist will remove them from the area and place them in appropriate habitat outside of the project boundary in accordance with the guidelines provided by the USFWS and/or CDFG; 2. The maintenance crew shall be trained (e.g., tailgate session prior to construction initiation) by a qualified biologist to ensure that they are not only aware of the protective measures they are to employ, but also understand the purpose of such measures. 3. A qualified biologist shall survey the site prior to ground disturbance activities in areas supporting suitable upland and/or breeding habitat to ensure individuals are not harmed. In the event that a special status species is observed within the disturbance footprint, the qualified biologist will move individuals to a predetermined offsite location, in accordance with the guidelines provided by the U.S. Fish and Wildlife Service and CDFG. If the pond below Calero Auxiliary Dam is in the area that could be directly disturbed, any larvae observed within the Calero Auxiliary Dam pond will be left undisturbed until fully developed into adults that were able to survive outside of the pond. For locations and at times when these species could be present, trash and debris will not be piled for more than one day. 4. Grazing shall be limited to the dry season when amphibians are not normally present on surfaces in upland areas. June 2011 Page 3-118

171 Section 3.3 Wildlife CHAPTER 3 WESTERN POND TURTLES Prior to any ground disturbance in areas where western pond turtles could occur, the following measures shall be required to ensure individuals are not harmed as a result of DMP activities: 1. If work is to occur within 60 feet of suitable riparian or aquatic habitat or directly impact suitable aquatic habitat where it has been determined that western pond turtles could be present, a qualified biologist shall conduct a pre-disturbance survey within 48 hours of activity initiation. 2. If individuals are observed within the disturbance area, a qualified biologist shall move individuals out of harm s way prior to disturbance. If a nest with eggs is found, the activity shall avoid disturbance of the nest, or wait until such time as the young turtles have hatched and moved off site. The nest shall be relocated only if permission from the appropriate wildlife agency is obtained, and agency conditions are followed. 3. If sedimentation or any other indirect impacts could potentially occur to suitable turtle habitat outside of the disturbance footprint, orange construction fencing shall be placed around the areas to be protected to ensure that DMP activities do not result in indirect impact. 4. The maintenance crew shall be trained (e.g., tailgate session prior to construction initiation) by a qualified biologist to ensure that they are not only aware of the protective measures they are to employ, but also understand the purpose of such measures. Location: Anderson, Almaden, Calero (Auxiliary, Fellows Dike, and Main), Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, Uvas, and Vasona dams. Schedule: Year round. MM Wildlife-8: Wildlife Avoidance During Weephole/Expansion Joint Cleaning and Repair. Weep holes (to the extent of the work activity, including the cavity behind the weep hole if it is to be filled) and expansion joints shall be monitored (using sunlight reflected from a mirror, a flashlight, or a remote camera or similar device that can provide visibility for the entire weep hole or joint crevice) by a qualified biologist on the day of cleaning or repair to ensure that no wildlife will be harmed by the cleaning activity or repair (e.g. filling of cavities behind weep holes). The District shall temporarily mark holes that either: (1) have an animal present, or (2) the entire insides of the hole cannot be seen and therefore it cannot be confirmed that no wildlife are present. The marked holes shall not be cleaned or repaired at that time. If a weep hole has soil and vegetation on the outside and frogs or other animals on the inside, the District shall skip cleaning or repairing the hole itself, and scrape off the soil and vegetation from the outside by hand without using power tools and without pushing material to the inside of the hole. June 2011 Page 3-119

172 Section 3.3 Wildlife CHAPTER 3 The District may choose to develop a screen to preclude wildlife from entering weep holes. If the screen is determined to successfully prevent wildlife from entering the weep holes, then the monitoring would no longer be necessary for those screened holes. Location: Anderson, Almaden, Calero (Auxiliary, Fellows Dike, and Main), Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, Uvas, and Vasona dams. Schedule: Year round. MM Wildlife-9: Horned Lizard Avoidance. Pre-activity surveys shall be conducted by a qualified biologist for California horned lizard prior to any work involving excavation, livestock grazing, or off-road access with heavy vehicles. If individuals are found, they shall be avoided or relocated by a qualified biologist prior to performing the work. Location: All locations. Schedule: Year round. MM Wildlife-10: Disturbance Free Buffer for Avoidance of Active Migratory Bird Nests. A disturbance free buffer shall be established if an active migratory bird nest is identified during the migratory bird survey. Raptors shall require a 250-foot buffer whereas other migratory birds, such as passerines, shall require a 50-foot buffer. DMP activities can proceed within the buffer area after the young have successfully fledged following the nesting season, as determined by a qualified biologist. Location: All sites. Schedule: During the nesting season, generally February 1 through August 31. MM Wildlife-11: Pesticide Impact Reduction. Bait stations, when used, shall be of a modified T-tube design, with maximum 3-inch entrances, so as to reduce access by non-target species; stations will be located at least 155 feet from woodrat, ringtail or gray squirrel nests; stations can be closer, provided that they are capped nightly so that woodrats are not exposed to the bait; if the stations are capped nightly, the timing of capping shall be determined by a qualified biologist. Herbicides will not be sprayed within 155 feet of woodrat nests. The cut stump method of herbicide application (without a spraying mechanism) will not be used within 10 feet of woodrat nests. Application of zinc phosphide shall be limited to once per year during the summer after grasses have died, and following a successful pre-baiting period. Use of zinc phosphide shall be confined to an area inside the entrance of burrows ( burrow baiting ) so as to minimize access from ground level. Carcass surveys shall be performed daily beginning the first day after application. Following the completion of June 2011 Page 3-120

173 Section 3.3 Wildlife CHAPTER 3 the baiting period of approximately 6-10 days, the burrow shall be destroyed expeditiously per Wildlife MM-6. Location: Anderson, Almaden, Calero (Auxiliary, Fellows Dike, and Main), Chesbro, Coyote, Coyote Percolation Ponds, Guadalupe, Lenihan, Stevens Creek, Uvas, and Vasona dams. Schedule: Year round. MM Wildlife-12: San Francisco Dusky-Footed Woodrats, Impact Avoidance and Compensation Avoidance: Prior to conducting activities within 155 feet of woodrat nests, a qualified biologist shall determine how much habitat should remain immediately adjacent to woodrat nest(s) to support the population on, or adjacent to, the project site. Herbicide applications shall not be sprayed within 155 feet of woodrat nests. Herbicide applications through the use of the cut stump method shall not be applied within 10 feet of woodrat nests. The cut stump method involves the cutting of a tree or shrub to a desired height and carefully applying a pre-approved herbicide to the cut area using a wick, absorbent wiper, or paint brush, and does not include the use of a spraying device. 2. Pre-activity surveys: If ground disturbing or weephole maintenance activities must occur within 155 feet of woodrat nests, a qualified wildlife biologist shall conduct a pre-activity survey to determine if woodrats are present. Surveys shall not be conducted more than 3 days before the start of the activity (or other disturbance associated with maintenance). Individual woodrats shall be avoided by allowing the animal to move out of harm s way on its own, or to remain where it is (if it is in a weep hole, for example) by avoiding working in that area (or avoiding cleaning that weep hole). At dams where woodrats have been identified, if trash and debris removal includes the stockpiling and crushing of woody debris, it shall not be stockpiled (either pre-crushed or crushed) overnight. All woody debris shall be hauled off the site and disposed the same day. If a qualified wildlife biologist determines that observed woodrat nests are uninhabited, no other steps are required. If woodrat nests are found to be occupied and cannot be avoided, the following actions shall be taken. a. Relocation to restored, offsite, enhanced, or created or conserved woodrat habitat: If project activities will impact active woodrat nests, then additional woodrat habitat shall be enhanced, restored, or created in order to compensate for woodrat habitat losses. In compensation areas, existing habitats and woodrats will be described in a woodrat mitigation plan and mapped to determine where enhancement or restoration can be used for new woodrat habitat. Restoration or enhancement sites shall be located outside the project area, if appropriate onsite locations cannot be found. At restoration or enhancement sites where structure, cover, or canopy for shade can be enhanced or restored, logs and stick resources 15 Taken in part from Recommendations for Mitigation Measures for the San Francisco Dusky-Footed Woodrat by Dave Johnston, PhD. DRAFT, Prepared for SCVWD, March 5, June 2011 Page 3-121

174 Section 3.3 Wildlife CHAPTER 3 (preferably collected from project impact sites), shall be moved to these specified locations; efforts will be made to avoid import of any organic material to the enhancement site. Each log pile shall consist of four-foot long, cm wide logs, stacked in a pyramid of nine logs with spaces. Fifty percent more log piles should be placed than the number of woodrat nest resources moved. Each log stack will be positioned in areas that will provide ample food and cover as an existing condition or as the restoration plantings mature. Additional plantings of food or cover will be used in areas that otherwise do not provide these critical resources. For example, elderberry (Sambucus mexicanus) and native blackberry (Rubus ursinus) can be used for both cover and food plants in areas that have overstory shade and structure but inadequate food resources. After the mitigation plan for impacts to woodrats has been approved by the CDFG, woodrat nest resources can be moved after dark to minimize predation. Prior to moving the woodrat nest materials, all understory vegetation shall be cleared within the area immediately surrounding the nests to be impacted but the nest itself should not be removed at this stage. Then, each active nest shall be disturbed by a qualified wildlife biologist) to the degree that all woodrats leave the nest and seek refuge off the site or impact area and into adjacent cover. The nest sticks shall be removed from the site and piled at the base of a nearby hardwood tree (preferably an oak or California bay with refuge sites among the tree roots) or on and adjacent log pile designed to provide structure for woodrat nests. The spacing distance between the newly placed piles of sticks shall not be fewer than 100 feet from each other, unless a qualified biologist has determined that a specific habitat can support higher densities of nests. Loss of woodland habitat shall be compensated at a ratio of 3:1, based on canopy area, and shall be accomplished either by purchase and protection in perpetuity, or creation. In any case the compensation shall replace functions lost from woodlands that are removed. If woodlands are created, a restoration plan shall be prepared and coordinated with the appropriate wildlife agencies before implementation. b. Monitoring woodrat populations: Monitoring restored or replaced woodrat populations shall occur over a 5-year period. Monitoring methods shall include the following: (1) Woodrat nests shall be surveyed during the breeding season once per year for year 1, year 3, and year 5; (2) Nest locations shall be plotted on a vegetation map; (3) Information regarding, height, width at base, species of canopy type, distance to nearest nest, species composition of nest sticks, species composition of the support structures (e.g., coast live oak log), the number of support pieces, the size of the largest support and the average size of the support pieces, shall be recorded; (4) Any observations or evidence that house cats are free-ranging shall be recorded; and (5) The data shall be provided to a designated representative for the CDFG on years 1, 3, and 5, as stated above, or as otherwise specified by the CDFG. The final success criterion for mitigation measures shall be met when the number June 2011 Page 3-122

175 Section 3.3 Wildlife CHAPTER 3 of active nests within the project site is equal to or greater than the number of active nests before impacts. If the final success criterion is not met within the 5-year monitoring period, an analysis of the cause of mitigation failure shall be made and remedial actions to correct the problem shall be required. The specific remedial action will depend on the cause of failure. Potential remedial actions include the replanting of foraging and cover plants for the San Francisco dusky-footed woodrats. If remedial actions are needed, a technical memo fully describing the proposed actions will be drafted and submitted to the CDFG for approval prior to implementing work. If remedial actions are implemented, the monitoring period will be extended for a minimum of 2 years and alternative mitigation site planning will begin if it becomes apparent that the long-term success criteria for the sites will not be achieved. The District shall be responsible for funding the planning, implementation and monitoring of any remedial measures required by CDFG to meet the success criteria of the mitigation. c. As an alternative to the restoration and monitoring measures set forth in paragraphs a) and b), above, loss of woodland habitat shall be mitigated through an approved Habitat Conservation Plan or Natural Community Conservation Plan. Where the District has complied with an applicable HCP or NCCP, no additional compensatory mitigation or monitoring shall be required. Location: All dams where the woodrat is found. Schedule: Year round. MM Wildlife-13: Ringtail Impact Avoidance, Habitat Mitigation. 1. Avoidance: Prior to conducting activities within 155 feet of ringtail nests, a qualified biologist shall determine how much habitat should remain immediately adjacent to ringtail nest(s) to support the population on, or adjacent to, the project site. Herbicide applications shall not be sprayed within 155 feet of ringtail nests. Herbicide applications through the use of the cut stump method shall not be applied within 10 feet of ringtail nests. Bait stations shall not be placed within 155 feet of ringtail nests. 2. Pre-activity surveys: If ground disturbing activities must occur within 155 feet of ringtail nests, a qualified wildlife biologist shall conduct a pre-activity survey to determine if ringtails are present. Surveys shall not be conducted more than 3 days before the start of the activity (or other disturbance associated with maintenance). Individual ringtails shall be avoided by allowing the animal to move out of harm s way on its own, or to remain where it is by avoiding working in that area. At dams where ringtails have been identified, if trash and debris removal includes the stockpiling and crushing of woody debris, it shall not be stockpiled (either pre-crushed or crushed) overnight. All woody debris shall be hauled off the site and disposed the same day. If a qualified wildlife biologist determines that observed ringtail nests are uninhabited, no other steps are June 2011 Page 3-123

176 Section 3.3 Wildlife CHAPTER 3 required. If ringtail nests are found to be occupied, impacts shall be avoided due to the fully protected status of the ringtail. 3. Habitat Mitigation: Loss of woodland habitat occupied by the ringtail shall be compensated at a ratio of 3:1, based on canopy area, and shall be accomplished either by purchase and protection in perpetuity, or creation. This mitigation should overlap, if possible, with mitigation habitat for the dusky footed woodrat, in Wildlife MM-12, above. The compensation mitigation shall replace functions lost from woodlands that are removed. If woodlands are created, a restoration plan shall be prepared and coordinated with the appropriate wildlife agencies before implementation. Location: All dams where the ringtail is found. Schedule: Year round. MITIGATION MEASURES FOR DEWATERING IMPACTS The District shall implement the following additional measures to mitigate impacts resulting from dewatering. Mitigation Measure General 1: Before any reservoir dewatering takes place, the District shall conduct a project level CEQA review of the reservoir dewatering. Mitigation Measure General 2: Before any reservoir dewatering takes place, the District shall consult with NMFS and any other applicable resource agency and obtain all necessary permits. Mitigation Measure General 3: Before any reservoir dewatering takes place, the District shall develop a reservoir specific dewatering plan. Each dewatering plan shall include the following mitigation components: 1. To minimize the effect of impact 1 (effects of high flows needed to drain the reservoirs) the plan shall include provisions for ramping so that changes in flow are gradual, and minimize their flushing effect on aquatic organisms. To the extent feasible, ramping shall be designed so that flows will not exceed winter base flows. Safe dewatering rates with respect to landslide prevention shall also be analyzed, determined and included. As dewatering ends, and low flows begin, to the extent feasible ramping will provide a period of continuous flow over critical riffles and other barriers to allow upstream movement of covered aquatic species as the channels dry back. The plan shall require preparation of aquatic surveys of downstream reaches to identify fish and amphibians that may be stranded after the dewatering flows subside. Stranded fish and amphibians will be relocated, in accordance with consultations with the appropriate resource agency. 2. To minimize the effect of impact 2 (low flows following reservoir dewatering), the plan shall include provisions for supplemental water sources to maintain quantity and quality of downstream flow to the extent feasible. The supplemental water sources shall be designed to supply water to the affected June 2011 Page 3-124

177 Section 3.3 Wildlife CHAPTER 3 streams to protect populations of rearing steelhead, California red-legged frogs, and foothill yellow legged frogs in the reaches below the District's dams during periods of dam dewatering for maintenance. To convey supplemental water sources, to the extent feasible, the plan shall utilize existing pipelines or upstream facilities to supply water downstream of the dam maintenance work (e.g. Anderson and Calero) or include building infrastructure to supply water at the base of the dam during dewatering events (e.g. Stevens Creek dam, where there are currently no existing facilities to supply water at the base of the dam). If supplemental flows cannot maintain the quantity and quality of water that would otherwise be available, additional provisions for fish rescue and feeding programs to support fish metabolism shall be included. 3. To minimize the effect of impact 3 (allowing non-native fish and amphibians to enter the streams from the reservoirs), the plan shall include the following provisions: a. In advance of dewatering of a reservoir, the District shall employ screens or other devices at the dam outlet to prevent exotic species in the reservoir from escaping to the downstream channel. b. Native fish or amphibians that are collected during dewatering shall be relocated in accordance with consultations with the appropriate resource agency. c. In any stream where reservoir dewatering effects on summer flow are not fully offset by supplemental water system flows, the District will maximize channel carrying capacity for native species by conducting exotic species removal during dewatering in the stream reaches with supplemental flows. Trapping and removal of bull frogs and other nuisance species during reservoir dewatering shall be in accordance with consultations with the appropriate resource agency RESIDUAL IMPACTS AFTER MITIGATION Impacts, except for those associated with reservoir dewatering, would be less than significant after application of the listed BMPs and mitigation measures. It is not known if the proposed programmatic measures and/or future measures would reduce all impacts of dewatering to less than significant. Accordingly, for purposes of this programmatic analysis, dewatering has potentially significant and unavoidable impacts on special status wildlife. June 2011 Page 3-125

178 Section 3.4 Hydrology and Water Quality CHAPTER HYDROLOGY AND WATER QUALITY ENVIRONMENTAL SETTING Overview This section describes regional water resources. The 14 dams included in the DMP are located throughout Santa Clara County within eight sub-watersheds as shown in Figure By their very nature, dams are hydrologic features serving to impound water for storage and other uses that would otherwise flow downstream or downslope. The hydrologic, drainage and water quality assessments of the DMP contained in this section are based upon prior hydrologic analysis in the APE, site observations, and the activities described in the DMP. General information on soils in the area of the project site was obtained from the U.S. Department of Agriculture (USDA) Soil Conservation Service (presently, Natural Resources Conservation Service, or NRCS), Soils of Santa Clara County (Helseth 1968), and Soil Survey of Eastern Santa Clara Area (Lindsey 1978). General groundwater information was drawn from the District Groundwater Management Plan (Reymers and Hemmeter 2001) and the 2003 update to the Department of Water Resources (DWR) Groundwater Bulletin 118. Wetland delineation assessments were prepared for this PEIR by LOA and are presented in Section 3.2 Vegetation and Habitat. Data regarding water quality conditions and dam operations were provided by the District Groundwater and Surface Water REGIONAL OVERVIEW The occurrence and movement of groundwater and surface water in the project area is dictated by regional climate and hydrologic characteristics but, to some degree, is managed by District activities. The northern two thirds of the District are located within the Santa Clara Basin, which is comprised of a number of major watersheds, all of which drain north to the San Francisco Bay. The southern portion of the District is located in the Uvas/Llagas watershed, which drains south to the Pajaro River and Monterey Bay. The District is underlain by three major, interconnected groundwater sub-basins: Santa Clara Valley, Coyote, and Llagas. The District is responsible for managing water resources in Santa Clara County. Runoff from primarily rural areas in the foothills is collected in the District s reservoirs for storage and/or blending with imported water before being conveyed to groundwater recharge facilities or drinking water treatment plants. The District sells both groundwater and treated surface water to retail agencies that serve the communities within the County via their own distribution systems. CLIMATE The project area has a Mediterranean climate, with almost all precipitation falling between the months of November and April. Annual average rainfall amounts vary significantly due to topography. Higher elevations in the Santa Cruz Mountains can June 2011 Page 3-126

179 Section 3.4 Hydrology and Water Quality CHAPTER 3 receive 40 to 60 inches per year, while the Valley floor in the vicinity of downtown San Jose receives on average about 15 inches annually. Average rainfall conditions for the area are highly variable. Periods of abundant winter precipitation and prolonged periods of drought are both frequent in the historical record. For example, the average annual rainfall for San Jose is approximately 15 inches per year but annual rainfall over the last 100 years or so has ranged from 6 to over 30 inches (Santa Clara County 1994). GROUNDWATER Aquifers (water bearing strata) within the Santa Clara Valley, Coyote, and Llagas groundwater basins supply nearly half of the District s total water supply. Groundwater replenishment occurs both naturally and through District efforts to augment natural processes. Percolation facilities, usually located near the basins perimeters, are used to increase the recharge of groundwater basins and to compensate for the amount of water withdrawn. In the low foothills at the edge of the sub-basin, the geologic materials that compose the aquifers are exposed at the ground surface. These zones are collectively known as the forebay of the aquifer. In these exposed areas, rainfall, streamflow, and other surface water are able to infiltrate and to seep into the aquifer (Iwamura 1995). The District actively promotes recharge to the aquifer using local and imported water applied to about 390 acres of off-stream percolation ponds located throughout the County. Seasonal dams, such as the Coyote Percolation Ponds Dam, are also used to encourage in-stream recharge (Reymers and Hemmeter 2001). Release of imported water to streams augments streamflow conditions that are used by fish and wildlife. Historically, many of the streams have gone dry during the summer. The release of stored water from reservoirs serves to maintain flows at times when the streams would otherwise be dry. In addition to helping to maintain groundwater supplies, recharge ameliorates problems related to land subsidence. Subsidence is a broad sagging of the land surface over many miles as a result of decreased water pressure in the underlying aquifers. It is a phenomenon that has occurred extensively in the northern Santa Clara sub-basin during the twentieth century due to over pumping of the aquifer (Ingebritsen and Jones 1999). District recharge operations (along with availability of imported water in lieu of ground-water pumping) have helped raise water levels and curb land subsidence (Reymers and Hemmeter 2001). June 2011 Page 3-127

180 Figure 3.4-1: Dam Locations by Watershed June 2011 Page 3-128

181 Section 3.4 Hydrology and Water Quality CHAPTER 3 Groundwater generally exists at depths below the streambeds, except in the lower courses of a few of the larger streams, notably Coyote Creek north of downtown San Jose. Because it is sustained by groundwater, Coyote Creek is perennial. Most of the other creeks in the basin are naturally dry during the summer (Clark 1924). In an effort to recharge the groundwater basins, water is released from reservoirs and/or the raw water distribution system by the District during summer months into many creeks that would otherwise be dry under natural conditions. Most recharge takes place within the transition zone from the foothills to the valley floor where the upper reaches of the creek beds tend to be composed of much coarser sediment than the lower reaches. Perhaps more significantly, underlying sediments in the lower reaches are often composed of nearly-impervious lakebed (South County) or tidal (adjoining the Bay) deposits, precluding deep infiltration. The District takes a balanced approach to managing water releases for recharge, recognizing aquatic habitat values. When there is adequate water stored in the reservoirs, flows sustained by releases may reach the Bay Major Watersheds and Surface Waters OVERVIEW OF WATERSHEDS Most watersheds in the District are similar in geographic structure, with headwaters in relatively rural, undeveloped mountainous areas (Santa Cruz Mountains or Diablo Range) and outlets on the margins of San Francisco Bay or the Gilroy-Hollister Plain where residential and commercial development can be quite dense. Near San Francisco Bay, many streams are tidally influenced and hold varying degrees of brackish and saline water. The southern portion of the District is somewhat more rural overall. It drains southward to the Pajaro River, which discharges to Monterey Bay. In rural environments, particularly those with low relief, many creeks have been rerouted in an effort to drain and accommodate adjacent farmland. In urban areas, channelization and culverts are common features that were installed to reduce flooding in adjacent uplands. Many of these historical improvements removed the hydrologic connection between the channel and the floodplain resulting in impacts such as higher peak flow velocities, erosion problems, reduced riparian habitat values, and flooding in upstream or downstream reaches. Several culverts and channelized sections are now being removed and restored as part of District programs such as the Clean, Safe Creeks and Natural Flood Protection Plan, and the SMP. The SCVWD s dams are under the regulatory jurisdiction of the DSOD. The reservoirs provide some incidental flood protection 16 by containing runoff early in the rainfall season, serve recreational needs, and benefit the environment by storing water to maintain flow in the creeks. The management of stored water is adjusted as seasonal conditions change. The magnitude, duration and frequency of spills and releases varies between dams and across seasons, depending upon the nature of the rainfall year, the amount of water already impounded at each site and the need to release water downstream to meet recharge, treatment, and/or habitat needs at other locations or facilities. Most stored water is released in the spring and summer 16 Chesbro Reservoir was designed for both flood protection and water supply; all other District reservoirs were primarily constructed for water supply purposes. June 2011 Page 3-129

182 Section 3.4 Hydrology and Water Quality CHAPTER 3 after the rainfall season and allowed to percolate into the underground aquifers, or it is sent to district treatment plants. Reservoirs typically fall to their lowest levels in the late fall, but rarely are empty. During the winter, in addition to overflow from the reservoirs when their capacity is exceeded, some water is released for percolation. When reservoirs fill early in the winter season, water may be released to provide more storage capacity for later-season storm runoff and to improve stream habitat. During a dry winter, releases are usually reduced to conserve the amount of stored water and to ensure habitat protection throughout the year. COYOTE CREEK WATERSHED The Coyote Creek watershed covers approximately 350 square miles and is the largest watershed in Santa Clara County. Its headwaters, which flow generally south and west, are located in the non-urbanized, west-facing slopes of the Diablo Range. Approximately half of the watershed area is located above Coyote and Anderson Reservoirs. Flow below Anderson Reservoir is regulated by District operations activities, which are governed by a number of criteria including District water needs, flooding hazards, and recreation and ecological concerns. Stream flow is impounded in-stream at the Coyote Percolation Ponds Dam for groundwater recharge. Without augmentation by the District, the channel reach immediately downstream of the percolation ponds would be dry during most summer and early fall months. Lower reaches of Coyote Creek are fed by groundwater throughout the year and seasonal flows from Lower Silver Creek, Upper Penitencia Creek, and Lower Penitencia Creek. Cherry Flat Reservoir is located on Upper Penitencia Creek, operated by the City of San Jose Water and is not considered in this program. Residential and light industrial development comprise the major land uses in the lower reaches of the Coyote Creek watershed and these uses are rapidly expanding in the area between Highway 85 and Morgan Hill. Coyote Dam is located within the foothills of the Diablo Range in the Coyote Creek Watershed approximately 6 miles east of downtown Morgan Hill and 6.3 miles upstream of Anderson Dam. It has a drainage area of 119 square miles, approximately 70 percent of the watershed drainage to Anderson Dam. The reservoir extends 4.8 miles and has a capacity of 23,244 acre-feet and surface area of 648 acres at full pool although it is typically operated at a much lower level of impoundment per operational storage restrictions. Anderson Dam is located at the base of the Diablo Range in the Coyote Creek Watershed approximately 2.5 miles northeast of downtown Morgan Hill. It has a drainage area of square miles, including the drainage area for Coyote Dam. The reservoir has a total length (at full capacity) of about 7.8 miles, extending north into the San Felipe Creek basin and south into the Coyote Creek basin. Anderson Lake has a storage capacity of 90,373 acre-feet and a maximum surface area of 1,271 acres making it the largest lake within Santa Clara County. Water stored in Anderson Reservoir is used for recharge in the stream bed and can be used as a water supply for District water treatment plants. June 2011 Page 3-130

183 Section 3.4 Hydrology and Water Quality CHAPTER 3 Coyote Percolation Ponds Dam is located on the floor of the Santa Clara Valley in the Coyote Creek Watershed approximately 10 miles northwest of the city of Morgan Hill, 10 miles southeast of the City San Jose, and 9.5 miles downstream of Anderson Dam. It has a drainage area of 220 square miles. The reservoir extends 0.8 miles and has an original design capacity of approximately 402 acre-feet and surface area of approximately 37 acres when filled. Water is diverted/re-diverted here for groundwater recharge within the basin, for controlled release to Coyote Creek downstream for groundwater recharge, and for use in an adjacent wetland mitigation site. GUADALUPE RIVER WATERSHED The Guadalupe River watershed covers approximately 170 square miles. The river s headwaters are located in the eastern Santa Cruz Mountains and it drains to the San Francisco Bay through Alviso Slough. The Guadalupe River begins at the confluence of Guadalupe Creek and Alamitos Creek (to which Calero Creek is tributary); downstream from this point the watershed is heavily urbanized. Important tributaries include Ross Creek, Canoas Creek and Los Gatos Creek. Since 1866, the Guadalupe River and its tributaries have been the focus of several flood control modification projects. Approximately 21 percent of the channels in the watershed have been converted to concrete or rock-lined channels, 38 percent are manmade earthen channels and only 40 percent have been left unmodified (SCBWMI 2000). The high percentage of impervious surface in the watershed contributes to flashy flows 17, which have historically resulted in flooding of the lower Guadalupe River. Flows are partially regulated by the District which operates five major reservoirs in the watershed: Almaden Reservoir on Alamitos Creek, Guadalupe Reservoir on Guadalupe Creek, Calero Reservoir on Calero Creek, and Lexington Reservoir and Vasona Reservoir on Los Gatos Creek. Williams Reservoir, Lake Elsman, Kittridge, Cozzens and Lake Ranch (aka McKenzie) reservoirs are also within the Los Gatos Creek sub-watershed but are operated by San Jose Water Company and are not considered in the DMP. The District augments dry season flows in the Guadalupe River and its tributaries for the purposes of ground-water recharge. Flows are also diverted to several ground-water percolation ponds along Guadalupe Creek, the Guadalupe River and Los Gatos Creek. Historic mercury mining in the upper watershed has left a legacy of mercury contamination. Almaden Dam is located on the eastern side of the Santa Cruz Mountains in the Guadalupe Watershed, approximately 11 miles southeast of the City of Campbell. Almaden Reservoir has a total length of 1.1 miles, covers 57 acres, and has a capacity of 1,586 acre-feet at full pool. Alamitos Creek and Larabee Gulch feed Almaden Reservoir. Water stored in Almaden Reservoir can be diverted to Calero Reservoir via the Almaden-Calero Canal. Calero Reservoir is located at the base of the Santa Cruz Mountain foothills in the Calero Creek Watershed approximately 8 miles northwest of downtown Morgan Hill. The main and auxiliary dams serve to impound runoff from the 6.9 square miles drainage area. The majority of impounded water at Calero is supply that has been diverted at Almaden Reservoir and water that is introduced via a turnout from the 17 Flows and water levels in flashy systems are highly responsive to storm intensities. June 2011 Page 3-131

184 Section 3.4 Hydrology and Water Quality CHAPTER 3 Cross-Valley pipeline, tied to the imported water system and Anderson Reservoir. Calero reservoir has a design storage capacity of 10,050 acre-feet at full pool which covers 347 acres. Guadalupe Dam is located in the eastern side of the Santa Cruz Mountains in the Guadalupe River watershed approximately 7 miles southeast of the City of Campbell. The Guadalupe Dam has a drainage area of 5.9 square miles. The reservoir extends 1.1 miles and has a capacity of 3,415 acre-feet and surface area of 74 acres at full pool. The water in Guadalupe Reservoir is used for ground-water recharge along Guadalupe Creek. Lenihan Dam is located in the foothills of the Santa Cruz Mountains in the Los Gatos Creek Watershed approximately 1.5 miles south of the City of Los Gatos. It has a drainage area of 36.9 square miles. The reservoir has a length at full capacity of 2.5 miles, extending south into the Los Gatos Creek basin. Briggs Creek is also tributary to the reservoir. Lexington Reservoir has a storage capacity of 19,044 acre-feet and a maximum surface area of 412 acres. The water in Lexington Reservoir is stored for release to Vasona Reservoir and for ground-water recharge. Vasona Dam is located at the base of the Santa Cruz Mountains in the Los Gatos Creek sub-watershed of the Guadalupe Watershed, approximately 3.5 miles downstream of Lenihan Dam in the town of Los Gatos. The reservoir covers 53 acres and contains 495 acre-feet at capacity. The water impounded in Vasona Reservoir is used for ground-water recharge in the stream bed of Los Gatos Creek. SAN TOMAS AQUINO CREEK WATERSHED The 45-square mile San Tomas Aquino Creek watershed is drained by San Tomas Aquino Creek and its two primary tributaries, Saratoga Creek and Smith Creek. The steep, undeveloped Santa Cruz Mountain headwaters transition to a low-gradient, heavily-urbanized main stem that flows through the cities of Campbell and Santa Clara and discharges to Guadalupe Slough. Winter flows in San Tomas Aquino Creek are flashy due to the high proportion of impervious surface coverage and the creek is usually dry during summer months. The only District dam within this watershed is the Rinconada Treated Water Reservoir Dam which serves to store water for the adjacent Rinconada Water Treatment Plant. Rinconada Treated Water Reservoir Dam is located in the City of Los Gatos. Unlike all other dams discussed here, water entering the reservoir comes completely from piped sources, rather than the surrounding watershed. The water contained within the reservoir has already been treated and is available to be distributed to retail and municipal water systems. Although the Rinconada Treated Water Reservoir Dam sits within the drainage area of Smith Creek, it is hydrologically isolated. STEVENS CREEK WATERSHED The Stevens Creek Watershed with its headwaters in the northeast-facing slopes of the Santa Cruz Mountains drains a watershed of approximately 48 square miles in a generally west to east direction. The two major creeks of the watershed are Permanente Creek and Stevens Creek. Along Stevens Creek is Stevens Creek June 2011 Page 3-132

185 Section 3.4 Hydrology and Water Quality CHAPTER 3 Reservoir, with a drainage area of 17.5 square miles. In the 1960 s a diversion was built along Permanente Creek which contributes winter runoff discharge to Stevens Creek approximately 6 miles downstream of Stevens Creek Dam. The upper watershed is composed of open space and low density residential while the lower watershed on the valley floor is heavily urbanized. Stream hardening has occurred along the lower reaches of Permanente Creek and short segments of Stevens Creek. At the lowest reaches the waters of the Stevens Creek Watershed become brackish and saline before discharging into San Francisco Bay. Stevens Creek Dam is located at the base of the Santa Cruz Mountains in the Stevens Creek watershed, approximately 4 miles northwest of the town of Saratoga, within Stevens Creek County Park. The reservoir has a total length at full capacity of 1.1 miles extending south into Stevens Creek basin. The reservoir has a storage capacity of 3,138 acre-feet and covers 92 acres at full pool. Water stored in Stevens Creek Reservoir is used for ground-water recharge. UVAS CREEK WATERSHED The Uvas Creek watershed drains an approximately 90-square mile watershed originating at Loma Prieta on the east slopes of the Santa Cruz Mountains and ending at the confluence of Uvas Creek with the Pajaro River, southeast of the City of Gilroy. The watershed is primarily open space and low density residential/agricultural land with little alterations to the natural stream flow except where Uvas Creek is dammed in the Santa Cruz Mountains approximately 15 miles upstream of Gilroy to form Uvas Reservoir. Uvas Creek above the reservoir is perennial; flows downstream of the dam are regulated by the District. Summer dry season reservoir releases are adjusted to the percolation capacity of the upper reach, with a dryback reach forming for a portion of the lower reaches of Uvas Creek from mid- to late summer. Uvas Dam is located along the eastern side of the Santa Cruz Mountains approximately 8 miles northwest of the City of Gilroy and 5 miles southwest of the City of Morgan Hill. The reservoir has a total length (at full capacity) of about 2.2 miles extending north into Uvas Creek basin. Uvas Reservoir has a storage capacity of 9,835 acre-feet and a maximum surface area of 288 acres. Eastman Canyon Creek is a tributary to the reservoir. Water stored in Uvas Reservoir is used for groundwater recharge within Uvas and Llagas watersheds. The Uvas Creek watershed yields more runoff than the adjacent Llagas Creek watershed. Water is often piped from Uvas Reservoir to Llagas Creek percolation zones via the Uvas/Llagas Transfer Pipeline. This practice may be modified for steelhead management considerations in Uvas Creek. LLAGAS CREEK WATERSHED Llagas Creek watershed covers an area of 104 square miles, north of and adjacent to the Uvas Creek watershed. Llagas Creek originates on the east slopes of the Santa Cruz Mountains at Loma Prieta Peak. Llagas Creek flows east of Morgan Hill through the low to medium-density residential Paradise Valley, before joining the Pajaro River southeast of Gilroy. Much of the upper watershed is underlain by June 2011 Page 3-133

186 Section 3.4 Hydrology and Water Quality CHAPTER 3 Franciscan serpentines resulting in magnesium-calcium bicarbonate type water. Llagas Creek is dammed in its upper reaches in the Santa Cruz Mountains forming Chesbro Reservoir. Flow releases from Chesbro Dam are regulated by the District. Chesbro Dam is located along the eastern side of the Santa Cruz Mountains in the Llagas Watershed approximately 3.5 miles north of the Uvas Dam and 2.5 miles west of the City of Morgan Hill. It has a total length (at full capacity) of about 2.4 miles extending northwest into the Llagas Creek basin. Chesbro Reservoir has a storage capacity of 7,945 acre-feet and a maximum surface area of 283 acres. Chesbro Reservoir was designed as a multi-purpose facility for water conservation and flood management Water Quality GROUNDWATER QUALITY The District has been monitoring the quality of groundwater in Santa Clara County since the 1940s. The current General Groundwater Quality Monitoring Program includes a network of about 60 wells, which are sampled regularly for general minerals, trace metals, and physical characteristics (Reymers and Hemmeter 2001). Groundwater in the developed portions of the Santa Clara Valley aquifer is of good quality, is relatively uniform, and is currently considered suitable for most beneficial uses (Reymers and Hemmeter 2001). Drinking water standards are met at public water supply wells without the use of treatment methods. Groundwater quality and chemistry are influenced by source waters (infiltration), the geologic substrate of the aquifer, interactions between adjacent groundwater sources, and management activities. The natural background chemical signature of the groundwater is a reflection of the source water and how it becomes altered as it passes through the substrate. Average total dissolved solids concentration ranges from 366 to 396 milligrams per liter (mg/l) in the principal (confined) zone of the Santa Clara Valley aquifer and is high in calcium carbonate. Groundwater near the recharge area (forebay) has a higher magnesium concentration due to the stronger influence of serpentine soils and bedrock. Water quality problems typically result from human activities. Saltwater intrusion, resulting from over withdrawals and historical land subsidence, contributed salts to portions of the Santa Clara Valley aquifer. Although land subsidence had been brought to general abeyance since 1969, the water quality impacts are still evident in the San Francisco Bayfront area. Portions of the Santa Clara Valley sub-basin are somewhat degraded in terms of total mineral salt content. Application of fertilizers can introduce nitrate to groundwater. Because nitrate is generally not filtered out by soil particles, reducing further loading of nitrate is the primary means of protecting groundwater and has been identified as an objective of the District. Nitrate levels in the principal zone of the Santa Clara Valley aquifer ranged from 15 to 18 mg/l between 1997 and 2000; whereas nitrate levels in the Coyote sub-basin ranged from 12 to 38 mg/l and levels in the Llagas sub-basin ranged from 44 to 47 mg/l, often exceeding the drinking water standard of 45 mg/l (SCVWD 2001b). Typical urban and residential pollutants such as metals and oil and grease can impact groundwater; however, infiltration processes have been effective at removing these pollutants such that groundwater meets drinking water standards. Although spills June 2011 Page 3-134

187 Section 3.4 Hydrology and Water Quality CHAPTER 3 and poor management of industrial chemicals and wastes can pose a potential threat to groundwater quality, these types of chemicals are rarely detected in public water supply wells (Reymers and Hemmeter 2001). SURFACE WATER QUALITY The quality of surface waters in the project area varies widely due to inherent differences in local geology, land use patterns, and other watershed conditions. Furthermore, the availability and quality of data differs significantly for different streams and reservoirs according to their importance to the District, their use as habitat for sensitive species, and the year, season and purposes of sample collection, rendering simple comparisons between streams problematic. In general, surface waters can be differentiated by their topographic location. Headwater streams are supplied primarily by surface runoff during the wet season. However, during the dry season, springs (if present) can be an important contributor to water quality. Reservoirs and other impoundments capture runoff from local drainages and are often used to store imported waters. The relative proportion of each source is dependent in part on District management decisions, and the quality of water in streams downstream of reservoirs can vary depending on how the reservoirs are operated. Imported water can have a strong influence on water quality in the project area. The District imports water from the South Bay Aqueduct and the San Luis Reservoir, both of which receive water from the Delta. Imported water from these sources can be routed around the District according to supply and demand. The District routinely discharges imported water into streams and reservoirs to augment local sources and for groundwater recharge purposes. Similar to groundwater, surface water quality problems typically result from human activities. The Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP) has identified seven pollutants of concern in local urban runoff: copper, nickel, mercury, pesticides, polychlorinated biphenyls (PCBs), dioxin compounds, and sediment. Additional potential pollutants were identified in the Drinking Water Source Assessment for Anderson and Calero Reservoirs (SCVWD 2004b): pathogens and nutrients from residential wastewater systems and grazing activities; fuel contaminants from recreation and leaking underground storage tanks; and volatile organic compounds (VOCs) from industrial uses. Other watersheds within the study area likely have similar risks. It should be noted that most District reservoirs are located upstream of the majority of contaminant sources, particularly urban and residential development. One of the major water quality issues currently facing the District is legacy mercury pollution in the Guadalupe River watershed. The New Almaden mercury-mining district, which was active from 1846 to 1975, released mercury into the environment. Mercury is transported with sediments to streams and eventually to reservoirs. Once in the reservoir, the relatively insoluble particulate mercury sulfide undergoes biogeochemical reactions and is transformed to the bioavailable methylmercury. These reactions occur in reduced conditions which develop during the summer when the reservoir has reduced mixing in the water column, thermally stratifies and limited photosynthesis at depth leaves oxygen depleted water at the bottom of the reservoir June 2011 Page 3-135

188 Section 3.4 Hydrology and Water Quality CHAPTER 3 from the innate biological oxygen demand. Reservoir releases can have higher methylmercury concentrations than average reservoir concentrations because the outlet pipes pull from zones low in the water column where oxygen concentrations are lower. (TetraTech 2005) The District monitors water quality at several reservoirs, its water treatment plants, and at selected locations along pipelines. Water quality is quite similar in the reservoirs. Serpentine deposits, which are extensive in areas draining to Chesbro, Almaden, Calero, and Guadalupe Reservoirs, generate waters high in magnesium and sometimes nickel. Sulfide concentrations can increase in the summer when the reservoirs become stratified and produce a characteristic rotten egg odor which is sometimes noted at some reservoir outlets. Algal blooms also tend to develop in most reservoirs in the late spring and summer, preferring warm, non-turbulent water that is rich in nutrients. Reservoirs tend to produce an attenuated flush of turbid water during winter storm periods. Runoff from the upper watershed can move suspended fine sediments into the reservoir. Additionally, the wind action, wave action and higher runoff can mobilize fine sediment along the exposed reservoir basin. The turbulence from the weather conditions acts to keep these particulates suspended or re-suspended in the water column over an extended period, relative to a storm runoff event. Water passing through the reservoir to the downstream reaches may have a more protracted turbidity regime between runoff events as a result Flood Potential Regional flooding in Santa Clara County during storms has been a long and continuing problem. Approximately 60 square miles of the 300-square mile Valley floor is flood prone (Santa Clara County 1994). Levees have been constructed to contain flood flows along some creeks, although flood control measures have demonstrated varying effectiveness. In recent years, major floods have struck in 1952, 1955, 1982, 1986, 1995 and Over the last 20 to 30 years, the amount of urban development in flood prone areas has dramatically increased the estimates of potential property damage from major flooding. Increased impervious surface coverage from development exacerbates flooding problems by increasing total stormwater runoff (Santa Clara County 1994). The District is responsible for flood management in creeks and major drainage channels within Santa Clara County. Local drainage systems, such as storm drains, are the responsibility of cities and counties. The conveyance capacity of channels is maintained and enhanced through implementation of the District s Stream Maintenance Program. With the exception of Rinconada Treated Water Reservoir Dam, the District s dams provide some flood protection; however, relatively small outlet capacities limit the District s ability to quickly alter operations in response to flood emergencies. The dams were designed to augment water supply where water captured during the rainy winter is released during the summer to allow year around percolation into the groundwater basin. By fall, the reservoirs are at a low level which allows the reservoirs to capture runoff early in the rainfall season. June 2011 Page 3-136

189 Section 3.4 Hydrology and Water Quality CHAPTER 3 Although the National Weather Service is responsible for flood warnings, the District assists the process by maintaining and providing access to data generated by the Automated Local Evaluation in Real Time (ALERT) system. The District s ALERT system is a network of 44 rain gages, 38 streamflow gages, 11 reservoir gages and one weather station. Data are made available on the District s website. In addition to real time stage, streamflow and rainfall data, the District publishes flood hazard threshold information for several ALERT stations. The stream conveyance or reservoir capacity of these systems is listed with current levels. Flood thresholds are identified for Anderson, Coyote, Calero, Almaden, Guadalupe, Lenihan, Vasona, Stevens, Uvas, and Chesbro REGULATORY SETTING Federal and State FEDERAL CLEAN WATER ACT Section 303 of the federal CWA and the State s Porter-Cologne Water Quality Control Act establish water quality objectives for all waters in the State. These objectives are implemented locally through Water Quality Control Plans and the National Pollutant Discharge Elimination System (NPDES) permitting program. Section 404 of the CWA additionally gives the USACOE authority to regulate discharges of dredged or fill material into Waters of the United States State CALIFORNIA TOXICS RULE On May 18, 2000, the US EPA published the California Toxics Rule (CTR) in the Federal Register, adding Section to Title 40 of the CFR and establishing new water quality objectives for some constituents in the Basin Plans. On May 22, 2000, the Office of Administrative Law approved, with modifications, the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (Phase 1 of the Inland Surface Waters Plan and Enclosed Bays and Estuaries Plan). The Policy establishes implementation procedures for three categories of priority pollutant criteria or water quality objectives. These are: (1) criteria promulgated by the US EPA in the National Toxics Rule that apply in California, (2) criteria proposed by the US EPA in the California Toxics Rule, and (3) water quality objectives contained in RWQCB water quality control plans (basin plans). NPDES PERMITTING The US EPA has delegated management of California s NPDES Municipal Stormwater Permit program to the State Board and the nine Regional Board offices. The District is signatory to the joint Santa Clara city-county NPDES Municipal Stormwater Permit, which regulates urban runoff discharges from municipalities based on the 1987 amendments to the CWA [Section 402(p)]. Since the first five-year permit was issued in 1990, the SCVURPPP has successively implemented a series of comprehensive stormwater management plans for urban runoff management meeting Regional Board standards. June 2011 Page 3-137

190 Section 3.4 Hydrology and Water Quality CHAPTER 3 When the permit was renewed in 2001, the RWQCB included new design standards for runoff treatment control measures from new development and significant redevelopment. The reissued permit also required development of a Hydrograph Modification Management Plan to manage increased peak runoff flows and volumes (hydromodification) and avoid erosion of stream channels and degradation of water quality caused by new and redevelopment projects. The permit was issued to cover surface runoff generated from various land uses in all the hydrologic sub basins in the basin which discharge into watercourses, which in turn flow into South San Francisco Bay. The permit is a non-point source discharge permit. The existing permit does not cover discharges in the South County where water flows to the Pajaro River and thence to Monterey Bay. In the event that proposed dam maintenance activities disturb more than 1 acre of land (in aggregate), the District would be required to submit a Notice of Intent to the State Board and apply for coverage under the NPDES Construction General Permit. Administration of these permits has not been delegated to cities, counties, or Regional Boards but remains with the State Board. Enforcement of permit conditions, however, is the responsibility of Regional Board staff. Regular maintenance activities performed to restore the original line, grade, or capacity of a facility are not subject to this permit. For other grading activities greater than one acre in size, the District is required to prepare a Stormwater Pollution Prevention Plan (SWPPP) and submit it for review prior to commencing grading. The SWPPP details the site-specific BMPs to control erosion and sedimentation and maintain water quality during the construction phase. The SWPPP also contains a summary of the structural and non-structural BMPs to be implemented during the post-construction period, pursuant to the nonpoint source practices and procedures encouraged by the SCVURPPP and the Regional Board. 303(D) OF THE CLEAN WATER ACT The State of California is required by Section 303(d) of the federal CWA to provide the US EPA with a list of water bodies considered by the state to be impaired (i.e., not meeting water quality standards and not supporting their beneficial uses). The list identifies the pollutant or stressor causing impairment, and establishes a schedule for developing a control plan to address the impairment, typically a Total Maximum Daily Load (TMDL). The TMDL specifies the amount of the target pollutant that the waterbody can sustain on a daily or annual basis and is established by amending the water quality control plan. TMDLs are prepared by the Regional Boards and result in amendments to Water Quality Control Plans which must be approved by the US EPA. Project receiving waters included in the 303(d) list are identified in Table It should be noted that the Llagas Creek listings are largely driven by agricultural influences in the lower watershed, below District facilities. June 2011 Page 3-138

191 Section 3.4 Hydrology and Water Quality CHAPTER 3 The San Francisco Basin Plan was amended on November 16, 2005 by Board Resolution R to establish a TMDL to reduce diazinon and pesticide-related toxicity in Bay Area urban creeks including Coyote Creek, Guadalupe River, Los Gatos Creek, and Stevens Creek (Johnson 2005). The TMDL will become effective upon US EPA approval. Most District reservoirs are upstream of the urban land uses which contribute diazinon. June 2011 Page 3-139

192 Section 3.4 Hydrology and Water Quality CHAPTER 3 Table 3.4-1: Summary of 303(d) Listings for DMP Potential Receiving Waters Impaired Pollutant/ Water Stressor Potential Sources TMDL Note Alamitos Creek Mercury Mine tailings Guadalupe River watershed mercury TMDL Calero Reservoir Mercury Surface mining, mine tailings Guadalupe River watershed mercury TMDL Coyote Diazinon Urban runoff/storm sewers Urban Creek Diazinon TMDL Creek Guadalupe Creek Mercury Mine tailings Guadalupe River watershed mercury TMDL Guadalupe Reservoir Mercury Surface mining, mine tailings Guadalupe River watershed mercury TMDL. Guadalupe Diazinon Urban runoff/storm sewers Urban Creek Diazinon TMDL River Mercury Mine tailings Guadalupe River watershed mercury TMDL Los Gatos Diazinon Urban runoff/storm sewers Urban Creek Diazinon TMDL Creek Stevens Diazinon Urban runoff/storm sewers Urban Creek Diazinon TMDL Creek Llagas Chloride Nonpoint source/point source Low TMDL priority Creek Fecal coliform Pasture grazing-riparian and/or upland, natural sources, nonpoint Low TMDL priority Low dissolved oxygen Nutrients source Municipal point sources, irrigated crop production, agricultural return flows, habitat modification Municipal point sources, agriculture, irrigated crop production, pasture grazing, agriculture-storm runoff, agricultural return flows, urban runoff, storm sewers, habitat modification, nonpoint source, unknown point source Low TMDL priority Medium TMDL priority ph Source unknown Low TMDL priority Sedimentation / Agriculture, hydromodification, Medium TMDL priority siltation habitat modification Sodium Source unknown, nonpoint Low TMDL priority source Total dissolved Nonpoint source, point source Low TMDL priority solids SOURCE: US EPA 2003 June 2011 Page 3-140

193 Section 3.4 Hydrology and Water Quality CHAPTER SIGNIFICANCE CRITERIA The project would have a significant environmental impact to hydrological resources or water quality if it would: Violate any water quality standards or waste discharge requirements or substantially degrade surface or groundwater quality Substantially deplete groundwater supplies or interfere substantially with groundwater recharge Substantially deplete surface water supplies Substantially alter existing drainage courses or patterns of the site or area, including changes to the timing or amount of runoff or alteration of the course of a stream or river, in a manner which would result in substantial erosion, siltation, or stream instability? Contribute runoff water that would exceed the capacity of existing or planned stormwater drainage systems Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam, or place structures within a 100-year flood-hazard area which would impede or redirect flood flows Expose people or structures to a significant risk of inundation by seiche, tsunami, or mudflow IMPACTS AND MITIGATION Impact: Violate Any Water Quality Standards or Waste Discharge Requirements, or Substantially Degrade Surface or Groundwater Quality OVERVIEW A number of maintenance activities will have the potential to introduce pollutants that could violate waste discharge requirements or otherwise degrade water quality. Potential pollutants include sediments or chemicals washed from exposed soils; increased water temperature; and maintenance chemicals such as fertilizers, herbicides, petroleum products, hydrocarbons, paints, and rodenticides. Chemical pollutants also have the potential to violate water-quality standards in groundwater via recharge processes. Any activity that involves ground disturbance can result in erosion, which in turn could adversely affect a range of activities such as the health of sensitive species and the quality of freshwater habitat, adversely affect spawning habitat and reduce the conveyance capacity of channels. The District will implement the following BMPs with all ground disturbing activities to minimize impacts: June 2011 Page 3-141

194 Section 3.4 Hydrology and Water Quality CHAPTER 3 BMP WQ-41: Erosion control methods (e.g., silt fences, straw bale barriers, sediment traps, etc.) would be used as appropriate during maintenance activities. All materials will be removed upon the completion of work. BMP WQ-14: Requires erosion control seeding mixes to be applied to exposed soil surfaces. Almost all DMP activities involve the use of vehicles, which could introduce petroleum products and trace metals through spills, direct contact with waters, or by tracking pollutants from previously traveled surfaces. Potential impacts associated with these types of activities are discussed under Hazards and Hazardous Materials along with standard District BMPs to minimize the risk of hazardous material spills. SURFACES AND/OR EARTHWORK VEGETATION MANAGEMENT Vegetation management has the potential to pollute waterways through increased sedimentation caused by increased erosion through the loss of vegetation, or through the introduction of chemical pollutants. Although the District would first consider non-chemical control methods (BMP HM-2), herbicide control has been identified as a necessary method of vegetation control at dam sites because it is much more effective, and herbicides kill plants and roots, preventing re-growth. Root growth is the primary target because it is the cause of structural damage in dam fill and concrete structures. Herbicides may also be used to eliminate vegetation from weep holes and expansion joints in concrete (e.g., spillways, some upstream dam faces). Fertilizers may also be used to promote growth of desired vegetation following planting or seeding. Use of herbicides would be consistent with the District s policies for herbicide use in The Control of Oversight of Pesticide Use (District ISO procedure Q751D02). The District implements a number of BMPs in implementing its herbicide program: BMP HM-1: All pesticide use will be consistent with approved product specifications and applications made by, or under the direct supervision of, a State certified applicator. BMP HM-4: Posting of areas where pesticides are used will be performed. BMP HM-5: All pest control methods will be performed only after a written recommendation has been prepared by the District s Pest Control Advisor in accordance with requirements of the California Food and Agricultural Code. BMP HM-6: Applications of herbicide would be recorded in the District s CMMS and a report of all products used for pest control run monthly and submitted to the Agricultural commissioner. June 2011 Page 3-142

195 Section 3.4 Hydrology and Water Quality CHAPTER 3 BMP HM-7: Pre-emergence herbicides will not be made to upland areas within 72 hours of predicted significant rainfall. BMP HM-8: Only herbicides and surfactants registered for aquatic use will be applied within the banks of channels within 20 feet of any water present. If rain is forecast then application of aquatic herbicide will be rescheduled. The exposure of soil resulting from vegetation removal is considered a ground disturbing activity, and all BMPs discussed above relating the ground disturbance would be implemented as necessary. With the implementation of standard procedures for herbicide use and ground disturbance, the potential impact to water quality from vegetation removal would be less than significant. Prescribed burns used for the purpose of vegetation management have the potential to increase erosion. Prescribed burns would not necessarily physically disturb soils; however, vegetation prevents some precipitation from falling on the ground surface, and therefore prevents some erosion. Removal of the vegetative cover allows all precipitation to reach the ground surface and can displace soil. Fire also can create a hydrophobic (water repellent) layer below the soil surface that increases erosion of the top layers of soil (Hammond and Clarke 2003). Increased erosion could lead to sedimentation. Revegetation of the area subject to a prescribed burn may be used to minimize erosion; however, where burns are prescribed for propagation of Coyote ceanothus, replanting would not be used. Roots of chaparral species are often not destroyed by fire, which acts to hold soil in place. If additional erosion control is necessary, erosion control measures such as placing straw waddles at the base of the berm, or silt fences would be used (BMP WQ-41) to reduce the potential for erosion. RODENT CONTROL Rodents must be eliminated from burrows on the dam faces and from structures to prevent structural damage and possible interference with valves and other appurtenances. The District may use trapping methods, bait stations, poison bait, fumigants, and shooting to remove rodents. Collapsing and recompacting of empty burrows would occur in all scenarios. Recompaction of burrows has a small potential for causing sediment runoff during the compaction phase, before vegetation has reestablished. The District would utilize ground disturbing BMPs in recompacting burrows. Use of rodenticides, traps, or exclusion gates would not increase sediment runoff. If shooting is used as a method to control ground squirrels, acrylic bullets would be used which would avoid any impacts associated with lead or other metals for bullets. Poison bait pellets containing anticoagulants are placed in bait stations or broadcast in rodent infested areas generally in late spring and early summer, or other times of the year depending on conditions. The baits contain either chlorophacinone which is not soluble in water or diphacinone which is soluble June 2011 Page 3-143

196 Section 3.4 Hydrology and Water Quality CHAPTER 3 in water at 17 parts per million (ppm). The District would comply with restrictions from the US EPA for only using products registered from aquatic use near water bodies, and pesticides listed in the special status species injunction lists would not be used for the DMP unless cleared by US EPA (MM Wildlife-4). Even with regulatory restrictions, there is still a potential to pollute water bodies from the use of anticoagulants. To minimize this potential impact the District will implement MM Water Quality-1, which restricts the District from distributing bait directly to water or if rainfall is predicted in the next 48 hours; requires bait that is not consumed to be removed; and requires carcasses of poisoned animals to be removed daily and disposed of properly. Mitigation Measure MM Water Quality-1: Poison bait containing rodenticides will not be applied to areas inundated by water or distributed when rainfall is forecast in the next 48 hours. Spilled or unconsumed bait will be removed following baiting operations. Dead carcasses of poisoned rodents will be removed daily and disposed of properly. Two types of fumigants may be used: gas cartridges or aluminum phosphide pellets. Gas cartridges produce smoke and carbon monoxide and kill by suffocation. Aluminum phosphide is volatile in water, converting quickly to a gas. As such, fumigants are not expected to cause violations of water quality standards. With the inclusion of standard BMPs and mitigation measures, the use of rodenticides is not anticipated to have a significant effect of water quality. BANK STABILIZATION AND EROSION CONTROL Regrading of slopes may be necessary to repair erosion, restore original grades, and/or to prepare a surface for installation of erosion control materials (e.g., riprap, concrete sandbags). Grading typically involves removal of vegetation and exposure of soils. The District will implement ground disturbing BMPs for these activities. Other BMPs utilized in erosion control projects include: BMP WQ-4: Describes methods to minimize impacts to water quality from storage and transport of sediments (e.g., lining trucks for sediment transport with impervious materials). BMP WQ-5: Requires soil stock piles be maintained and not allowed to enter waterways or a reservoir. BMP WQ-7: Requires the assessment of erosion potential upstream and downstream of work sites and the installation of appropriate structures, such as energy dissipation features. BMP WQ-10: Excludes water from channels until concrete has completely dried. June 2011 Page 3-144

197 Section 3.4 Hydrology and Water Quality CHAPTER 3 BMP WQ-12: Requires the diversion of the entire streamflow around the work area when working in a flowing stream. BMP WQ-18: Requires work sites to be kept orderly and free of debris. Collected debris shall not be allowed to enter storm drains or waterways. All construction-related materials shall be removed upon completion of work. Grading will not be conducted in areas inundated by water or live channels. If necessary, small, temporary coffer dams or other diversion structures will be installed to prevent inundation of work areas (BMP WQ-12). Bank hardening could potentially cause in-stream erosion downstream of the hardened surfaces by transferring energy that was formally absorbed by vegetation or other rough surfaces. The potential hydraulic effects upstream and downstream of the work area shall be assessed prior to initiating bank hardening projects. If necessary, downstream energy dissipaters such as grade control structures or riprap shall be considered (BMP WQ-7). Bank stabilization often requires concrete, which has the potential for chemical leaching and contamination. Portland cement, the main ingredient of concrete, forms calcium hydroxide (Ca(OH) 2 ) when dissolved in water. Calcium hydroxide is highly alkaline and raises the ph of water causing direct damage to fish and other aquatic species. High ph can also increase the toxicity of other substances in water such as ammonia. For these reasons, the District isolates wet concrete from water (BMP WQ-10). If necessary, a coffer-dam or other diversion structure would be temporarily installed to prevent inundation (BMP WQ-12). With the implementation of the above BMPs, installation of bank stabilization materials and erosion control efforts would not result in significant impacts to water quality and would have overall beneficial impacts by reducing downstream erosion from unstable banks. ROAD AND BOAT RAMP MAINTENANCE District managed roads may require grading to even gravel bases, correct erosion and roadside gullies, clear landslides, and/or provide retaining walls. Grading work typically entails ripping/grading the existing roadway to break up and loosen the existing gravel, adding more fill (if necessary), and then compacting the surface with a roller. Roadwork would not include paving or use of tar or asphalt. Roads blocked by landslide materials must be cleared of debris and the unstable slope must be stabilized with nets, concrete walls, riprap, retaining walls, or other measures. Access road work would include construction of temporary access roads to gain vehicle and equipment access to exploration sites, which are typically located on or near to dam faces. BMPs will be applied as appropriate to prevent erosion, stockpiles will be managed to prevent runoff to streams and reservoirs, temporary access roads will be removed, and disturbed areas will be revegetated with grasses, according to BMP WQ-4. Erosion control BMPs (i.e., BMP WQ-5, BMP WQ-7, and BMP June 2011 Page 3-145

198 Section 3.4 Hydrology and Water Quality CHAPTER 3 WQ-12 [previously described above]) would all be implemented to minimize impacts from ground disturbance associated with road and boat ramp maintenance activities. Boat ramp repair would be performed when the reservoir water level is low enough to prevent ramp repair materials from falling into or contaminating the reservoir. Boat ramp work could require the use of concrete. BMP WQ-10 would be implemented to ensure that wet concrete would not degrade water quality in the reservoir. The impacts from road and boat ramp maintenance would be less than significant. DEBRIS REMOVAL Debris removal includes hauling waste that can range from paper trash to large appliances that have been illegally dumped at the dams. Debris removal also includes removal of woody vegetation debris that has accumulated along the upstream dam face. Woody debris may be crushed at the dam site after being stockpiled in a previously disturbed area and kept away from waterways. Graffiti removal is part of the debris removal maintenance activity. Spillways, concrete dam faces, buildings, and other facilities are often vandalized with graffiti, which is removed by repainting. Paints could be over sprayed, spilled, or washed into receiving waters. Water-quality standard violations would be prevented by following District guidelines on spill prevention as discussed in Hazards and Hazardous Materials. Debris removal would have a less than significant impact on water quality. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures includes maintenance of equipment such as the hydraulic systems, inlet and outlet structures, inlet/outlet valves, outlet pipe and tunnel, concrete structures, fish screens, and other accessory structures connected to the dam. Maintenance can vary from repairing or cleaning structures to replacing parts. Maintenance also includes clearing accumulated sediment from the inlet structure and hydraulic system by bringing the sediment to the surface for disposal. It may be necessary to close inlets and/or outlets for up to six months to conduct maintenance and repair activities. Flows from the reservoirs under normal conditions contribute to what has become the natural flow within the creeks. Cessation of flows could have a potentially significant effect on water quality in the stream. If the maintenance activities would result in cessation of downstream flows, MM Wildlife-1 would be implemented to maintain flow rates and/or temperature in the downstream receiving water so as to not significantly affect water quality parameters. Specific flow (and/or temperature) criteria for the flow bypass system differ according to reservoir, receiving water, and season. However, flow bypass generally entails collecting water from an adequate depth in the reservoir and pumping it to the dam spillway or plunge pool. The bypass system would be designed such that temperature (if feasible) and turbidity remain within 80 percent of baseline conditions measured approximately 400 feet downstream of the outlet, in accordance of the mitigation measure. June 2011 Page 3-146

199 Section 3.4 Hydrology and Water Quality CHAPTER 3 Concentration of flows at the pipe outlet could result in erosion. Transition back to normal reservoir releases could result in surge flows, which may erode stream banks. MM Wildlife-1 calls for gradual ramping of water flows during diversions or flow bypass, and would be implemented to prevent scouring of the channel bed and banks. The measure also contains provisions that include the use of erosion control methods to prevent siltation from the inlet area of the reservoir or where the water is released out of the flow bypass piping downstream of the dam (within the stilling pool). Energy dissipaters would be used to reduce the erosive force of the flow bypass system and a ramping program will be employed to avoid surge flows during the transition between flow rates. Impacts would be less than significant with the inclusion of the mitigation measure. Removal of sediments that have accumulated underwater around inlets and other structures (e.g., hydraulic lines) may be necessary to maintain operation and/or gain access for maintenance or repair activities. If possible, sediment removal would be conducted when the reservoir levels are below normal average low levels and the inlets are exposed above water. Sediment would be removed using loaders or other equipment. If sediment removal must be conducted when the area is underwater, dredging will be used. BMPs would be employed (BMP WQ-4 and BMP WQ-5) to minimize stockpile runoff to waters outside of the work area. Sediments collected from Almaden, Calero and Guadalupe Reservoirs could be contaminated with mercury, which could significantly affect water quality from runoff through the sediment if improperly disposed. Sediments from the Guadalupe watershed would be tested for mercury content to determine the appropriate handling and landfill destination according to MM Hazards-2. Sediment removal would not have a significant effect with implementation of MM Hazards-2. Seepage monitoring pipes and small collection boxes equipped with weirs are located on the downstream faces of the dams to collect and monitor seepage through the dams. Soils could be disturbed and eroded when these structures are maintained or when new structures are installed. These activities would be conducted using standard ground disturbance BMPs (BMP WQ-5, BMP WQ-7, and BMP WQ-12). These effects would not be significant and no mitigation is required. There is a small potential for hydraulic lines to spill during maintenance. These spills would be localized and of limited extent due to the small volume of hydraulic fluid in these lines. If hydraulic fluid is released to water during maintenance activities, the District would attempt to contain spilled fluid would booms and absorbent materials. Guidelines set forth in the District s Hazardous Materials Business Plan (HMBP, further discussed in Section 3.5, Hazards, Hazardous Materials, and Human Health and Safety) are followed to reduce the likelihood of accidental spills and provide a plan of action in the event of a spill. These guidelines are implemented by BMPs HM-12, HM-13 and HM-14 to minimize potential effects from hydraulic fluid spills, and impacts would be less than significant. Concrete structure repair may include patching cracks and replacing large panels on spillways, dam faces (Calero, Almaden, Guadalupe, Vasona, and Stevens), dragon s June 2011 Page 3-147

200 Section 3.4 Hydrology and Water Quality CHAPTER 3 teeth 18 (Vasona and Coyote Percolation Ponds), blockhouses, outlet channels, and plunge pools. Concrete work would be conducted during the dry season when rainfall is not in the forecast. Wet concrete would be isolated from water for a period of two weeks or until it no longer poses a threat to water quality (BMP WQ-10). If necessary, a coffer-dam or other diversion structure would be temporarily installed to prevent inundation (BMP WQ-12). Impact to water quality from concrete repair would be less than significant. Maintenance activities at other appurtenance structures could require the use of chemicals such as lubricants and paints. Measures to avoid or minimize the accidental release of chemicals to receiving waters are discussed in Section 3.5 (Hazards, Hazardous Materials, and Human Health and Safety). INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring generally would involve visual surveys of the dam facilities and surrounding equipment by District and agency personnel. Inspections often involve exercising radial gates and/or inlet/outlet valves. Impacts from inspections and monitoring are minimal as inspections and monitoring are usually performed on the ground and do not require disturbance. Exercising of the inlet valves would have the potential for release of hydraulic fluid. Exercising of the radial gates would have the potential for the release of lubricating oil. District personnel always carry spill clean-up kits when operating the valves and radial gates, which require use of the hydraulic fluid. Any hydraulic fluid spills are cleaned up immediately according to the HMBP. Exploratory work could include boring and excavation anywhere on or around the dam, which could also involve temporary access roads and filling and compaction of excavations. Exploratory borings would generate piles of soils, water, and rock typically referred to as cuttings. These materials could be washed into receiving waters during storm events. BMP WQ-4 and BMP WQ-5 describe appropriate methods for the handling and storing disturbed sediments and soil stockpiles and installation of appropriate erosion control materials. The District also implements specific BMPs for well and exploratory borings. BMP WQ-37 defines how the District handles cuttings, and BMP WQ-39 defines procedures for the destruction of exploratory borings. BMP WQ-18 outlines actions necessary for the complete cleanup of work sites. These BMPs would minimize potential impacts from maintenance activities. Impacts from exploratory work would be less than significant. RESERVOIR DEWATERING Dewatering has the potential to adversely impact water quality in the creeks downstream. Water quality impacts resulting from dewatering could include the reduction in the volume of water, increased water temperature, and increased turbidity. 18 Dragon s teeth are concrete post-like structures, approximately two feet in height, set in a line into the ground or spillway apron which serve to dissipate the energy of flows. June 2011 Page 3-148

201 Section 3.4 Hydrology and Water Quality CHAPTER 3 Dewatering has the potential to reduce flow in the downstream reaches when the storage volume is reduced or eliminated and bypass flow only is applied in these stream reaches. The low flow condition may yield reduced water quality from stagnation where the flow volume does not produce the normal velocity and mixing. This would be expected to be particularly visible where the bypass flow does not produce flushing against other stream inputs or where the streamflow is percolating to dryback downstream at the bypass flow rate. Water temperature may increase as the storage volume is reduced and the normal stratification process does not occur. During partial or complete dewatering, bypass of inflow during a dewatered condition may increase the thermal loading of the bypass water. Either of these may promote higher temperature or longer periods of higher temperature in the downstream reach compared to the normal operations. This may impact beneficial uses (e.g. COLD, SPAWN, RWQCB Basin Plan) of stream reaches. Accelerated releases of stored reservoir water to rapidly drain the reservoir may increase the scour potential of stream flow downstream thus increasing erosion. This may be compounded if it is taking place during natural storm runoff events. Dewatering also has the potential to increase turbidity in the downstream reaches of the stream when the (fully) exposed reservoir basin is subject to additional erosion and mobilization of fine sediments during the early stages of refilling the reservoir. The District would minimize the negative impacts of reservoir dewatering on water quality or sediment quality through implementation of MM General-3, which requires the development a dam-specific reservoir dewatering plan. Flow rates, erosion and turbidity controls and other water quality measures would be incorporated into individual dewatering plans. The plans would also identify alternative sources of water to maintain adequate water quality in the impacted creek. Additional research or studies may be required prior to implementation of any dewatering plans, and a subsequent environmental assessment may be necessary. The requirements of MM General-3 would insure that potential water quality impacts are reduced to a less than significant level Impact: Substantially Deplete Groundwater Supplies or Interfere Substantially With Groundwater Recharge Groundwater resources would not be significantly impacted as a result of standard maintenance activities. Most maintenance activities included in the DMP would not require groundwater pumping. Supplemental water may be needed to mitigate for reservoir water that is unavailable during reservoir dewatering, allowing downstream reaches to remain wetted. Supplemental sources may include pumped groundwater or other sources. However, most reservoirs will have other options available for supplemental water besides groundwater and much of the supplemental water would be recharged into the groundwater basin for future use as are all releases from the reservoirs. See Chapter 3.13, Utilities and Services Systems. Water supply is one of the factors to be examined under MM General-3 for reservoir dewatering. The project does not include substantial increases in impervious surfaces that could hinder groundwater recharge. June 2011 Page 3-149

202 Section 3.4 Hydrology and Water Quality CHAPTER 3 Reservoir water is used, especially in the summer and fall months, to augment downstream flows. This augmentation is designed to enhance groundwater recharge within the stream and provide supply that is rediverted off stream for additional groundwater recharge (at the same time producing aquatic habitat function). Closing of the inlet/outlet valves for maintenance activities can cease flows to the downstream area and could thus impact recharge. DMP actions that require reservoir dewatering would produce a temporary interruption in the groundwater recharge operation at facilities being supplied by that reservoir until it is refilled and placed back into normal operations. However, the District maintains a diverse portfolio of groundwater recharge facilities throughout the County. Water is stored as groundwater for later use by actively replenishing the basin when water is plentiful, and the District uses imports from both the State Water Project and federal Central Valley Project to meet groundwater recharge needs. The DMP would have a less than significant impact on groundwater supplies and recharge Impact: Substantially Deplete Surface Water Supplies Regular maintenance activities would have no impact on surface water supplies. Only two reservoirs are directly used as a surface water supply: Anderson and Calero Reservoirs, and these sources are typically only minor contributors to the overall water supply. In the event that one of these two reservoirs would need to be dewatered, water would be released over a period of time to allow the District to capture most of this water downstream for groundwater recharge. The District also maintains a diverse portfolio of water supply; if Anderson or Calero Reservoirs were not available as a water source, groundwater, imported sources and the remaining reservoirs would still be available. See Chapter 3.13, Utilities and Services Systems, for more detailed discussion of water supplies. The impact to surface water supplies would be less than significant Impact: Alter Existing Drainage Courses or Patterns of the Site or Area, Including Changes to the Timing or Amount of Runoff or Alteration of the Course of a Stream or River, in a Manner Which Would Result in Substantial Erosion, Siltation, or Stream Instability Maintenance activities would not alter existing drainage patterns. The objectives of maintenance activities are to ensure public safety and continued reliability of the dam structures, the DMP does not include the expansion or major alteration of the facilities. The maintenance and repair of existing facilities and structures would not alter the amount or timing of runoff from any of the sites in the APE Impact: Contribute Runoff Water That Would Exceed the Capacity of Existing or Planned Stormwater Drainage Systems Stormwater at the sites drains along the natural topography either into the reservoir or into the creek below the dam; stormwater facilities are not required for the dams. There would be no impact to stormwater drainage systems. June 2011 Page 3-150

203 Section 3.4 Hydrology and Water Quality CHAPTER Impact: Expose People or Structures to a Significant Risk of Loss, Injury or Death Involving Flooding, Including Flooding as a Result of the Failure of a Levee or Dam, or Place Structures Within a 100-Year Flood-Hazard Area Which Would Impede or Redirect Flood Flows The intent of the DMP is to keep the dams and appurtenances in working condition, thereby reducing the risk of loss, injury or death involving flooding as a result of the failure of a levee or dam. The maintenance activities will not increase the amount of surface runoff or alter drainage patterns which could exacerbate a flood hazard. No new structures would be constructed in a flood zone. Water for dewatering would be released over a period of time which would be designed not to exceed a two-year rain event and would not result in flooding. Dewatering would be halted in the event of a large rain event so as to not contribute to any potential flooding Impact: Expose People or Structures to a Significant Risk of Inundation by Seiche, Tsunami, or Mudflow The dams are located well inland and at elevations that are not at risk from tsunami. The dams are engineered structures designed to protect the public from any threat of seiche or mudflow. The DMP would ensure that the District s dams are continued to be operated to ensure the public safety MITIGATION MEASURES MM Water Quality-1: Poison bait containing rodenticides will not be applied to areas inundated by water or distributed when rainfall is forecast in the next 48 hours. Spilled or unconsumed bait will be removed following baiting operations. Dead carcasses of poisoned rodents will be removed daily and disposed of properly. MM Wildlife-1: (previously listed in Section 3.3 Wildlife) MM General-3: (previously listed in Section 3.3 Wildlife) MM Hazards-2: (listed in Section 3.5 Hazards and Hazardous Materials and Human Health and Safety) Residual Impacts After Mitigation All impacts would be reduced to less than significant levels with implementation of the mitigation described here. June 2011 Page 3-151

204 Section 3.4 Hydrology and Water Quality CHAPTER 3 Best Management Practices (See the Mitigation Monitoring and Reporting Program (Appendix V) for complete text of BMPs) WQ-4: Handle Sediments so as to Minimize Water Quality Impacts WQ-5: Avoid runoff from Soil Stockpiles WQ-7: Prevent Erosion Downstream of Bank Protection Sites WQ-10: Evaluate and Select the Most Appropriate Use of Concrete Near Waterways WQ-12: Divert/Bypass Water at non-tidal Sites WQ-14: Use Temporary Seeding for Erosion Control as Appropriate WQ-18: Maintain Clean Conditions at Work Sites WQ-37: Manage Well or Exploratory Boring Materials WQ-39: Backfill or Otherwise Destroy Exploratory Borings WQ-41: Prevent Stormwater Pollution UT-1: Manage Sanitary/Septic Waste June 2011 Page 3-152

205 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER HAZARDS, HAZARDOUS MATERIALS, AND HUMAN HEALTH AND SAFETY ENVIRONMENTAL SETTING Fire Hazards Much of the project area is subject to fire hazards. The mountainous lands in the eastern and western sections of the project area are highly susceptible to wildland fire hazards. The fire hazards result from a variety of factors, including large accumulation of natural fuels, inaccessibility, and climatic influences (such as wind). City and County fire departments and the Santa Clara Unit of the California Department of Forestry and Fire Protection (CAL FIRE) provide fire protection in the project area. CAL FIRE provides wildland fire protection in State Responsibility Areas (SRA), which consist mostly of privately owned forestlands, watershed, and rangelands. There are 555,300 acres of SRAs in Santa Clara County (CAL FIRE 2007). Land within city boundaries and federally owned lands are excluded from SRAs. All dams, except for Vasona Dam and Rinconada Treated Water Reservoir Dam, are located in SRAs. Vasona Dam and Rinconada Treated Water Reservoir Dam are located within the Town of Los Gatos and are served by the Santa Clara County Fire Department. CAL FIRE identifies five types of fire threat based on levels of severity of risk: (1) Extreme, (2) Very High, (3) High (4) Moderate, and (5) Little or No Threat. The dams are primarily located in areas designated as moderate to high risk of fire hazards as shown in Figure (CAL FIRE 2000). CAL FIRE assesses areas within the state for fire hazard risk by examining: The history and intensity of wildfires in the area; Size, and type of vegetation in the area; and Proximity to fire extinguishing resources. June 2011 Page 3-153

206 Figure 3.5-1: Wildland Fire Hazard in Project Area June 2011 Page 3-154

207 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER Hazardous Materials HAZARDOUS MATERIALS RELEASE SITES Hazardous substances have chemical and physical properties that may pose a substantial present or future hazard to human health or the environment when improperly handled, stored, disposed or otherwise managed. These substances are commonly used in commercial, agricultural, and industrial applications, and to a limited extent in residential areas. The only known hazardous material site identified in the vicinity of the dams based on a review of the Cortese List (pursuant to Government Code Section ) is Almaden Quicksilver County Park, at Alamitos Road and Hicks Road (adjacent to Almaden and Guadalupe Reservoirs). Mercury mining and ore processing were conducted by a number of different entities at the New Almaden Mining District from 1845 to 1975 (Bailey and Everhart 1964; Santa Clara County 1994). Mercury was extracted by heating the ore in retorts and furnaces to volatilize the mercury, which was then condensed to liquid mercury. Processed ore (calcines) from the furnaces and retorts was dumped near the processing areas. All mining related operations ceased in 1975 when Santa Clara County purchased the property for use as a park. County Parks is working on remedial actions within the park focusing on calcines at five separate areas: the Mine Hill area, the Hacienda Furnace Yard, the Enriquita Mine Retort, the San Mateo Mine Retort, and Senator Mine. Almaden and Guadalupe dams are not included within any of these remedial action areas Mineral Hazards NATURALLY OCCURRING ASBESTOS Asbestos is a commercial name for a group of minerals that are commonly used in building materials because of their high tensile strength and flexibility. Minerals that have asbestiform habit (long thin hair-like fiber), include those from the serpentine and amphibole mineral groups. The most common type of asbestos found in California is chrysotile, a serpentine mineral; other types include tremolite asbestos and actinolite asbestos which are amphibole minerals. Exposure to asbestiform minerals from inhalation or ingestion can result in severe health problems. Lung diseases from asbestos exposure include asbestosis and mesothelioma, among others. (California Air Resources Board 2008) Asbestos minerals (chrysotile) are known to occur in serpentinite near Lexington Reservoir as documented on the Lime Kiln Trail, less than one mile east of Lenihan Dam (Stoffer and Messina 2002). Both chrysotile and amphibole asbestos can occur in dolostone (also known as dolomitic limestone) which may also be present in the Lenihan Dam area (CGS 2002). Other project areas that potentially have asbestos mineral hazards include the project area around Almaden Dam, Calero Main Dam, Chesbro Dam, and Guadalupe Dam (SCVWD 2005a) June 2011 Page 3-155

208 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 RESIDUAL MERCURY South San Francisco Bay is strongly influenced by the legacy of large-scale mercury mining that occurred in Santa Clara County from Mercury can be found in the sediments that lead down the Guadalupe River drainage through the South Bay to the Golden Gate. Mercury in water and sediment can be present in dissolved or particulate forms. Under certain physical and biological conditions, bacteria can also convert inorganic mercury to the organic form (methylmercury). Methylmercury is the primary concern to human health and the environment due to its greater toxicity and ability to bioaccumulate 19. Factors conducive to mercury conversion to methylmercury (termed methylation) include: Low flow or stagnant waters; Hypoxic 20 or anoxic 21 conditions in the water column; Low ph (< 6); High concentrations of dissolved carbon. Previous studies have shown that mercury concentrations in sediments vary widely from different parts of the Guadalupe Watershed. Most mercury in the freshwater environment is chemically bound to suspended particles of soil or sediment; a smaller fraction is bound to dissolved organic carbon. The potential for adverse environmental effects from sediment-bound mercury depends primarily on transport and depositional characteristics (e.g., particle size), and the physical and chemical properties of the sediment. The Guadalupe River TMDL Project has been established for mercury and calls for a 90 percent reduction in the amount of mercury loading (Tetra Tech 2004). Refer to Section 3.4 Hydrology and Water Quality for further discussion of TMDLs and water quality issues. The Guadalupe Reservoir, Calero Reservoir, and Almaden Reservoir are all located within the Guadalupe Watershed. Sediments within these reservoirs may be contaminated Residual Pesticides OVERVIEW Pesticides 22 are commonly used for vector control and for agricultural uses in Santa Clara County. Table below lists the top 10 pesticides used in Santa Clara County in 2007, as recorded by the Pesticide Action Network (PAN) Pesticide Database (Orme and Kegley 2007). 19 Bioaccumulation is a general term for the accumulation of substances, such as pesticides (DDT is an example), methylmercury, or other organic chemicals in an organism or part of an organism. The accumulation process involves the biological sequestering of substances that enter the organism through respiration, food intake, epidermal (skin) contact with the substance, and/or other means. The sequestering results in the organism having a higher concentration of the substance than the concentration in the organism s surrounding environment (USGS 2005). 20 Hypoxic: Having too little oxygen 21 Anoxic: Without oxygen 22 General term that is inclusive of herbicides and rodenticides June 2011 Page 3-156

209 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 PESTICIDE USE BY THE DISTRICT The District currently uses several herbicides and rodenticides for levee maintenance as part of the SMP that are proposed for use under the DMP. The District also uses some of these rodenticides for limited burrowing rodent control in advance of implementation of the DMP (this use was subjected to environmental review in the Rodent Control MND, approved in 2007). Similarly, herbicides (primarily aquatic formulations of glyphosate) and rodenticides (chlorophacinone and diphacinone) proposed for use in the DMP are currently used in other areas of the District s jurisdiction. The District has made limited use of herbicides or rodenticides in the vicinity of the dams since 2002 (Wallis pers. comm. 2007). Table 3.5-1: Top 10 Pesticides Recorded Use in Santa Clara County in 2007 Chemical Name Chemical Class Use Gross Pounds Sulfuryl fluoride Inorganic Fumigant 175,199 Metam-sodium Dithiocarbamate Fumigant, Herbicide, 113,892 Fungicide, Microbiocide, Algaecide Metam-potassium Dithiocarbamate Fumigant, Fungicide, 111,986 Microbiocide, Algaecide, Nematicide Kaolin Inorganic Insecticide, Adjuvant, 43,988 Fungicide, Microbiocide Glyphosate, Phosphonoglycine Herbicide 36,568 Isopropylamine salt Sulfur Inorganic Fungicide, Insecticide 25,386 Alkyl dimethylbenzyl Quaternary Ammonium Algaecide, Microbiocide 22,700 ammonium chloride Compound Trichloro-s-triazinetrione Triazinetrione Microbiocide, Water 20,734 Treatment Mineral Oil Petroleum derivative Insecticide, Adjuvant 19,237 Chloropicrin Unclassified Nematicide 18,370 SOURCE: Orme and Kegley 2007 Pesticides are applied in conformance with all relevant regulations, standards, and permit requirements. GUADALUPE RIVER CONTAMINATION Studies have shown that sediment along the Guadalupe River contains elevated concentrations of polychlorinated biphenyls and organochlorine pesticides, despite the fact that these compounds have been banned for decades (McKee et al. 2006). These contaminants are considered toxic and extremely persistent in the environment. June 2011 Page 3-157

210 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER REGULATORY SETTING Federal US EPA The US EPA s mission is to protect human health and to safeguard the natural environment. The authority for many of the laws that the US EPA enforces is delegated in California to the RWQCB and the Department of Toxic Substances Control (DTSC). However, the US EPA remains the lead on sites that are included on the National Priority List (NPL). RESOURCE CONSERVATION AND RECOVERY ACT Resource Conservation Recovery Act (RCRA) regulates hazardous waste from the time that the waste is generated through its management, storage, transport, and treatment, until its final disposal. The US EPA has authorized the DTSC to administer the RCRA program in California. SETTLEMENT AGREEMENTS BETWEEN THE US EPA AND THE CBD The CBD reached a settlement agreement with the US EPA to protect the threatened California red-legged frog (Rana aurora draytonii) from 66 pesticides currently authorized for use in California (US EPA 2009a). The agreement, signed in October 2006, and approved by a U.S. District Court, prohibits use of these pesticides in and adjacent to core red-legged frog habitats throughout California until the US EPA completes formal consultations with USFWS to ensure the chemicals are not jeopardizing or contributing to the decline of the species. The agreement is a result of a lawsuit filed by CBD against the US EPA in The Court found in September of 2005 that the US EPA had violated the ESA by registering pesticides for use without considering how they might impact the continued existence of the red-legged frog. The agreement requires the US EPA to: 1. Make effect determinations on the impacts of the 66 pesticides on red-legged frogs within 3 years; 2. Prohibit interim use of the pesticides within and adjacent to red-legged frog habitats, specifically designated critical habitat areas, aquatic features, and upland habitats occupied by the frog; 3. Mandate pesticide-free buffer zones adjoining frog habitats as defined in the injunction (200 feet for aerial pesticide applications to prevent drift and 60 feet for ground applications to prevent runoff); June 2011 Page 3-158

211 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 4. Allow exemptions for public health vector control 23 programs, invasive species and noxious weed programs, and other specific applications that pose little or no risk to frogs; and 5. Distribute an educational brochure for pesticide applicators and county agricultural commissions regarding the red-legged frog, impacts of pesticides and contaminants on frogs generally, and describing the interim restrictions on pesticide use in the settlement. A second complaint was filed by CBD against the US EPA in 2007 enjoining the US EPA from authorizing use of 75 pesticides in and adjacent to core habitats and recorded occurrences of eleven additional federally listed species throughout the Greater San Francisco Bay Area Counties. A stipulated settlement proposed in May 2010 prohibits full licensure for use in these areas until the US EPA completes formal consultations with the USFWS to ensure the chemicals are not jeopardizing or contributing to the decline of these species. Of the list of potentially affected species in this injunction and settlement two are present in project areas: California tiger salamander, and bay checkerspot butterfly. The 2010 agreement requires the US EPA to: Complete formal consultations with USFWS on the impacts of the original list of 75 pesticides on the affected species within 2 years and the complete list by September 30, 2014, including the effects of application of a set of the urban pesticides when applied in areas with impervious surfaces; Prohibit interim use of the pesticides within and adjacent to the named species habitats, specifically designated critical habitat areas, and also additional aquatic features and upland habitats occupied by the species, described per species by the Township, Range and Section of occurrence records; Mandate pesticide-free buffer zones adjoining species habitats (each species requirements are described separately but the most restrictive case includes 600 feet for aerial or ground pesticide applications); and Allow exemptions for other outdoor uses including basal bark or cut stump application to individually treated trees where little or no risk to the named species and application occurs outside of a 60-ft. buffer to named habitat for the named species. 23 Vector control is any method to limit or eradicate the vectors of vector born diseases, for which the pathogen (e.g. virus or parasite) is transmitted by a vector which can be mammals, birds or arthropods, especially insects, and more specifically mosquitoes. June 2011 Page 3-159

212 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 US EPA S PROPOSED RISK MITIGATION DECISION FOR TEN RODENTICIDES The US EPA has issued a proposed decision (US EPA 2009) that restricts the sale and use of commercial rodenticides containing anticoagulant poisons. The US EPA proposes to: 1. Restrict the sale and application of broadifacoum, bromadiolone, and difethialone to registered pesticide applicators. 2. Require six other rodenticides containing anticoagulants for sale to consumers be sold in tamper-resistant bait stations. 3. Require labeling improvements to mitigate the risks associated with the use of these rodenticides to wildlife and children. These chemicals are currently available to consumers in common household products such as DeCon. The purpose of this is to protect non-target wildlife from primary and secondary exposure (US EPA 2009) State CALIFORNIA HEALTH AND SAFETY CODE California law defines a hazardous material as any material that, because of its quantity, concentration, or physical, chemical, or infectious characteristics, may pose a present or potential hazard to human health and safety or to the environment if released in the workplace or the environment (California Health and Safety Code Section 25501). A hazardous waste is defined as a discarded material of any form (e.g., solid, liquid, gas) that may pose a present or potential hazard to human health and safety or to the environment when improperly treated, stored, transported, or disposed of, or otherwise managed (California Health and Safety Code Section 25117). California s RCRA hazardous waste program is more stringent than the federal program and certain wastes that would not qualify as hazardous based on federal standards (termed non-rcra hazardous waste). Handling and storage of fuels, flammable materials, and common construction related hazardous materials are governed by California Occupational Safety and Health Administration (Cal/OSHA) standards for storage and fire protection Local SANTA CLARA COUNTY GENERAL PLAN The Santa Clara County General Plan includes several provisions for protection from hazards. The County has developed the following strategies (Santa Clara County 1994): Strategy #1: Inventory Hazards and Monitor Changing Conditions June 2011 Page 3-160

213 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Strategy #2: Maintain Low Resident Population Densities Within High Hazard Areas Strategy #3: Design, Locate and Regulate Development to Avoid or Withstand Hazards Strategy #4: Reduce the Magnitude of the Hazard, If Possible Strategy #5: Provide Public Information Regarding Natural Hazards BAAQMD, REGULATION 5 The BAAQMD Regulation 5 regulates open burning within the BAAQMD. The Regulation forbids open burning within the District with certain exceptions. Burning woody debris at the District s reservoirs, which capture large woody debris that might otherwise go downstream and potentially restrict flood flows, is considered an exemption for flood control. Regulation 5 states that: Flood Control: Fires set for the purpose of disposal of material, which is lying or growing within natural channels or flood control channels. The fire must be set or allowed by a public official in charge of flood control activities. The fire must, in the opinion of such official, be a necessary incident to the clearing and maintenance of watercourses and flood control channels for preventing or eliminating a flood hazard. Prior reporting pursuant to Section must be made to the Association of Public Safety Communications Officials (APCO) by the person setting the fire. Regulation 5 also requires that local permits also be obtained from the fire department. The Santa Clara County Fire Department does not currently allow burning for any use other than agricultural. SANTA CLARA VALLEY WATER DISTRICT ADMINISTRATIVE POLICIES AND PROCEDURES The Control of Oversight of Pesticide Use (District ISO procedure Q751D02) specifies the process the District uses to evaluate pest control methods, and alternatives to pesticides. Pesticides are one tool for pest control on District properties and facilities. The most common pesticide use is herbicide application to manage vegetation. Pesticide use is evaluated based on: Regulatory restrictions Effectiveness Public health aspects Long and short term environmental impacts Financial cost Consistency with District s policies June 2011 Page 3-161

214 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Standard pesticide use practices are: Only pesticides approved for District use may be used on District facilities. The list of approved pesticides is updated as needed. A State-certified Qualified Applicator with the appropriate current certification categories will provide immediate oversight for application of all pesticides. All pesticide applications performed by employees, contractors, or permittees under the direction of the District on properties and facilities must comply with: Applicable sections of California Food and Agricultural Code for non-crop use; Regulations enforced by the State Department of Pesticide Regulation; CDFG Code relative to stream alterations; Applicable US EPA Regulations; Applicable NPDES permit regulations; Countywide Urban Runoff permit requirements; The pesticide label; Only herbicides registered for aquatic use may be used within the channel banks of a creek, ditch, canal, or percolation pond systems, or within twenty feet of any water present; Herbicides are used only when alternatives to pesticide use such as mowing, hand removal, disking, or grazing are not effective to achieve vegetation management objectives; Rodenticides are used only after trapping to control burrowing rodents proves ineffective or impractical; Products listed on the State Department of Pesticide Regulation (DPR) A list of known groundwater contaminants will not be used. Detailed information on DPR regulations can be found on their web site at Category I and II pesticides will not be used for routine projects without review and approval by the District s Pesticide Review Team; and No organophosphate or carbamate products may be used. June 2011 Page 3-162

215 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER SIGNIFICANCE CRITERIA The project would cause a significant impact from hazards and hazardous materials if it would: Result in a significant risk of loss of property or life due to wildfires Expose individuals to or compromise the environment through emission of or exposure to hazardous materials, substances, or wastes Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within ¼ mile of an existing or proposed school Create a significant hazard to the public or the environment from existing hazardous material contamination on site or nearby Result in a substantial safety hazard for people residing or working in the project area located within two miles of an airport, or to aircraft utilizing the airport IMPACTS AND MITIGATION Impact: Result in a Significant Risk of Loss of Property or Life Due to Wildfires OVERVIEW Most District dams are located in natural areas with dam faces and surrounding areas covered by vegetation. Project activities present some risk of igniting wildfires. Certain activities (such as welding) have the potential to spark wildfires. Smoking on breaks presents a risk of initiating a wildfire in rural grassland areas. Improper storage or use of fuel could also ignite a fire. MM Hazards-1 is implemented to minimize the risks of fire. MITIGATION MEASURE MM Hazards-1: For all work elements of the DMP the following fire prevention measures will be implemented to reduce the risk of wildfire: Prohibit smoking outside of designated staging areas at least 20 feet from combustible materials. Soldering and welding is not permitted within 15 feet of dry grass or natural fuels and an extinguisher must be available at all times when soldering, welding or working with motorized machinery. SURFACES AND/OR EARTHWORK Surface and earthwork includes vegetation management, embankment repairs, burrowing rodent control, erosion control, bank hardening, road and boat ramp maintenance, and debris removal. Most surfaces work would require the use of heavy equipment but would not involve use of tools that could spark or start fires, June 2011 Page 3-163

216 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 such as welding equipment or blowtorches. Fuel may be used for equipment and machinery, but would not be stored on site. Open burning is generally prohibited by BAAQMD under Regulation 5. There are 17 exemptions to Regulation 5, which allow fires on permissive burn days at certain times of the year. Burning woody debris at the reservoirs would be permissible under Section (Simon pers. comm. 2007); however, the Santa Clara County Fire Department does not currently allow burning except for agricultural uses because the fire hazard risk is too great (Marbo pers. comm. 2007). The District may consider prescribed burning in the future. The District would obtain all necessary permits and follow all requirements of BAAQMD and the Fire Department established to ensure that risks associated with igniting wildfires are minimized. With implementation of MM Hazards-1, the risk of wildfires from surface and earthwork would be less than significant. MAINTENANCE OF APPURTENANT STRUCTURES Maintenance of appurtenant structures includes repair of inlet/outlet structures and valves, hydraulic systems, fish screens, the outlet pipe and tunnel, concrete structures, etc. Maintenance of dam equipment could require use of tools or equipment such as soldering equipment, welding equipment or blowtorches, which could present a fire threat if the work is performed near dry grass or other natural fuels. MM Hazards-1 discussed above would be implemented at all sites. Other maintenance activities such as concrete repairs and seepage monitoring system installation and repair would not have the potential to ignite wildfires and would not increase fire threats. No fuels for equipment would be stored on site. Work on electrical systems has the potential for electrocution and/or fire. Work would be performed according to Cal/OSHA and District safety regulations to prevent accidental shock or electrical fires for any work on telemetry, SCADA, and other electrical systems. The risk of wildfires from maintenance of appurtenant structures is less than significant with mitigation. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring involve pedestrian and visual surveys and operating valves and/or radial gates. These activities do not have a potential for igniting wildfires. Exploratory work could happen anywhere at the dams, at any time, and would likely involve drilling and excavation, backfilling and compaction for a research need. The construction of temporary access roads could occur as well for exploratory work. Geotechnical investigations are also a form of exploratory work. The potential for these activities to cause fire is low. The risk of wildfires from inspections, monitoring, and exploratory work would be less than significant. June 2011 Page 3-164

217 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 RESERVOIR DEWATERING Reservoir dewatering may be required for activities requiring access to underwater structures that cannot be performed by underwater divers and for outlet maintenance that requires dry conditions. Dewatering would alter downstream flows and habitat but would not create potential for fire or wildfires. Dewatering activities could last for a year depending upon the required repair or type of inspection or exploratory work. The potential for these activities to cause fire is low and no mitigation is necessary. The reservoirs that may potentially be dewatered for dam maintenance can be used as a water source for wildfire suppression. Even when dewatered, each reservoir would have some remaining water that is lower than the outlet of the reservoir. Even when dewatered there would be a source of emergency water for fire fighting, and since no more than one reservoir would be dewatered at a time, there would be other usable reservoirs in the vicinity Impact: Expose Individuals to or Compromise the Environment Through Emission of Hazardous Materials, Substances, or Wastes OVERVIEW Implementation of the DMP requires the use of several substances that are potentially hazardous and could pose a threat to humans and the environment. Substances include herbicides, rodenticides, fuels, lubricants, glues, paints, etc. These materials would be handled according to material safety data sheets (MSDS), Cal/OSHA, District requirements, and other guidance. The District implements several BMPs that pertain to the use of herbicides and rodenticides and the handling of hazardous materials. BMPs would be implemented to minimize the potential for exposure of individuals or the environment to significant effects. SPILL PREVENTION Almost all activities involve the use of vehicles, machinery and common hazardous materials such as fuel, oil, coolants, and paint, which could be introduced to the environment through spills. The District will implement BMPs in all construction and maintenance activities to avoid or minimize the release of common hazardous materials to the environment pursuant to its BMP Handbook. These practices are collectively referred to as Spill Prevention BMPs and are summarized as follows: BMP HM-9: Vehicles would not be washed on-site. BMP HM-10: Equipment and vehicles would be fueled at a proper location. BMP HM-11: Equipment and vehicles would be properly maintained and maintenance would occur at an appropriate location. June 2011 Page 3-165

218 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 BMP HM-12: Hazardous materials would be properly handled and water quality protected by all reasonable means. BMP HM-13: Field personnel will be appropriately trained in spill prevention, hazardous waste control, and clean up for accidental spills. BMP HM-14: A spill kit would always be close proximity of when using hazardous materials. Personnel would know of the locations of spill kits and trained in their use. NATURALLY OCCURRING ASBESTOS Grading and excavation may occur in areas with naturally occurring asbestos. Serpentine or other forms of naturally occurring asbestos may be found within the project area around Almaden Dam, Calero Main Dam, Chesbro Dam, Guadalupe Dam, and Lenihan Dam. Activities that disturb naturally occurring asbestos can cause the fibers to become airborne and pose significant health risks. Disturbance of the asbestos-containing material, particularly over prolonged periods of time and with heavy equipment, could create health hazards to workers and nearby individuals from exposure to airborne asbestos. The BAAQMD regulates construction and grading in areas with naturally occurring asbestos with a rule issued on July 29, 2002 Asbestos Airborne Toxic Control Measure for Construction, Grading, Quarrying, and Surface Mining Operations. The District implements this rule through BMP HM-16, which would require the implementation of BAAQMD dust control measures and notification requirements when working in serpentine soils. MERCURY AND OTHER CONSTITUENTS IN ALLUVIAL SEDIMENT Work within waterways may result in exposure to mercury and other hazardous materials such as PCBs, and organochlorine pesticides (e.g., DDT, chlordane, and dieldrin). Mercury is especially a concern for any work within waterways in the Guadalupe Watershed, which includes areas downstream of Almaden Dam, Guadalupe Dam, and Calero Dam. Workers may be exposed to contaminated sediments and visitors could be exposed to contaminated spoils. The District requires workers to wear personal protective equipment when working in potentially contaminated soils within the Guadalupe Watershed (BMP HM-15). This measure would reduce the potential impact to worker safety, but disturbed or excavated contaminated sediments could still pose a hazard to surrounding land users, which is a potentially significant impact. MM Hazards-2 would require potentially contaminated sediments to be tested and appropriately disposed of if levels exceed 20 parts per million mercury. Caution tape and warning signs would be posted around sediment piles to keep visitors away. MM Hazards-2 would be implemented as necessary for work in the Guadalupe Watershed, to reduce potential impacts to workers, visitors, and the environment from exposure to mercury and other constituents to less than significant levels. June 2011 Page 3-166

219 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Mitigation Measure MM Hazards-2: Dams located within the Guadalupe River watershed shall have any removed sediments and soils tested for mercury prior to disposal. Sediments and soils shall be remediated, capped or disposed in an appropriate facility if levels exceed 20 parts per million mercury. Sediment piles shall be surrounded by caution tape and signed to keep park visitors away from the piles. SURFACES WORK AND/OR EARTHWORK VEGETATION MANAGEMENT Vegetation management is achieved through mechanical and hand removal methods as well as use of herbicides where the public, special status species, and the environment would not be significantly affected. Based on current practices, herbicide active ingredients that may be used in the DMP include: Glyphosate Triclopyr Oryzalin Isoxaben Pendimethalin Clopyralid The range of available herbicide products changes over time. The District continually evaluates these products and may discontinue use of some, and similarly, may adopt others. Before herbicides and rodenticides are registered by the US EPA, they must undergo laboratory testing for short-term (acute) and long-term (chronic) health effects. These tests help scientists determine how chemicals might affect humans, domestic animals, or wildlife in cases of overexposure. Pesticide products used according to label directions are unlikely to cause toxic effects, based on testing (Extoxnet 1996). Risk depends upon hazard (toxicity) and exposure. A measure of hazard to humans is provided by signal words on pesticide labels. The most toxic are labeled DANGER (Class I), followed by WARNING (Class II). The least toxic are labeled CAUTION (Class III). Other potential hazards include carcinogens (cancer-causing substances) or reproductive or developmental toxins. These criteria are not identified on pesticide labels. Risk occurs when humans, wildlife, or other non-target organisms are exposed to or come into contact with hazardous substances. Potential hazards and impacts associated with vegetation management include: Physical harm to people (applicators and personnel or pedestrians and recreationalists) from exposure to toxic chemicals in concentrations high enough to have physical effects; Contamination of the environment such as pollution of soils, groundwater, or surface water; and June 2011 Page 3-167

220 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Negative effects to non-target species from exposure (discussed in Section 3.3 Wildlife). Table lists the potential hazards to humans and the environment from each of the active ingredients and the most common trade names of herbicides that may be used by the District. The District currently implements an herbicide program as part of the SMP. BMPs have been developed for the SMP but would also be applicable to DMP pesticide (i.e., herbicides and rodenticides) use to help minimize the potential risks to people and the environment from herbicide use. Summaries of the BMPs are listed below that describe methods of determining applicability of pesticide use over non-chemical means and reporting pesticide use. The full text of the BMPs can be found in the Mitigation Monitoring and Reporting Program (Appendix V). BMP HM-1: Use of herbicides shall be consistent with approved product specifications. Applications are made under supervision of State Certified applicators. BMP HM-2: An assessment of environmental, economical, and public health aspects of all pesticides alternatives is required prior to pesticide use. BMP HM-3: Pest control methods will be evaluated based on multiple parameters against alternatives. BMP HM-4: Defines appropriate methods for posting and notifying nearby residents and recreationalists of pesticide use. BMP HM-5: Ongoing use of pesticide is subject to recommendations from a licensed Pest Control Advisor and the completion of a Pesticide Use Report. BMP HM-6: Monthly Pesticide Use Reports will be prepared and submitted for the review to the appropriate agencies. June 2011 Page 3-168

221 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Table 3.5-2: Toxicity of District Proposed Herbicides to Humans and Animals and Their Environmental Fate Chemical Toxicity to Humans Toxicity to Animals Environmental Fate Constituent Glyphosate Isoxaben Triclopyr The US EPA classifies Roundup as toxicity class II (moderate toxicity) because it can cause substantial but temporary eye injury and is harmful if swallowed or inhaled. Rodeo, Aquamaster, and Aquaneat are class III (slight toxicity) and harmful if inhaled. The US EPA classifies Gallery DF as category III (Low Toxicity) with a signal word of CAUTION because it causes eye irritation and is harmful if inhaled. The US EPA classifies Garlon 4 as toxicity class III (low toxicity) with a signal word of CAUTION. They classify Garlon 3A as toxicity class I (high toxicity) with a signal word of DANGER because it can cause irreversible eye damage. Glyphosate is practically non-toxic to mammals, birds, amphibians and fish. Glyphosate is slightly toxic to practically non-toxic to aquatic insects. It does not bioaccumulate in these organisms. An extensive review of glyphosate concluded exposure to the chemical does not lead to adverse effects in development or reproduction in mammals. Isoxaben is practically non-toxic to mammals and birds. It was not possible to evaluate the toxicity of isoxaben in fish and aquatic insects because adequate data were not identified. The bioconcentration potential of isoxaben is reportedly low. Triclopyr is slightly toxic to mammals and is practically nontoxic to birds. Triclopyr is practically non-toxic to highly toxic to fish depending on the formulation. Triclopyr amine salt is practically non-toxic to aquatic invertebrates. The half-life of glyphosate in soils ranges from 1 to 174 days with a typical time of 47 days. Microbes break down glyphosate in the environment. Glyphosate is not mobile and has a very low potential to contaminate groundwater. It can move throughout plant tissues, including the roots. A typical half-life for isoxaben in soils is 100 days. Microbes and sunlight break down isoxaben in the environment. Isoxaben s potential to leach to groundwater is low; surface runoff potential is high; and potential for loss on eroded soil is high. Isoxaben has moderate volatility and the potential for loss to the atmosphere is moderate. Plants take up isoxaben primarily through the roots. Isoxaben is translocated to other plant parts. The half-life of triclopyr in soils ranges from 30 to 90 days with a typical time of 46 days. Half-lives are longer in cold, dry conditions. Microbes break triclopyr down. Triclopyr does not bind tightly to soil particles and is highly mobile in the environment, with the potential to contaminate groundwater. Triclopyr absorbs into the roots and leaves of treated plants and is readily translocated through plant parts. June 2011 Page 3-169

222 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Table 3.5-2: Toxicity of District Proposed Herbicides to Humans and Animals and Their Environmental Fate Chemical Toxicity to Humans Toxicity to Animals Environmental Fate Constituent Pendimethalin The US EPA classifies Pendulum AquaCap and Pendulum WDG as category III (Low Toxicity) with a signal word of CAUTION because of moderate eye irritation and harm if swallowed or absorbed through skin. Pendimethalin is considered to be slightly toxic to small mammals by the oral route. Pendimethalin was found to be slightly toxic to birds. Pendimethalin is considered highly toxic to fish based on acute toxicity studies evaluated by US EPA. Technical grade pendimethalin was found to be highly toxic to freshwater invertebrates. A typical half-life for pendimethalin in soils is 90 days. Microbes and sunlight break down pendimethalin in the environment. Pendimethalin s potential to leach to groundwater is low; surface runoff potential is intermediate, and potential for loss on eroded soil is high. Pendimethalin has moderate volatility and the potential for loss to the atmosphere is moderate. Pendimethalin does not bioconcentrate (build up) through the food chain. Pendimethalin is absorbed through the root and shoots and has limited ability to translocate to other plant parts. Oryzalin The US EPA classifies Oryzalin as toxicity class III (low toxicity) with a signal word of CAUTION. Oryzalin is slightly toxic to practically non- toxic to mammals; is slightly to practically non-toxic to birds; is moderately toxic to fish; and is slightly toxic to highly toxic to aquatic insects. The half-life of oryzalin in the field ranges from 20 to 128 days with a typical time of 20 days in soil. Microbes break oryzalin down. Oryzalin is only slightly mobile in the environment but may pose a risk of contaminating groundwater if soils have low organic matter or low clay content and when there is increased rainfall or high water tables. Clopyralid The US EPA classifies Transline as toxicity class III (low toxicity) with a signal word of CAUTION. Clopyralid is practically non-toxic to mammals. Long-term, low-dose (chronic) exposure to the skin or eyes may be more toxic than short-term, high-dose (acute) exposures. Clopyralid does not bioaccumulate in the tissues of exposed land animals. Clopyralid is slightly toxic to birds and practically non-toxic to fish and aquatic insects. The half-life of clopyralid in soils ranges from 14 to 56 days with a typical time of 40 days. Microbes break down clopyralid in soils. Carbon dioxide is the major breakdown product. Small amounts of clopyralid added to leaf materials have no affect on the leaf breakdown. Clopyralid is very stable in compost and can be present in levels that will harm plants. Clopyralid is no longer used for lawn and garden applications because of the potential for contamination of compost through recycling of waste material. Clopyralid is classified as very mobile. However, field studies show that clopyralid has minimal potential to contaminate groundwater through leaching. SOURCE: Extoxnet 1996; US DOE 2000; US EPA 2004; US EPA 2008a; US EPA 20008b; Williams et al June 2011 Page 3-170

223 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Physical Harm to Humans Herbicides applied according to applicable regulations, the label, and the BMPs listed above would minimize potential impacts to human health. Herbicides can be hazardous and have serious health effects to individuals in direct contact; however, the US EPA pursues a rigorous process of evaluation prior to approval of use of a pesticide. Certified applicators are trained to safely handle herbicides per requirements of the US EPA and would supervise pesticide applications (BMP HM-1). BMP HM-12, which requires personnel be trained in the handling and discharge of hazardous materials according to state and federal regulations, would be implemented to minimize potential effects from handling herbicides. Impacts to human health from the application of herbicides would be less than significant. Contamination of the Environment Some of the herbicides used can have a moderate potential to contaminate groundwater and can persist in the soil for as long as a year after application; however, when used according to the label and by a certified applicator, risks to the environment are less than significant. Refer to Section 3.4 Hydrology and Water Quality for additional water quality analysis. While herbicides can persist in soil, most are immobile in soil and do not spread to areas beyond the application site. BMP HM-7, which prohibits the use of pre-emergent herbicides within 72 hours of predicted significant rainfall, would minimize potential impacts to water quality. BMP HM-8 limits the use of aquatic herbicides between July 1 st and October 15 th. Only aquatic herbicides would be applied within 20 feet of any water. BMP HM-7 and BMP HM-8 would reduce potential impacts to the surrounding aquatic environment. Herbicide application areas include the dam faces and areas surrounding blockhouses and other structures. Persistence in soil would not pose a hazardous threat to individuals or the environment because these are mostly filled soils that are stable, not regularly handled, and compacted. Erosion of soils on the dam surface is minimal because the surface is maintained with grasses to prevent/minimize erosion. Potential impacts to wildlife from herbicide use are discussed in Section 3.3 Wildlife. BURROWING RODENT CONTROL Burrowing rodent control methods include handling and application of chemical constituents. Active ingredients that could be used include: Diphacinone Chlorophacinone Zinc phosphide June 2011 Page 3-171

224 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Strychnine Aluminum phosphide Table lists the potential hazards to humans and the environment from each of the active ingredients in District proposed rodenticides and the most common trade names. Potentially significant effects of rodenticides would be similar to those discussed above under herbicide use. Potential hazards could include: Physical harm to humans (applicators and personnel or pedestrians and recreationalists) from exposure to toxic chemicals in concentrations high enough to have physical effects; Contamination of the environment such as degraded groundwater or surface water; and Negative effects to non-target organisms (discussed in Section 3.3 Wildlife). The District currently implements a rodenticide program as part of the SMP to maintain levees (in addition to an herbicide program). Several BMPs developed for the SMP, and described below, would also be applicable for rodenticide use. PHYSICAL HARM TO HUMANS OR CONTAMINATION OF THE ENVIRONMENT BMP HM-1 through BMP HM-6 (described above under Vegetation Management) describe the details of evaluating non-chemical methods of pest control, notifying the public when applying pesticides, applying pesticides under the supervision of a State Certified applicator, and preparing and submitting regular reports when applying rodenticides. There is relatively low risk of poisoning due to ingestion of charcoal or the sodium nitrate found in the fumigant cartridges. The by-products of gas cartridges are sodium nitrate, carbon monoxide, and nitrogen. The sodium nitrate may irritate humans, but it is produced underground so it shouldn t disturb the applicators. Carbon monoxide and nitrogen easily dissipate into the environment. Rodents killed by carbon monoxide pose no threat to scavengers. Accidental releases or spills of rodenticides could expose visitors or District personnel to toxic substances and lead to serious health effects to individuals in direct contact. The spill prevention BMPs discussed in the Overview would minimize risks associated with accidental spills or releases of hazardous materials into the environment. Impacts to humans from the use of rodenticides would be less than significant. If shooting is used as a method to control ground squirrels, great care must be given to protect people and pets that may be in the area. Acrylic bullets would June 2011 Page 3-172

225 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 be used to eliminate the possibility of a bullet richoting away from the attended target. Acrylic bullets would also avoid any impact associated with the use of lead or other metals for bullets. To ensure that any danger associated with shooting is minimized to the greatest extent feasible, the District would implement MM Hazards-3, which requires the closure of all adjacent trails to the public during times that shooting will occur. Kill traps may be used as a method to control burrowing rodents. Use of these traps has a possibility to injure trail users or pets if a person or animal touches or handles the trap. To ensure that danger associated with kill traps is minimized, kill traps will only be used underground inside rodent tunnels and the District would implement MM Hazards-4, which would require that kill traps be located at least 200 feet from a public trail. Mitigation Measures MM Hazards-3: If shooting is used as a method to control ground squirrels, any trail adjacent to the area of control will be closed to public use for the duration of activity. MM Hazards-4: If kill traps are used as a method to control burrowing rodents they shall be located at least 200 feet from a public trail. June 2011 Page 3-173

226 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Table 3.5-4: Toxicity of District Proposed Rodenticides to Humans and Animals and Their Environmental Fate Rodenticide Toxicity to Humans Toxicity to Animals Environmental Fate Diphacinone Diphacinone is a highly toxic compound in US EPA toxicity class I. All formulations of diphacinone are Restricted Use Pesticides (RUPs). RUPs may be purchased and used only by certified applicators. The Signal Word required on products containing diphacinone varies, depending on the type of formulation: DANGER applies to the technical material, WARNING to concentrate formulations, and CAUTION to bait formulations. Diphacinone is slightly toxic to birds but is moderately toxic to fish species and aquatic invertebrates. Documented effects on amphibians have not been found but it is very likely diphacinone could range in toxicity from acutely toxic to highly toxic to amphibians. Studies with cattle indicate a high degree of tolerance for the compound, hence its use against vampire bats preying on cattle in Latin America. Chlorophacinone Chlorophacinone is placed in toxicity class I by the US EPA for oral and dermal acute toxicity. Zinc phosphide Zinc phosphide is a RUP 24 because of its hazard to non-target species and its acute oral toxicity. Some formulations are classified as highly toxic and require the Signal Word DANGER - POISON on the label. Others are either moderately toxic or only slightly toxic, and thus require the Signal Words WARNING or CAUTION, respectively. Chlorophacinone is of low toxicity to birds. Chlorophacinone could be hazardous to other small mammals if used indiscriminately. Zinc phosphide is highly toxic to birds. Zinc phosphide is highly toxic to freshwater fish. Zinc phosphide is also toxic to non-target mammals when ingested. Secondary toxicity to mammalian predators (animals eating other animals that had been exposed to the compound) from zinc phosphide is rather low, because the compound does not significantly accumulate in the muscles of target species. Some of the toxic effects to predators have been due to the ingestion of zinc phosphide in the digestive tract of the target organism. Diphacinone has a low potential to leach in soil and is rapidly decomposed in water by sunlight. No data are currently available for its breakdown in vegetation. Chlorophacinone is moderately susceptible to photodegradation on soil (half-life of 4 days) and is moderately degradable in a sandy clay loam soil under aerobic conditions (half-lives of days). Chlorophacinone is expected to be very immobile soil and volatilizes slowly from both water and soil. Zinc phosphide may be applied as an active ingredient in either bait or a dust. Under average conditions, toxic activity persists for approximately 2 weeks. Soil acidity and moisture tend to accelerate the breakdown of the compound. Phosphine gas may be liberated as a result of this process. 24 Restricted Use Pesticide June 2011 Page 3-174

227 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 Table 3.5-4: Toxicity of District Proposed Rodenticides to Humans and Animals and Their Environmental Fate Rodenticide Toxicity to Humans Toxicity to Animals Environmental Fate Strychnine Strychnine has been placed in toxicity class I by the US EPA, indicating a high degree of acute toxicity, for oral and ocular effects. Inhalation toxicity is also presumed to be high. Aluminum phosphide Aluminum phosphide is a RUP so it may be purchased and used only by certified applicators. It is in US EPA Toxicity Class I and products containing it must bear the signal word DANGER. SOURCE: Extoxnet 1996; US EPA 1996 Acute toxicity of strychnine to birds is assumed to be very high. Subacute dietary data indicate that strychnine ranges from slightly to highly toxic to avian species. Strychnine may pose a threat to birds that may be subject to repeated or continuous exposure from spills. Mammalian studies indicate that strychnine is very highly toxic to small mammals on both an acute oral basis and dietary basis. The signs of toxicity, including death, occur within one hour. Acute freshwater fish data reveal that strychnine ranges from moderately to highly toxic to freshwater fish and aquatic invertebrates. The precise oral or inhalation median lethal doses for aluminum phosphide or phosphine in birds are not known. Fortunately, such exposure is not very likely, as phosphine is rapidly dissipated in open air. Phosphide is very highly toxic to fish. No data were available regarding the specific toxicity of aluminum phosphide or of phosphine to other fish or aquatic species, but due to the mechanism of action it is likely that it will be very highly toxic to them as well. Such exposure is unlikely; aluminum phosphide will rapidly react to form phosphine gas, which is somewhat soluble in water, but will mainly bubble up into the air. When released into the soil, strychnine has the potential to photolyze (break down with light) on soil surfaces. Volatilization and chemical hydrolysis are not expected. When released into water, this material has the potential to photolyze. Volatilization, chemical hydrolysis and bioaccumulation in aquatic organisms are not expected. When released into the atmosphere, this material has the potential to be removed by direct photolysis or dry deposition. Aluminum phosphide will break down spontaneously in the presence of water to form a gaseous product, and so it is non-persistent and non-mobile in the soil environment, and poses no risk to groundwater. June 2011 Page 3-175

228 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 ROAD AND BOAT RAMP MAINTENANCE Road maintenance would include filling erosion rills, grading and laying new aggregate base or gravel, and stabilization. Hazards associated with roadwork and boat ramp maintenance include the potential for contamination of the environment from chemical spills and exposure of workers to naturally occurring asbestos. With the Spill Prevention BMPs discussed above (BMPs HM-9 through 14) and the compliance with regulations regarding naturally occurring asbestos (BMP HM-16) potential impacts from boat and ramp maintenance work would be less than significant. EROSION CONTROL, BANK STABILIZATION AND EMBANKMENT REPAIR Erosion control, bank stabilization, and embankment repair would require the use of some heavy equipment such as bulldozers and loaders. Heavy equipment has the potential for leaks or spills of fuels and lubricants that could contaminate the environment. However, the District will implement Spill Prevention BMPs (BMPs HM-9 through 14) to minimize potential for leaks or spills of hazardous materials. Work in waterways also has the potential to expose mercury or other constituents in alluvial sediment. Erosion control and bank stabilization in the Guadalupe River watershed would require MM Hazards-2 as discussed above to reduce the potentially significant impact associated with expose of mercury. With the implementation of the mitigation measure and District BMPs, potential impacts from erosion control and bank stabilization would be less than significant. TRASH AND DEBRIS REMOVAL Debris removal includes hauling waste that can range from paper trash to large appliances that have been illegally dumped at the dams. Debris removal also includes removal of woody debris that has accumulated along the upstream dam face. Removal of debris would not generate any hazards or cause a hazard to the environment. Potential hazards associated with trash and debris removal would involve potential hazard to workers from exposure to illegally dumped hazardous wastes. Any hazardous debris such as old oil filters or household hazardous wastes would be disposed of at an appropriate landfill that accepts such waste and this impact is considered less than significant. Debris removal would have an overall positive effect on the environment. MAINTENANCE OF APPURTENANT STRUCTURES Maintenance of appurtenant structures includes maintenance of equipment such as the hydraulic systems, inlet and outlet structures, inlet/outlet valves, outlet pipe and tunnel, concrete structures, fish screens, etc. Work on the upstream structures (structures on the reservoir side) can occur underwater using divers or can occur when the reservoir level is low enough to permit access to the inlet structures. Maintenance on the downstream structures and outlet pipe/tunnels can typically June 2011 Page 3-176

229 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 occur with the inlet/outlet valve closed. Maintenance can vary from repairing or cleaning structures to replacing parts. Maintenance also includes clearing accumulated sediment from the inlet structure and hydraulic system area by bringing the sediment to the surface for disposal. Potential hazardous impacts to humans or the environment that can result from maintenance of appurtenant structures include potential hazard to workers, visitors and the environment from exposure to spills of fuels and other potentially hazardous substances such as epoxies, glues, paints, cement chemicals, etc.; potential exposure of workers and park visitors to and potential release into the environment of natural or commercial asbestos; and potential exposure of workers, and visitors, and potential release into the environment of mercury. Accidental spills, exposure to naturally occurring asbestos, and exposure to mercury in sediments of the Guadalupe watershed are discussed above. All appropriate BMPs would be implemented for maintenance of appurtenant structures, and MM Hazards-2 would be required for any work in a waterway of the Guadalupe watershed. Spilling of hydraulic fluid on and in the reservoir is possible during inlet valve and hydraulic system maintenance. Spills of hydraulic fluid are cleaned up immediately using absorbent diapers and booms on the reservoir surface. A spill prevention and clean up kit is available at all times when maintenance or inspection of the inlet/outlet valves occurs, as described in BMP HM-14. The District has a HMBP for each dam facility. Small amounts of hazardous materials may be handled on-site, such as generator fuel and hydraulic fluid. The HMBP includes a list of all the hazardous materials on-site, a description and location of the containment vessels, and a visual inspection protocol. The HMBP also includes an emergency response plan and contingency plan to handle any accidental spills or release of hazardous materials. Implementation of the plan and spill prevention BMPs minimizes the potential for a hazardous spill. Naturally occurring asbestos would not likely be encountered during maintenance of appurtenant structures since work would most often occur on and around existing structures and on the dam face. The dam face is comprised of fill material. Most naturally occurring asbestos would occur in surrounding areas such as downstream of the dam or on slopes to the sides surrounding the dam. Equipment and structures are not typically located in these areas. Potential impacts to workers and the environment from naturally occurring asbestos disturbed during maintenance of appurtenant structures would not occur. Demolition of old structures, such as blockhouses (were demolition to occur), could disperse commercially used asbestos into the air, which is a potentially significant impact. Asbestos may or may not be present in blockhouses, depending on the structure and the time period that they were built. Because asbestos has been used in many structural applications, BAAQMD s Regulation requires that for every demolition or for every renovation involving the removal of 100 square feet/linear feet or greater of Regulated Asbestos Containing Material (RACM), a notification must be made to BAAQMD at least 10 working days prior to commencement of demolition. Regulation requires that a survey be performed prior to demolition to determine the presence of RACM. The person who performs the survey must be Cal/OSHA certified and must have taken and passed June 2011 Page 3-177

230 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 an US EPA approved building course. To determine the presence of asbestos, a sample must be taken to a laboratory and tested using polarized light microscopy as the testing methodology. The California State Contractors Board requires that a contractor have a valid, current contractor s license and certificate for asbestos abatement work. The District would follow all regulations regarding asbestos surveying and removal. MM Hazards-5, which requires the District to acquire all necessary permits and perform required inspections prior to the demolition of any structures, would be implemented to ensure compliance with BAAQMD regulations. Impacts would be less than significant with proper identification and removal of asbestos prior to demolition. MITIGATION MEASURE MM Hazards-5: Prior to demolition of any structure at the dam facilities, such as blockhouses, pump houses, etc., the District will follow all BAAQMD regulations pertaining to demolition of structures. The District shall have an asbestos survey performed by a surveyor certified for asbestos inspection by the California State Contractors Board and provide all required notifications and obtain necessary permits from BAAQMD prior to removal. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring generally involve visual surveys of the dam facilities and surrounding equipment by District and agency personnel. Inspections can also involve exercising radial gates and/or inlet/outlet valves. Exploratory field investigations include backhoe trenches and borings, needed to either understand geologic processes acting on dams or to monitor such processes and plan to respond to them, if needed. Excavation, backfilling, compaction, and temporary access roads are all involved in exploratory work. Exploratory work can also include the use of barges for underwater drilling into the dams. Potential hazardous impacts to humans or the environment that can result from inspections, monitoring, and exploratory work includes potential hazard to workers and the environment from exposure to fuels, and potential exposure of workers to and potential release into the environment of natural or commercial asbestos. Accidental spills, exposure to naturally occurring asbestos, and exposure to mercury in sediments of the Guadalupe watershed are discussed above. All appropriate BMPs would be implemented for maintenance of appurtenant structures, and MM Hazards-2 would be required for any work in a waterway of the Guadalupe watershed. Exercising of the radial gates would have the potential for release of lubricating oil. The District would always carry spill clean-up kits when exercising inlet valves, which require use of the hydraulic fluid (BMP HM-14). Any hydraulic fluid spills are cleaned up immediately according to the HMBP. Exploratory work has the potential to expose workers, visitors, and the environment to many of the same hazards previously discussed (such as hazards from chemicals, hazards from asbestos, hazards from mercury, etc.) from the operation of heavy machinery and surface disturbance. BMP HM-15 would ensure worker safety when June 2011 Page 3-178

231 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 working in areas with potentially elevated contaminant concentrations by requiring the use of personal protective equipment according to Cal/OSHA regulations. MM Hazards-2 would require mercury testing for soils removed from dams within the Guadalupe River watershed prior to disposal. The implementation of this mitigation measure would reduce potential impacts from contamination to the environment to a less than significant level. RESERVOIR DEWATERING Reservoir dewatering would not result in the emission of any hazardous materials. Reservoir dewatering allows workers to access structures in need of the preventative or corrective maintenance. Impacts from maintenance activities have been previously addressed above. Dewatering may require the use of a generator to provide bypass flows. The District will implement Spill Prevention BMPs (BMPs HM-9 through 14) to minimize potential for leaks or spills of hazardous materials whenever a generator is used Impact: Emit Hazardous Emissions or Handle Hazardous or Acutely Hazardous Materials, Substances, or Waste Within ¼ Mile of an Existing or Proposed School None of the dam sites are within a quarter mile of an existing or proposed school. There would be no impact from hazardous material associated with the DMP on nearby schools Impact: Create a Significant Hazard to the Public or the Environment From Existing Hazardous Material Contamination On Site or Nearby None of the dams are listed as sites with known toxic or hazardous materials. As discussed above, the Guadalupe River watershed is known to have mercury contamination from historical mining operations and MM Hazards-2 is incorporated to properly dispose of mercury contaminated soil. Mercury would only be located in sediment within Guadalupe River watershed waterways. The dams were constructed with clean imported fill and adjacent hillsides were never used for industrial or agricultural purposes that would suggest chemical contamination Impact: Result in a Substantial Safety Hazard for People Residing or Working in the Project Area Located Within Two Miles of an Airport, or to Aircraft Utilizing the Airport None of the dams are located within two miles of an airport. Coyote, Uvas and Chesbro dams are at least three miles from the San Martin airport. Maintenance activities would have no impact to aircraft, and the proximity of dam sites to airports does not represent a hazard to workers from aircraft. June 2011 Page 3-179

232 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER MITIGATION MEASURES Mitigation Measures MM Hazards-1: For all work elements of the DMP, the following fire prevention measures will be implemented to reduce the risk of wildfire: Prohibit smoking outside of designated staging areas at least 20 feet from combustible materials. Soldering and welding is not permitted within 15 feet of dry grass or natural fuels and an extinguisher must be available at all times when soldering, welding or working with motorized machinery. MM Hazards-2: Dams located within the Guadalupe River watershed shall have any removed sediments and soils tested for mercury prior to disposal. Sediments and soils shall be remediated, capped or disposed in appropriate facility if levels exceed 20 ppm mercury. Sediment piles should be surrounded by caution tape and signed to keep park visitors away from the piles. MM Hazards-3: If shooting is used as a method to control ground squirrels, any trail adjacent to the area of control will be closed to public use for the duration of activity. MM Hazards-4: If kill traps are used as a method to control burrowing rodents they shall be located at least 200 feet from a public trail. MM Hazards-5: Prior to demolition of any structure at the dam facilities, such as blockhouses, pump houses, etc., the District will follow all BAAQMD regulations pertaining to demolition of structures. The District shall have an asbestos survey performed by a surveyor certified for asbestos inspection by the California State Contractors Board and provided all required notifications and obtain necessary permits from BAAQMD prior to removal. RESIDUAL IMPACTS AFTER MITIGATION All impacts would be reduced to less than significant levels with implementation of the mitigation described above. BEST MANAGEMENT PRACTICES (SEE THE MITIGATION MONITORING AND REPORTING PROGRAM (APPENDIX V) FOR COMPLETE TEXT OF BMPS) HM-1: Comply with All Pesticide Application Restrictions HM-2: Use Appropriate Type(s) of Pest Control HM-3: Consult the Pest Control Advisor for Alternatives Evaluation and Approval of Pest Control HM-4: Follow All Posting and Notification Requirements for Pesticide Use HM-5: Comply with All Pesticide Usage Requirements HM-6: Coordinate Pesticide Use Reporting with the Vegetation Management Unit Manager June 2011 Page 3-180

233 Section 3.5 Hazards, Hazardous Materials, and Human Health and Safety CHAPTER 3 HM-7: Comply with Restrictions on Herbicide Use in Upland Areas HM-8: Comply with Restrictions on Herbicide Use in Aquatic Areas HM-9: Clean Vehicles and Equipment HM-10: Assure Proper Vehicle and Equipment Fueling HM-11: Assure Proper Vehicle and Equipment Maintenance HM-12: Assure Proper Hazardous Materials Management HM-13: Prevent Spills HM-14: Know the Spill Kit Location HM-15: Soils with High Mercury Levels HM-16: Comply with BAAQMD Regulations for Naturally Occurring Asbestos June 2011 Page 3-181

234 Section 3.6 Cultural Resources CHAPTER CULTURAL RESOURCES ENVIRONMENTAL SETTING Overview This section of the document describes the cultural (prehistoric and historic) setting of the project area, potential effects of the proposed project, and protocols for addressing cultural resources. The majority of DMP activities have little or no potential for disturbing cultural resources. Only activities that involve native soil disturbance, extensive excavation, and/or structural or material changes to the dams have the potential to affect cultural resources. Relevant environmental, historical, ethnographic, and archaeological data are discussed as a basis for understanding the types and potential significance of cultural resources that might be located in the project area. A records search for a one-quarter-mile radius around the APE for each of the 14 dams was conducted at the Northwest Information Center, Sonoma State University, in Rohnert Park. The full records search results are found in Cultural Resources Investigations for the Dam Maintenance Program, prepared by Far Western Anthropological Group, Inc. (Byrd and Berg 2006). An historic evaluation was also conducted to determine the potential significance and eligibility of the dams and related structures for inclusion in the National Register of Historic Places (NRHP). Historical significance evaluations are included in the report Santa Clara Valley District Dams, prepared by JRP Historical Consulting, Inc. (Herbert et al. 2006) Cultural and Historic Resources PREHISTORIC BACKGROUND GEOLOGICAL AND GEOGRAPHIC CONDITIONS AND THE EARLIEST ARCHAEOLOGY The Santa Clara Valley landscape has changed significantly during the 15,000 years since humans first occupied the region. Large drainages once flowed from the Santa Clara Valley out through the Golden Gate during the late Pleistocene, but were inundated by rising ocean waters when continental glaciers began to melt with the onset of the Holocene epoch. Sea level rise was rapid between 12,000 and 6,000 years ago (roughly 0.8 inches per year), resulting in the development of the San Francisco Bay estuary. For the last 6,000 years, the rate of glacier melting slowed down, and Holocene terrestrial sedimentation outpaced the rate of sea level rise, resulting in the extensive tidal marshes and mudflats we see today at the south end of the bay (Rosenthal and Meyer 2004). Floodplains and alluvial fans of the Santa Clara Valley experienced repeated cycles of deposition, erosion, and stability; processes that have strongly June 2011 Page 3-182

235 Section 3.6 Cultural Resources CHAPTER 3 influenced the condition of the local archaeological record. Geo-archaeological studies of the Santa Clara Valley-San Francisco Bay Area indicate that a large portion of the early and middle Holocene archaeological record may lie deeply buried under more recent alluvial and floodplain deposits that have filled many low-lying settings in the region. More than 60 percent of the recorded archaeological sites within certain portions of the Santa Clara Valley occur in buried contexts. Most of these sites are associated with buried soils located near major drainages, such as the Guadalupe River and Coyote Creek (Allen et al. 1999; Rosenthal and Meyer 2004). As a result of these relationships, prehistoric archaeological materials older than 4,500 years are relatively rare in the local area. The following discussion provides a brief review of the local culture history, dividing the archaeological record into five generalized time periods derived from the work of Fredrickson (1974) and Meyer and Rosenthal (1997). This analysis is based on the archaeological report prepared for the proposed project area (Byrd and Berg 2006). Lower Archaic Period (10,000-6,000 years ago) Archaeological components dating to the Lower Archaic are essentially absent from the shores of San Francisco Bay, but have been discovered at the south and western edges of the Santa Clara Valley (Fitzgerald and Jones 1999; Hildebrandt 1983; Hildebrandt 1997). Artifact assemblages include handstones, millingslabs and cobble-core tools. Early inhabitants of this time period likely hunted small game and gathered a variety of plant foods. The populations were mobile and their food systems focused on acquisition of low-bulk resources because of a lack of storage capabilities (Hildebrandt and McGuire 2002; McGuire and Hildebrandt 1994). Connections between the Santa Clara Valley and the outer coast during this early period of prehistory are also documented by the presence of Olivella spire-lopped beads known to originate at the outer coast but found in the Valley (Fitzgerald et al. 2005; Hildebrandt 1983). Initial Middle Archaic Period (6,000-4,500 years ago) Archaeological materials dating to the initial Middle Archaic interval are also quite rare in the Santa Clara Valley area. A few isolated human burials have been recovered from this era in the Sunnyvale area (Allen et al. 1999; Milliken et al. 2006). Terminal Middle Archaic Period (4,500-2,500 years ago) Initial use of shell mound sites (prehistoric refuse heaps consisting of the shells of edible mollusks) along San Francisco Bay appear to have begun during the Terminal Middle Archaic period. Many sites dating to this interval appear to represent the first evidence for sedentary or semi-sedentary settlement organization in the region. Mammalian June 2011 Page 3-183

236 Section 3.6 Cultural Resources CHAPTER 3 remains show high relative frequencies of elk, deer, and canids, and lesser amounts of sea otter (Broughton 1994; Simons 1992). Despite the presence of mortars and pestles, Gerow and Force (1968) argue that acorns were not yet a major component of the diet (Meyer and Rosenthal 1997; Wohlgemuth 1996; Wohlgemuth 2004). Upper Archaic Period (2,500-1,000 years ago) Upper Archaic sites are found in a number of locations in the Santa Clara Valley region and are typically composed of well-developed midden deposits containing hundreds of flexed burials and residential features. Populations in the region were becoming more sedentary. Obsidian artifacts reach peak proportions during the Upper Archaic period, including items originating from the eastern Sierra and Napa (Hylkema 2002). Artifacts found during from this period include well-developed bone tools, numerous saucer and saddle-shaped Olivella beads, abalone ornaments and pendants, and both shaped and unshaped mortars and pestles. The inhabitant diets during the Upper Archaic included acorns and other large nuts and seeds (as evidenced by mortar and pestles). Shellfish and terrestrial mammals were also important dietary elements. Fishing may also have been important, and included a wide range of taxa such as salmon, sturgeon, and bat ray. More intensified fishing is also indicated by advancements in harvest technology, most notably harpoons. Emergent Period (1,000 years ago to pre-european) The remaining archaeological complex in the region (known as the Augustine Pattern) is marked by the first appearance of arrow-sized projectile points, beautiful trimmed show mortars, flanged pestles, flanged steatite pipes, and chevron-designed bird bone tubes. Several important settlement pattern shifts occur in certain parts of the region, but the scale of these changes is difficult to determine because very few areas have been systematically studied. ETHNOGRAPHIC BACKGROUND The Santa Clara Valley falls within the territory for Ohlone-speaking Native Americans (Levy 1978). The Ohlone (also referred to as Costanoan) language group is either considered a distinct language family, comprised of eight languages (Levy 1978) or falling within a language family that included the Bay Miwok (Milliken 1995; Shipley 1978). The territorial structure of the region included tribelets (Bean 1978; Kroeber 1925). Tribelets were typically comprised of one village or more and a surrounding territory (the foraging area of a group). Population size of an Ohlone tribelet ranged from people. The boundaries of tribelet territories defined the range of resources that could be exploited during the annual cycle, and have been reconstructed in this region as averaging 12 miles in diameter (Milliken 1995). Population densities are estimated to have been at least eight people per square June 2011 Page 3-184

237 Section 3.6 Cultural Resources CHAPTER 3 mile. These territories appear to have been well defined. Transgressions by members of neighboring tribelets were the source of considerable friction and often deadly conflict. Hunting and gathering focused on various nuts, seed, roots, and berries; large and small mammals; fish; waterfowl and other birds; and for near-shore and bay inhabitants, a range of marine resources. Baskets of varied design were used in all stages of plant gathering and processing, while the bow and arrow was used as the primary hunting weapon. Watercrafts were used and consisted of tule balsa with double-bladed paddles. There were no political entities larger than the tribelet. Regional interaction was undoubtedly highly varied, subject to inherent instability, and required considerable attention and persistent negotiation. Inter-tribelet warfare was widespread and territorial transgressions were dealt with severely (including displaying the heads of the vanquished on pikes within villages). Regional trade, however, was pervasive and included dietary staples (such as shellfish, fish, pine nuts, and salt) as well as raw materials and finished products, such as shell beads. Trade also crosscut linguistic borders. According to Milliken s (1995) ethno-historic research, it appears that few of these settlements were occupied on a year-round basis, and few of the bayshore mounds were actually occupied when the Spanish first arrived in the region. Based on these findings, it appears that the ethno-historic record is consistent with the late prehistoric archaeological record, and may differ significantly from the more centralized subsistence-settlement regime that was present during the Upper Archaic Period. HISTORIC BACKGROUND EUROPEAN PERIOD Sixteenth century sea-going European explorers were the first to reach the coastline of the San Francisco Bay Area. It was not until the late eighteenth century that explorers intruded into the Santa Clara Valley area as an initial step toward founding missions, presidios, and pueblos. The 1776 expedition led by Juan Bautista de Anza and Pedro Font traversed the northern portion of the Santa Clara Valley and made observations regarding the natural setting and Native American villages in preparation for the establishment of new Spanish outposts (Bolton 1927; 1930). They established the Presidio and Mission of San Francisco later that year. José Joaquin Moraga and Fray Tomas de la Pena followed and established the Mission Santa Clara de Asis on the west bank of the Guadalupe River in 1777, at the northeastern edge of Tamien tribal territory. The river soon flooded out this location, and the mission was relocated twice to higher ground. The establishment of the missions, pueblos, and presidios marked the onset of active coercement and resettlement of Native Americans into the mission feudal system. Local populations began to decline, due in large part to June 2011 Page 3-185

238 Section 3.6 Cultural Resources CHAPTER 3 introduced diseases. Environmental changes were also a significant factor, as the Spanish altered the landscape into one more suitable for livestock grazing and farming. Traditional resources were increasingly curtailed; not only was wild game forced to compete with the great Spanish cattle herds, but the damage done by overgrazing had severe consequences for vegetal and freshwater resources (Milliken 1995). Local streams and creeks near the mission were diverted and claimed for the farms and orchards. Eventually, population decline and landscape alteration forced people into the mission system, and the survivors learned to adapt to the new economy. By 1795, all of the Tamien villages had been abandoned and their inhabitants had been baptized (Milliken 1995). AMERICAN PERIOD The outbreak of civil unrest in Mexico beginning in 1810 caused disruptions to Spain s fledgling colony. Shipping traffic from Mexico was erratic, encouraging illegal trading with foreign ships for needed supplies. When Mexican Independence was achieved in 1822, control of California passed from Spain to Mexico. The new Mexican government instituted many changes to develop their new colony. Foreign trade was legalized, opening up a lucrative hide and tallow market, which drove California s economy during this period. Secularization of the missions in 1834 redistributed some of the church s vast land holdings to California citizens, and large ranchos were established in the late 1820s and 1830s to support the vast cattle herds. In the Santa Clara Valley, 38 land grants were issued between 1833 and 1845 (Gilreath and Detlefs 2002). Each rancho was typically self-supporting, with cultivated fields, vineyards, and grazing land, as well as tanneries, grist mills, and other small-scale industrial endeavors. The Mexican government also relaxed immigration rules in 1828, which allowed more foreigners, including Americans, to settle in California. Their numbers increased following the first overland migration to California in 1841, and by 1845, some 900 Americans lived in the pueblo. The increasing hordes of American immigrants alarmed the Mexican government, and tensions escalated into the Mexican-American War in In 1848, the United States acquired California under the Treaty of Guadalupe Hidalgo. The Gold Rush began soon after this event, bringing even more people to California. Many of these would-be miners stayed in California and attempted to settle in the fertile valleys as farmers and ranchers. The Gold Rush also sparked interest in the cinnabar deposits south of San Jose in the Santa Cruz Mountains. These deposits, the New Almaden Mines, contain mercury, which was necessary to help separate gold from ore. Although mining had begun in 1845 during the Mexican era, they were intensively worked following the discovery of gold, and were the largest mercury mines in North America. The great influx of Gold Rush-era immigrants created new economic opportunities for the farmers and ranchers of the Santa Clara Valley. Livestock continued to be the greatest market, only the focus changed from hides and tallow to meat in order to feed the mining camps. The fertile valley was also June 2011 Page 3-186

239 Section 3.6 Cultural Resources CHAPTER 3 favorable for wheat crops, and Santa Clara County produced 30 percent of California s total wheat crop by 1854 (Gilreath and Detlefs 2002). Other grain crops such as barley and oats were also important crops in Santa Clara Valley (Gilreath and Detlefs 2002), as well as hay for cattle feed. After about 1875, horticulture became the favored pursuit, with fruit production gaining in prominence. The best known of these crops was the prune, and by 1932, Santa Clara Valley supplied one-third of the global market. Horticulture continued to drive the County s economy until the advent of the high-technology industry during the postwar era. The City of San Jose developed rapidly in the mid-nineteenth century, especially once the Guadalupe River had been sufficiently channelized to reduce the threat of flooding. A railroad extended to San Francisco by 1864, followed by the transcontinental railroad in 1869, which opened up new markets. These expanding markets stimulated new industries. Fruit canning dominated the local economy by the beginning of the twentieth century (Gilreath and Detlefs 2002). The Del Monte cannery in Midtown was the largest employer in the city for many years. Other industries flourished which supported the fruit industry, such as box, basket, ice, and can factories and machinery shops. One such business, Food Machinery Corporation, was founded in It later received the city s first federal defense contract to build armored vehicles during World War II, and became United Defense, which currently employs some 100,000 people across the country. By the 1960s, defense and electronic industries were forefront in San Jose. Early businesses that established plants in San Jose were General Electric and IBM (Gilreath and Detlefs 2002). In the 1950s, San Jose experienced an even larger growth surge. In 1950, the population was 95,000 and the city covered 17 square miles. By 1969, the city was home to 495,000 residents and encompassed 136 square miles. The electronics boom of the 1980s transformed Santa Clara Valley into Silicon Valley, home to 1.7 million in HISTORY OF SANTA CLARA VALLEY WATER DISTRICT Overview At the turn of the twentieth century, the Santa Clara Valley remained a predominantly agricultural area with a small urban center concentrated in San Jose. Groundwater levels at this time were sufficiently high that wells often flowed under artesian pressure. A combination of modern pumps allowing increased pumping and drought resulted in a substantial drop in groundwater levels by The valley s farmers had approximately 67 percent of the area under irrigation by 1920, and the population of its urban centers was on the rise. The groundwater table had dropped 50 feet in four years, increasing pumping costs and causing the ground to subside (Tibbetts 1934; ASCE 1977). These factors led Valley leaders and local engineers to seek a means to replenish the lowering groundwater table. June 2011 Page 3-187

240 Section 3.6 Cultural Resources CHAPTER 3 Dam Construction During the 1920s, hydraulic engineer Fred H. Tibbetts and his partner Stephen Kieffer undertook a study of the valley s water problems and proposed a system of dams and conservation facilities to aid in recharging the valley s groundwater. They called for establishment of a water conservation district, with reservoirs and flood control channels to retain the highly variable flows in the streams for the purpose of groundwater recharge. The voters first defeated establishment of a water conservation district in 1927 and 1928, but when water levels in local wells fell below 100 feet in 1929, the voters approved the measure and established the Santa Clara Valley Water Conservation District in 1929 (SCVWCD) (ASCE 1977; Tibbetts 1936). The District s leaders had settled on construction of six major dams, along with streambed improvements and small, inexpensive in-stream structures to enhance groundwater recharge. The original dams built to enhance groundwater recharge were: Calero Dam (includes the Main Dam and the Auxiliary Dam, but not Fellows Dike) Almaden Dam Guadalupe Dam Vasona Dam Stevens Creek Dam These dams were completed by The seventh, Coyote Dam, was finished in Coyote Percolation Ponds Dam was finished in The dams began to store water and improve groundwater conditions. Almaden Reservoir and Calero Reservoir were connected by the Almaden-Calero Canal, which shunted water from the relatively wet Almaden basin into the larger storage capacity afforded by Calero Reservoir (ASCE 1977). Fellows Dike was completed in 1936 at Calero Reservoir to protect the adjacent ranch property from flooding. Fellows Dike was built after the construction of the Calero Dam and was not part of the original design for groundwater recharge. Table lists the individual dams, their date of construction, principal engineer, and the construction company. June 2011 Page 3-188

241 Section 3.6 Cultural Resources CHAPTER 3 Table 3.6-1: Construction Date, Engineers, and Construction Companies for Historic Dams Dam Dates of Construction Engineer/Construction Company Almaden Dam 1935 Fred Tibbetts/F.O. Bohnett & D. McDonald Calero (Main and Auxiliary Dams) 1935 Fred Tibbetts/F.O. Bohnett & D. McDonald Coyote Dam Fred Tibbetts/Macco Construction Co. Coyote Percolation Ponds Dam 1932 Fred Tibbetts/Macco Construction Co. Guadalupe Dam 1935 T.D. Sawyer/Teichert & Sons, Inc. Stevens Creek Dam 1935 Fred Tibbetts/F.O. Bohnett & D. McDonald Vasona Dam 1935 Fred Tibbetts/Carl Swenson Co. SOURCE: ASCE 1977 Dam Construction Groundwater levels reached 131 feet below the surface in 1937, whereas twenty years earlier it was only 56 feet below surface. By 1943, the groundwater level in the Valley returned to the average level of the 1920s (50 feet); however, increased urbanization, wartime industrial requirements, and year-round irrigation began to again adversely affect the water table. The SCVWCD decided to build two additional dams. Lexington Reservoir would store 20,210 acre-feet and Anderson Reservoir would store 91,280 acre-feet (ASCE 1977). The SCVWCD completed Lexington Dam (later renamed Lenihan Dam) in 1952, and Anderson Dam in Voters south of San Jose established the South Santa Clara Valley Water Conservation District in 1938, following the success of the SCVWCD reservoir system. The new district covered 34,900 acres with the goal of preventing land subsidence, increasing groundwater yields, and reducing flood flows of the creeks in south Santa Clara County that flowed to the Pajaro River. The new District, which was managed by elected citizens and members of the Board of Supervisors, began constructing percolation facilities on area creeks. The South Santa Clara Valley Water Conservation District established plans for two dams and reservoirs on the Llagas and Uvas creeks in the 1950s (California History Center 1981). These dams include Uvas Dam and Chesbro Dam constructed in 1957 and 1955, respectively. Dam Construction Most of the smaller local water conservation districts had merged with SCVWCD by The people served by the South Santa Clara Valley Water Conservation District voted to remain independent. The board of directors changed the South Santa Clara Valley Water Conservation District s name to the Gavilan Water Conservation District. June 2011 Page 3-189

242 Section 3.6 Cultural Resources CHAPTER Methodology ARCHAEOLOGY OVERVIEW The SCVWCD constructed the Rinconada Water Treatment plant in The plant includes a large earthen embankment that is considered a dam under state regulation. The District underwent some enlargement and changes in function, finally becoming the SCVWD in the 1970s. The Gavilan Water Conservation District was annexed by the District in 1987 and the District assumed control of the Chesbro and Uvas dams. Little alteration of these dams has occurred since they were built. The District has made improvements to inlet structures and outlet gates, and made repairs to cracks caused by earthquakes. Far Western Anthropological Group, Inc. (Far Western) performed the review and assessment of archaeological resources within the Dam APE. The review included a literature and records search and ground surveys for previously undiscovered surface resources at the dam facilities. The literature review and the ground surveys are described below. LITERATURE AND RECORDS REVIEW Far Western performed a records search at the Northwest Information Center, Sonoma State University in August 2006 (Byrd and Berg 2006). The records search area consisted of a one-quarter-mile radius around the APE for each of the 14 dams. Far Western also performed a review of the Sacred Lands files from the Native American Heritage Commission (NAHC) in July 2006 for cultural resources in the project area. Far Western also requested a list of Native American individuals or organizations in the region that might be interested in the project and sent letters to all the Native American individuals and groups on the list provided by the Commission. ARCHAEOLOGY SURVEY METHODOLOGY Far Western performed ground surveys for previously undiscovered surface resources. The project APE was subjected to varied levels of archaeological investigations as described below: 1. Class III Pedestrian Surveys. Portions of each of the dam sites were subjected to intensive pedestrian surveys. The pedestrian surveys consisted of systematic coverage by a two-person crew with a spacing interval of 5 to 15 meters, depending on conditions. Given that dried grasses or duff often obscured the ground surface, the survey methodology included paying particular attention to any rodent disturbed dirt piles, and periodically scraping aside vegetative cover for surface artifacts and archaeological sites. June 2011 Page 3-190

243 Section 3.6 Cultural Resources CHAPTER 3 2. Reconnaissance Surveys. Reconnaissance surveys were performed in areas where steep slopes or dense vegetation made Class III pedestrian surveys exceedingly difficult. The reconnaissance surveys require looking for similar surface artifacts as in the Class III pedestrian surveys. The main difference is that the reconnaissance surveys do not cover entire areas as comprehensively as the Class III surveys. The reconnaissance survey covers as much of the area as is practical. For steep-sloped areas, the reconnaissance surveys generally entailed surveying the upper and lower edges, while survey of areas covered with dense brush was limited to gaps where access was possible. 3. Not Surveyed/Excluded. Portions of the APE were not surveyed due to a variety of factors. These factors included steep, mechanically cut slopes (particularly adjacent to spillways), borrow areas, constructional fill areas, steep natural slopes deemed too dangerous to walk (and also unlikely to contain cultural resources), and, occasionally, areas with impenetrable brush or dense concentrations of poison oak. The excluded areas also include the dam faces, their associated structures (spillways, paved roads), and areas under water. The dam faces constitute roughly 54 percent ( acres) of the project area (Byrd and Berg 2006). The dams and their associated structures lack the possibility of having surface archaeology because they are manmade features that required fill gathered for construction. Any archaeological evidence would have been uncovered/destroyed/removed when the structures were originally built. ARCHAEOLOGICAL SURVEY RESULTS Surface Resources No new archeological sites were located during the survey. There are three previously recorded archaeological sites within the project area. These previously recorded sites are prehistoric flake scatters that could not be relocated during the archaeological survey. Buried Resources Archaeologists have long recognized that a significant portion of the archaeological record may lie buried beneath the alluvial fans and floodplains that form the valley floors of central California. Although such buried resources cannot be detected during traditional archaeological surface survey, it is possible to distinguish which areas of the modern landscape have potential for buried resources and which landforms are either too old to contain such archaeological remains or which were formed by processes that are unlikely to have preserved intact cultural remains. An archaeological sensitivity model was prepared based on the results of the literature review, ground surveys, and maps. The sensitivity model shows which areas of the project APE have the greatest potential for buried archaeological deposits. The results are listed in Table June 2011 Page 3-191

244 Section 3.6 Cultural Resources CHAPTER 3 Table 3.6-2: Archaeological Buried Site Sensitivity Classification Based on Geomorphic Mapping No Sensitivity Low Sensitivity Medium-High Sensitivity Acres % Acres % Acres % Total Acres Almaden Dam Anderson Dam Calero (all dams) Chesbro Dam Coyote Dam Coyote Percolation Ponds Dam Guadalupe Dam Lenihan Dam Rinconada Treated Water Reservoir Stevens Creek Dam Uvas Dam Vasona Dam Total SOURCE: Byrd and Berg 2006 Approximately 85 percent of the APE has no sensitivity for buried archaeological sites. This is due in part to the fact that the actual dam footprint comprises a large percentage (54 percent) of the project APE. The footprint is imported fill and has no potential for buried resources. Another 5.7 percent of the APE has low sensitivity. The remaining 9.5 percent of the project APE is classified as medium-high sensitivity for buried cultural resources. The areas of highest sensitivity are not identified here for protection of any potential resources consistent with California Government Code The areas of highest sensitivity are generally found in previously undisturbed areas within the DMP APE. HISTORIC RESOURCES OVERVIEW A historic resources review was prepared by JRP Historical Consulting, LLC (Herbert et al. 2006) to determine the historical status of the dams and related structures. The review included a literature review of public records, including the records of dam construction available at the District. The inventory and evaluation team also conducted site visits. June 2011 Page 3-192

245 Section 3.6 Cultural Resources CHAPTER 3 LITERATURE AND RECORDS REVIEW Research was conducted at the California State Library, Water Resources Center Archives, Bancroft Library, San Jose Public Library, DSOD, and Shields Library at UC Davis. Background research was also conducted through a review of the historic records at the SCVWD, where records and photographs of the construction of the dams were collected. JRP gathered information about the general Santa Clara Valley area using maps and secondary sources. Research also included industry-specific information regarding the dams, including reports written by Fred Tibbetts and a report by the American Society of Civil Engineers (ASCE): Historic Landmarks of San Francisco and Northern California (ASCE 1977). HISTORIC RESOURCES SURVEY METHODOLOGY JRP conducted a reconnaissance survey at each dam site to view the dams and their appurtenant structures. JRP conducted a second field visit to the dam sites to photograph, survey, and record each dam and their associated structures. HISTORIC SURVEY RESULTS Historical significance is judged by application of four criteria, as follows: Criterion A: association with events that have made a significant contribution to the broad patterns of our history Criterion B: association with the lives of persons significant in our past Criterion C: resources that embody the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components may lack individual distinction Criterion D: resources that have yielded, or may be likely to yield, information important to history or prehistory JRP concluded that 8 of the District s 14 dams meet the criteria for listing in the NRHP and the California Register of Historical Resources (CRHR) as contributors to a discontiguous historic district under Criterion A, for their association with the Santa Clara Valley water supply history. In addition, JRP determined the 1930s dams to be eligible under NRHP Criterion C because the dams are a significant example of engineering design by master engineer Fred Tibbetts. June 2011 Page 3-193

246 Section 3.6 Cultural Resources CHAPTER 3 The original eight dams constructed in the 1930s include: Almaden Dam Calero Main Dam Calero Auxiliary Dam Coyote Dam Coyote Percolation Ponds Dam Guadalupe Dam Stevens Creek Dam Vasona Dam The remaining dams (those constructed in the 1950s) do not meet the criteria for listing in the NRHP nor the CRHR, and thus are not historically significant under CEQA guidelines (Herbert et al. 2006). Fellows Dike is not included in the Historic District because it was not a part of the original design for groundwater percolation. The dike was built after Calero Main and Auxiliary dams, and its purpose was to protect the adjacent ranch property from flooding. 1930s Dams The District s 1930s dams are the original and integral units of its system, which played a significant role in providing water to the Santa Clara Valley and maintaining higher groundwater levels. The District s system was important in the economic development of the Santa Clara Valley because this system of dams provided a steady, reliable, and consistent supply of water for municipal, industrial, and agricultural uses. The construction of the eight dams to act as a unified system provided for continued development of the Santa Clara Valley on a large scale and provided a supply more certain that that which might have been provided by any single such structure. Construction and operation of the District system, as a whole, played a significant and lasting role in the economic development of the region. In addition, it is the design of the dams as a system, established to enhance groundwater supplies, that was recognized by the ASCE as one of their Historic Landmarks of San Francisco and Northern California (ASCE 1977). The dams retain integrity of design, workmanship, and materials, and association (as part of the District s system). All of the dams have a strong sense of time and place that a visitor receives while at or while viewing the site. The dams are widely separated by distance; therefore, the dams are considered a discontiguous district, in which the dams and their appurtenant features are considered contributing elements. For the purposes of this evaluation, the SCVWD 1930s dams discontiguous district boundaries are the footprint of the individual dams themselves. June 2011 Page 3-194

247 Section 3.6 Cultural Resources CHAPTER 3 The 1950s-Era Dams The remaining five dams, Anderson Dam, Lexington Dam (now Lenihan Dam), Uvas Dam, Chesbro Dam, and Rinconada Treated Water Reservoir Dam, were either built by the District or by other districts that have since been subsumed into the District. These dams were additive to the original plan, and provide additional water supplies. They were built after a significant period of time had passed since construction of the original dams, and in two cases by a different agency, so that they should be considered as separate resources and not as part of the discontiguous district or as a district of their own. These dams do not have a direct connection to the original plan, or to engineer Tibbetts, and thus do not appear to meet the criteria for listing in the National Register or California Register. PALEONTOLOGICAL RESOURCES San Francisco Bay has a rich fossil history, especially from the Pleistocene age. Mammals such as elephants, camels, rhinos, sloths, mammoths, and saber-toothed cats roamed through the region tens of thousands of years ago. In July 2005, bones from a Columbian Mammoth were found in a drainage ditch along the Guadalupe River, just north of West Trimble Road and the Mineta San Jose Airport. There are likely other fossils within the Guadalupe watershed and Santa Clara County REGULATORY SETTING Federal Activities requiring decisions and or approvals from federal agencies would trigger compliance with the following federal laws. NATIONAL HISTORIC PRESERVATION ACT Section 106 of the National Historic Preservation Act regulates actions by federal agencies that may affect known or unknown cultural and historical resources. Cultural properties that could be discovered on any of the project lands as a result of implementation of the program would be subject to the National Historic Preservation Act. Some of the District activities may require a permit under Section 404 of the Clean Water Act; this permit would trigger Section 106 compliance for the project. NATIVE AMERICAN GRAVES PROTECTION AND REPATRIATION ACT OF 1990 The Native American Graves Protection and Repatriation Act (NAGPRA) provides for protection of Native American graves and all objects associated with ritual and burial. The Act establishes conditions for the excavation and removal of Native American remains and artifacts, notification requirements for inadvertent discovery of Native American remains, and criminal penalties for illegal possession. The Act directs federal agencies to identify the geographic and tribal origins of Native American remains and artifacts, and requires the repatriation of remains. This Act would apply June 2011 Page 3-195

248 Section 3.6 Cultural Resources CHAPTER 3 if there is a federal action related to the project, such as the issuance of a Section 404 permit. ARCHAEOLOGICAL RESOURCES PROTECTION ACT The Archaeological Resources Protection Act (ARPA) was enacted to secure, for the present and future benefit of the American people, the protection of archaeological resources and sites which are on public lands and Indian lands, and to foster increased cooperation and exchange of information between governmental authorities, the professional archaeological community, and private individuals. (Sec. 2(4)(b)) State CEQA CEQA requires a review to determine if the project will have a significant effect on archaeological sites or properties of historic or cultural significance to a community or ethnic group eligible for inclusion in the CRHR. If implementation of a project results in significant effects on historical resources, then alternative plans or mitigation measures must be considered. PRC SECTION PRC Section stipulates that any resource listed in, or eligible for listing in, the CRHR is presumed to be historically or culturally significant. Resources listed in a local historic register or deemed significant in a historical resources survey (as provided under PRC Section g) are presumed historically or culturally significant unless the preponderance of evidence demonstrates they are not. A resource that is not listed in or determined to be eligible for listing in the CRHR, not included in local register or historic resources, or not deemed significant in a historical resource survey may nonetheless be historically significant. This provision is intended to give the Lead Agency discretion to determine that a resource of historic significance exists where none had been identified before and to apply the requirements of PRC Section to properties that have not previously been formally recognized as historic. PRC SECTION Section provides that where a project may adversely affect a unique archaeological resource, the Lead Agency must treat that effect as a significant environmental effect, and provides for more specific mitigation measures if the impact cannot be avoided. PRC Sections and operate independently to ensure that potential effects on archaeological resources are considered as part of a project s environmental analysis. Either of these benchmarks may indicate that a project may have a potential adverse effect on archaeological resources. June 2011 Page 3-196

249 Section 3.6 Cultural Resources CHAPTER 3 PRC SECTION , CCR SECTION 4850 ET SEQ. The CRHR (Public Resources Code (PRC) Section ) is a listing of those properties that are to be protected from substantial adverse change, and it includes properties that are listed, or have been formally determined to be eligible for listing in, the NRHP, State Historical Landmarks, and eligible Points of Historical Interest. A historical resource may be listed in the CRHR if it meets one or more of the following criteria: It is associated with events that have made a significant contribution to the broad patterns of local or regional history, or cultural heritage of California or the United States; It embodies distinctive characteristics of a type, period, or method of construction, or represents the work of a master or possesses high artistic values; or It has yielded or has the potential to yield information important in the prehistory or history of the local area, California, or the nation. PRC SECTION PRC Section discusses the procedures to follow upon the discovery of Native American human remains. NAHC, upon notification of the discovery of human remains by the coroner, is required to notify those persons it believes to be most likely descended from the deceased Native American. It enables the descendant to inspect the site of the discovery of the Native American human remains and to recommend to the landowner (or person responsible for the excavation) means of treating, with dignity, the human remains and any associated grave goods. PRC SECTIONS , PRC Section and establish that it is a felony to obtain or possess Native American artifacts or human remains taken from a grave or cairn. They also mandate that it is the policy of the State to repatriate Native American remains and associated grave goods. HEALTH AND SAFETY CODE SECTION Health and Safety Code Section defines procedures for the discovery and treatment of Native American remains. HEALTH AND SAFETY CODE SECTIONS Health and Safety Code Sections provides a consistent State policy to ensure that all Indian human remains and cultural materials are treated with dignity and respect. The code extends policy coverage to non-federally recognized tribes, as well as federally recognized groups. June 2011 Page 3-197

250 Section 3.6 Cultural Resources CHAPTER Local SANTA CLARA COUNTY GENERAL PLAN The Santa Clara County (1994) General Plan contains strategies, policies and implementation directives regarding the general approach to the County s cultural heritage resource protection. C-RC 49 states that cultural heritage resources within Santa Clara County should be preserved [and] restored wherever possible and commemorated as appropriate for their scientific, cultural, historic and place values. Policy C-RC(i)26 states that historic district designations should be explored to preserve character of areas rich in heritage resources. Policy C-RC 50 states the approach to heritage resource protection should include the following strategies: Inventory and evaluate heritage resources Prevent or minimize adverse impacts on heritage resources Restore, enhance, and commemorate resources, as appropriate Policy C-RC 54 states that heritage resources should be restored, enhanced, and commemorated as appropriate to the value and significance of the resource. CITY OF SAN JOSE GENERAL PLAN The City of San Jose General Plan contains policies regarding the general approach to the City s historic, archaeological, and cultural resource protection. The City of San Jose has a single goal pertaining to cultural resources, Preservation of historically and archaeologically significant structures, sites, districts, and artifacts in order to promote a greater sense of historic awareness and community identity and to enhance the quality of urban living. Applicable policies include: Preservation of historically or archaeologically significant sites, structures, and districts should be a key consideration in the development review process. Areas with a concentration of historically and/or architecturally significant sites or structures should be considered for preservation through the creation of Historic Preservation Districts. For proposed development sites which have been identified as archaeologically sensitive, the City should require investigation during the planning process in order to determine whether valuable archaeological remains may be affected by the project and should also require that appropriate mitigation measures be incorporated into the project design. The City should encourage the continuation and appropriate expansion of Federal and State programs which provide tax and other incentives for the rehabilitation of historically or architecturally significant structures. June 2011 Page 3-198

251 Section 3.6 Cultural Resources CHAPTER SIGNIFICANCE CRITERIA The project would have significant effects on cultural resources if it would: Cause a substantial adverse change in the significance of an archaeological resource as defined in , and/or disturb human remains, including those interred outside of formal cemeteries Cause a substantial adverse change in the significance of historical resource as defined in Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature IMPACTS AND MITIGATION Impact: Cause a Substantial Adverse Change in the Significance of an Archaeological Resource as Defined in , and/or Disturb Human Remains, Including Those Interred Outside of Formal Cemeteries OVERVIEW Ground disturbance in previously undisturbed areas of the APE could affect archaeological resources. The vast majority of the project APE outside the dams themselves was subjected to Class III or reconnaissance level archaeological surveys. No new archaeological sites were located during these surveys. There are only a few areas within the project APE that are undisturbed. Maintenance work is unlikely to occur in previously undisturbed areas; therefore, it is unlikely that archaeological resources would be impacted by the DMP. Activities would likely occur in areas of previous disturbance where any potential resources would already have been discovered, removed, and/or destroyed at the time of the original construction. If work is necessary in a previously undisturbed area, mitigation would be implemented to prevent or minimize impacts to any previously undiscovered and potentially significant archaeological resources. Impacts to archaeological resources would be less than significant with implementation of mitigation. SURFACES AND/OR EARTHWORK Surfaces work includes vegetation management, rodent control, access road and boat ramp work, erosion control and bank hardening, embankment repairs, and trash and debris removal. VEGETATION MANAGEMENT Vegetation management, except in the case of tree removal, would not disturb the subsurface. Vegetation removal would be limited to the face of the dam, and immediately adjacent areas, which would not affect any archaeological resources (the dam faces are built from imported fill material that would not contain cultural resources). June 2011 Page 3-199

252 Section 3.6 Cultural Resources CHAPTER 3 Tree removal on dam faces (such as at Almaden and Vasona dams) would not disturb buried cultural resources because the area is imported fill. Tree removal from areas other than dam faces could require subsurface disturbance and may result in impacts to unknown cultural resources. MM Cultural-1, which requires a consultation with a professional archaeologist prior to excavation and ground disturbance in areas classified as medium-high for buried cultural resources, would be implemented to reduce this potentially significant impact to a less than significant level. The District will also implement BMP CU-2 and CU-3 in all project activities which serve to further reduce the potential impact to cultural resources. BMP CU-2 requires work be halted in the event an unanticipated discovery is made during work activities and reviewed by a qualified professional. BMP CU-3 implements state law that defines the actions that should take place if human remains are discovered during maintenance activities. Mitigation Measure MM Cultural-1: If a project entails excavation or disturbance of subsurface sediments in an area classified as medium-high for buried cultural resources as identified in Far Western s Report: Cultural Resources Investigations for the Dam Maintenance Program, Santa Clara County, California and the area has not been previously surveyed for cultural resources, then a professional archaeologist shall be consulted as to the best course of action. This might include backhoe work or monitoring of excavations to determine the presence or absence of buried resources. BURROWING RODENT CONTROL Burrowing rodent control would be limited to the dam faces and surrounding access roads. Burrowing rodent control involving rodenticides or trapping would not require subsurface disturbance. Burrowing rodent control would also include filling burrows on the dam faces and immediately adjoining areas after rodent elimination. Filling burrows would not disturb any archaeological resources because the activity occurs only in areas that have been previously disturbed. EROSION CONTROL, BANK STABILIZATION, AND EMBANKMENT REPAIRS Erosion control may be needed anywhere on the dam surface or surrounding areas, but particularly along areas with steep slopes. Bank stabilization would occur in the stilling basins at stream tailwaters and in plunge pools and at the base of the spillways. Embankment repair could be required to repair slumps anywhere on the dam face after seismic events or movement. The areas in which these activities would occur were created during dam construction and are considered disturbed areas, although they are close to the historic stream course. Stream and riparian corridors tend to have a higher potential to yield archaeological resources since settlements were often based around water bodies. Ground excavation required for installation of riprap in the stilling June 2011 Page 3-200

253 Section 3.6 Cultural Resources CHAPTER 3 basins or along slopes in previously undisturbed areas within the DMP footprint would have a small potential to uncover previously undiscovered cultural resources or human remains. MM Cultural-1, and BMP CU-2 and CU-3 would be implemented to minimize potentially significant effects to cultural resources to less than significant levels. ROAD AND BOAT RAMP MAINTENANCE Road maintenance would occur on District owned access roads. The roads are primarily along the crest of the dam to the toe of the dam. Almaden Dam and Guadalupe Dam have boat ramps that the District maintains. Maintenance activities on these ramps would generally include fixing concrete and surfaces. Some road stabilization work may require slope stabilization and buttressing soils over and below roads, potentially close to and/or within riparian habitat. Some new roads and temporary roads may also be built. Where road maintenance activities involve native soils, there is a small potential to uncover previously undiscovered archaeological resources. MM Cultural-1 would be implemented in areas classified as medium-high for buried cultural resources. With the implementation of mitigation when necessary and standard BMPs, the potential impact is less than significant. DEBRIS REMOVAL Debris removal could involve the use of heavy equipment to remove and crush debris. Crushing activities would only be staged in a previously disturbed area. Removal of other debris around the dams and spillways would not involve disturbance of new ground. Debris removal would have no potential to affect archaeological resources. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Appurtenant structures include the inlet/outlet structures, valves, fish screens, outlet pipe and tunnels, concrete structures, and hydraulic systems. Maintenance of these structures would generally not require new ground disturbance and would not impact cultural resources. Removal of sediment is not likely to have any impact on archaeological resources (or prehistoric human remains) because any sediment that may have accumulated at the inlet structure or along the hydraulic lines would not be native sediment and therefore would not contain cultural resources. The sediment to be removed most likely settled from the face of the dam (upstream face) or was transported sediment that has settled from the surface of the reservoir. The likelihood of impacting archaeological resources by the uncovering of human remains during maintenance of appurtenant structures would be minimal. Structures on the dam face would not have a potential for unearthing significant cultural resources because the dams are made of imported fill (any cultural material found within a dam, if any, would be out of its original context). Some ancillary structures that are located off of the dam face (such as some control houses, or seepage monitoring weirs, etc.) may need maintenance that includes excavation. There is a very remote possibility that construction could impact a previously undiscovered June 2011 Page 3-201

254 Section 3.6 Cultural Resources CHAPTER 3 cultural resource during excavation or ground disturbing work. MM Cultural-1 would be implemented in areas with medium-high potential for buried cultural resources. Implementation of MM Cultural-1 with BMP CU-2 and CU-3 would minimize potential effects from maintenance of appurtenant structures to less than significant levels. Seepage monitoring systems may be installed or modernized under the DMP. Installation or modernization of these systems may require excavation at the toe of the dam and throughout the dam. Excavation on the dam surface would not have a potential to impact cultural resources, because the dam surface is made up of imported or non-native soils. Excavation off of the dam within native soils could have a small potential for impacting previously undiscovered resources. MM Cultural-1 and BMP CU-2 and CU-3 would be implemented to minimize potential effects to less than significant levels. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring involve periodic visual and pedestrian surveys of the dam facilities that do not involve ground disturbance that could impact archaeological resources. Exploratory work would include excavations, backfill, and compaction, temporary access roads, drilling, and/or borings for geotechnical work or work required by DSOD. Exploratory work would most likely occur on the dam itself, but could also be required anywhere within the identified APE, including from barges within the reservoir. Exploratory work would have the potential to impact previously undiscovered cultural resources if it occurs in previously undisturbed soil. Implementation of mitigation measure MM Cultural-1 and BMPs CU-2 and CU-3 would reduce effects to less than significant levels. RESERVOIR DEWATERING Reservoir dewatering has the potential to expose previously submerged banks and undisturbed areas that could reveal previously undiscovered archaeological resources. However, the water level in the reservoirs is regularly raised and lowered; therefore, the banks were likely exposed in the past. Reservoir lowering would not include any work by the District within the reservoir that would include disturbance to areas previously underwater. Additionally, resources would not be readily visible due to overlaying sediments. With implementation of MM Cultural-1, impacts to cultural resources from reservoir dewatering would be less than significant. June 2011 Page 3-202

255 Section 3.6 Cultural Resources CHAPTER Impact: Cause a Substantial Adverse Change in the Significance of a Historical Resource as Defined in OVERVIEW According to JRP s survey, eight dams are considered eligible for the NRHP as previously described. The eight dams include: Almaden Dam Calero Main Dam Calero Auxiliary Dam Coyote Percolation Ponds Dam Guadalupe Dam Stevens Creek Dam Vasona Dam Coyote Dam JRP determined that the remaining six dams and their associated structures (Anderson Dam, Lenihan Dam, Chesbro Dam, Uvas Dam, the Rinconada Treated Water Reservoir Dam, and Fellows Dike) are not historic resources nor are they eligible for listing in the NRHP. There are no other historic structures or features within the APE. The eight dams determined to be eligible for listing in the NRHP are eligible based on their function as a system, and for the specific engineering of that system to recharge and maintain groundwater levels with the Santa Clara Valley. The system was important in the economic development of the Santa Clara Valley because it provided a steady, reliable, and consistent supply of water for municipal, industrial, and agricultural uses. While any dam might be considered important this way, the construction of the eight dams as a unified system provided for continued development on a larger scale and provided a supply that was more certain than by any single structure. When considering potentially significant impacts to a historic district, the reason for its eligibility must be considered. Changes that affect the dam system s function and engineering could significantly impact the NRHP eligibility of the eight dams. The significance of the resource lies within its function as a system, which allows for a number of minor changes on each individual dam without significantly affecting the overall historic status of the system. The NRHP eligibility of the eight dams would be significantly impacted if the dams were demolished in whole or in part. Significant changes could include (but are not limited to): Removing a spillway and rebuilding at a different location; Lowering or raising the dam; Changing the shape and appearance of the dam surface and function (e.g., such as from an earthen to a concrete dam); Changing the outlet pipe to a tunnel or other visibly different system; or Completely removing one of the dams. June 2011 Page 3-203

256 Section 3.6 Cultural Resources CHAPTER 3 DMP activities, which could cause minor changes to structures and the appearance of individual dams, would not impact the significance of the historic district. DMP activities would result in changes to ancillary structures, removal or control of vegetation, road surfaces, and potentially the addition of minor new structures and instruments (piezometers, solar panels, electrical control systems, etc.). All of these activities would change the appearance of the facilities, but would not alter their function as an earthen dam or the operation of the overall system. Activities such as vegetation and burrowing rodent control, concrete repair, and painting serve to maintain the dams as they were built. Changes in instrumentation would not affect the historic nature of the dam or the district. The effects of the DMP on historic resources would be less than significant Impact: Directly or Indirectly Destroy a Unique Paleontological Resource or Site or Unique Geologic Feature Activities that cause surface disturbance in areas not previously subject to disturbance have the potential to uncover paleontological resources (similar to the activities described above that could affect archaeological resources). Road repair, erosion control, and bank stabilization all have some potential to unearth paleontological resources because of the location of where this work would occur, near and within alluvial fan deposits. Installation of structures such as new piezometers, survey monuments, blockhouses, or fences in new areas has a limited potential for unearthing paleontological resources. Exploratory work could also unearth resources. Exposure of a paleontological resource could lead to its destruction, which would be a significant impact. MM Paleo-1 would minimize any potential effects to paleontological resources from any activities in the DMP that involve ground disturbance work to less than significant levels. Reservoir dewatering would not require significant surface or ground disturbance. However, drawing down water levels may expose potentially significant undiscovered paleontological resources. Discovery of a significant resource is unlikely since no discoveries have been made during historic instances of reservoir dewatering. Sediments would most likely obscure any significant finds and reduce chances of discovery. MM Paleo-1 would be implemented if a discovery is made and impacts to paleontological resources would be reduced to less than significant levels. MITIGATION MEASURE MM Paleo-1: If paleontological resources are discovered during any activity, all work shall be suspended in the immediate area, or if the resources are in-stream, the site will be isolated from the live stream. Once the site is secure, a qualified paleontologist shall be contacted to investigate and evaluate the discovery. If sensitive resources are identified, the site shall be avoided or data collection shall be implemented, as recommended by a paleontologist, to retain and/or record the information contained in the site. June 2011 Page 3-204

257 Section 3.6 Cultural Resources CHAPTER MITIGATION MEASURES MM Cultural-1: If a project entails excavation or disturbance of subsurface sediments in an area classified as medium-high for buried cultural resources as identified in Far Western s Report: Cultural Resources Investigations for the Dam Maintenance Program, Santa Clara County, California and the area has not been previously surveyed for cultural resources, then a professional archaeologist shall be consulted as to the best course of action. This might include backhoe work or monitoring of excavations to determine the presence or absence of buried resources. MM Paleo-1: If paleontological resources are discovered during any activity, all work shall be suspended in the immediate area, or if the resources are in-stream, the site will be isolated from the live stream. Once the site is secure, a qualified paleontologist shall be contacted to investigate and evaluate the discovery. If sensitive resources are identified, the site shall be avoided or data collection shall be implemented, as recommended by a paleontologist, to retain and/or record the information contained in the site. Residual Impacts After Mitigation All impacts would be reduced to less than significant levels with implementation of the mitigation described here. Best Management Practices See the Mitigation Monitoring and Reporting Program (Appendix V) for complete text of BMPs CU-2: Stop Work and Report Archeological Finds CU-3: Stop Work and Report Burial Finds June 2011 Page 3-205

258 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER GEOLOGY, SOILS, AND MINERAL RESOURCES ENVIRONMENTAL SETTING Topography REGIONAL OVERVIEW Santa Clara County lies at the southern end of San Francisco Bay. The County has four distinct physiographic regions or landscape units (SCBWMI 2001): Santa Cruz Mountain uplands Diablo Range uplands Foothills of the Santa Cruz Mountains and the Diablo Range Bay plains and alluvial valleys Refer to Figure 2.1-1, which shows the topographic relief within the County. The District s reservoirs (and dams) are primarily situated within the Santa Cruz Mountain uplands, the Diablo Range uplands, or the foothills. The Coyote Percolation Ponds Dam is located in the Bay plains. SANTA CRUZ MOUNTAINS The Santa Cruz Mountains occur along the western boundary of the County and includes rugged terrain characterized by steep slopes and v-shaped canyons. Elevations range from about 500 to 3,000 feet above mean sea level, and slope steepness ranges from about 15 to 75 percent. Average rainfall in this region is the highest in the County, ranging from 30 to over 50 inches per year. Vegetation is predominantly forest, but includes some chaparral and grasslands (SCBWMI 2001). Almaden Dam, Guadalupe Dam, Stevens Creek Dam, Chesbro Dam and Uvas Dam are all located at the lower elevations of the Santa Cruz Mountain ranges. DIABLO RANGE The Diablo Range region is farther inland on the east side of the County and differs from the Santa Cruz Mountains uplands because of a drier climate. The region is topographically defined by narrow ridges and deep valleys with little or no flood plain area. Elevations range from about 500 to 2,800 feet above mean sea level, with slopes similar to those of the eastern Santa Cruz Mountains. The Diablo Range sustains less protective vegetation because of the lower average rainfall (ranging from 20 to 32 inches). The vegetation consists of a mix of annual grasslands, oak woodland and chaparral (SCBWMI 2001). Anderson Dam was built across a former gorge through the Yerba Buena Ridge. This long ridge flanks the western edge of the Diablo Range (Stoffer and Messina 2002). Coyote Dam is also located within the Diablo Range. June 2011 Page 3-206

259 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 FOOTHILLS OF THE SANTA CRUZ MOUNTAINS AND DIABLO RANGE Foothill areas have moderate slopes, rarely exceeding 20 percent. Rainfall averages about 20 inches per year for both east and west foothills. Characteristic vegetation includes savannah, composed of annual grasslands, scattered oaks, and chaparral. Calero Main Dam, Calero Auxiliary Dam, and Fellows Dike are located at the edge of the Santa Cruz Mountain Range, to the west of where it meets the Diablo Range at a junction known as Coyote Narrows. Calero Dam is located within a foothill region, with the steeper mountains of the Santa Cruz Mountain Range immediately to the west of the reservoir, and more gently rolling slopes to the east. The Rinconada Treated Water Reservoir Dam is located within the foothill region of the Santa Cruz Mountains. Gravity is used to help deliver water to the many developed areas within the bay plains. Vasona Dam is located within a residential area of Los Gatos. Lenihan Dam (on Lexington Reservoir) is located within the foothills of the Santa Cruz Range. BAY PLAINS AND ALLUVIAL VALLEYS The plains and alluvial valleys are situated between the base of the foothills and the shoreline of the San Francisco Bay, and reflect more recent geomorphic processes. This landscape unit is composed of flat- to nearly flat-bottomed valleys and plains with extensive areas of artificial fill and a broad alluvial apron of fan, floodplain, and deltaic deposits derived from the adjacent mountain ranges (SCBWMI 2001). The Coyote Percolation Ponds were originally created by gravel mining in the channel of Coyote Creek. The Coyote Percolation Ponds Dam is the only facility included in the DMP which is located within the Bay plains and alluvial valleys Soils OVERVIEW The reservoir and dam sites were altered by filling and excavation during construction. Undisturbed soil is not found on the dam faces; fill material to create the dams was taken from nearby quarries (SCVWD 2004). Native soils still exist adjacent to the dams, as most of the dams are surrounded by natural environment. Soils beneath the dam faces and surrounding areas fall into 19 different soils series (NRCS 1958; NRCS 1974). Soils and surface deposits are described generally in Table Soils have also been discussed in detail in Section 3.2 Vegetation and Habitat, Table June 2011 Page 3-207

260 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 Topographic Region Santa Cruz Mountains Diablo Range Foothills Bay Plains and Alluvial Valleys Table 3.7-1: Characteristics of Soils by Topographic Region Dams in Region Almaden Dam, Chesbro Dam, Guadalupe Dam, Lenihan Dam, Stevens Creek Dam, Uvas Dam Anderson Dam, Coyote Dam Calero (Fellows Dike, Main, and Auxiliary) Dams, Rinconada Treated Water Reservoir Dam, Vasona Dam Coyote Percolation Ponds Dam SOURCE: Helley and Brabb 1971 General Soil Characteristics Surficial materials in the Santa Cruz Mountain Ranges are made up of clay and clay loam containing occasionally large, angular to rounded blocks of sandstone, chert, limestone, greenstone, schist, and gneiss. Soil covering of the Santa Cruz Mountains is considerably deeper than that of the Diablo Range, primarily due to greater rainfall. The Santa Cruz Mountain uplands have been dissected by faulting resulting in erosion. Recent erosion is composed of landslide deposits and clayey colluvium of the Holocene and late Pleistocene ages. Drier climate and vegetative differences limit the formation of deep soils in the Diablo Range, such as those found in the Santa Cruz Mountains, despite similar geology. The texture of the Diablo Range deposits depends on the relative position on the alluvial fan. Textures range from coarse sand and gravel to fine silt and clay. The western part of the range (where Coyote and Anderson dams are located) lies high on the alluvial fans and has permeable, medium-textured soils. With decreasing elevation from the west to east, soil textures become finer. The foothill region is underlain principally by older dissected and deformed alluvial fan deposits of the Quaternary period (less than 3.2 million years before present) and has well developed soil profiles. These deposits consist of weakly to moderately consolidated gravels and sand, with interbedded silt and clay that reflect the characteristics of the bedrock and surficial materials of the surrounding uplands. Older alluvial fans are moderately to deeply weathered, making available considerable amounts of easily erodible material. These deposits occur in areas of slight to moderately sloping topography, and are relatively stable unless disturbed. Valley areas are underlain by thick unconsolidated alluvium: gravel, sand, clay and silt that were deposited in the Holocene age. The texture of these deposits range from cobble to clay, mixed or interbedded laterally and vertically in places. These poorly consolidated deposits are often saturated and have little or no stability where geologically deformed or artificially altered. Valley margins are composed of solitary or coalesced alluvial fans The bay plains and alluvial valleys are primarily regions of sediment deposition. June 2011 Page 3-208

261 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 SERPENTINE SOILS The serpentine soil units are special because many plants able to establish on serpentine soils are rare and unique; serpentine environments support a number of endemic or nearly endemic species (USFWS 1998). Naturally-occurring asbestos is typically present in serpentine soils and serpentine rock within the County (discussed further in Section 3.5 Hazards and Hazardous Materials). Serpentine soils underlay portions of the project areas at Almaden, Calero Main, and Chesbro dams, and are located immediately adjacent to Anderson Dam. Figure shows the serpentine bedrock and soils cover for the County Seismicity and Tectonics REGIONAL SEISMICITY MAJOR ACTIVE FAULTS Santa Clara County is located in a seismically active region. The County is transected by the San Andreas and Calaveras Fault Zones. The Hayward Fault is an active nearby fault. Other potentially active faults in the area include the Stanford-Monte Vista, Sargent-Berrocal, Shannon, and San Gregorio. The San Andreas and Hayward faults are considered type A, according to the 1997 Uniform Building Code. These faults are capable of producing large magnitude events with a high rate of seismic activity (CGS 1996). The San Andreas Fault Zone is located near the west edge of the County in the Santa Cruz Mountains. The Calaveras Fault Zone bisects the County along the northwest-southeast trend through the Diablo Range. Faults in the region have been the source of several large historic earthquakes that have subjected the County to strong shaking and are considered sources of future large earthquakes. In 1838, an estimated 7.5 moment magnitude (Mw) earthquake occurred on the central San Francisco Peninsula. An earthquake along the Hayward Fault in 1868 had an estimated Mw of 7.0. The famous San Francisco earthquake of 1906 caused major damage and had an estimated Mw of 7.9. This great earthquake resulted from a rupture of approximately 270 miles with a maximum lateral displacement of 21 feet. The 1989 Loma Prieta earthquake, with a 6.9 Mw, was centered on a subsidiary fault of the San Andreas Fault about 11 miles southwest of Lenihan Dam. Major faults in the San Francisco Bay Area and time of last movement are shown in Figure June 2011 Page 3-209

262 Figure 3.7-1: Serpentine Bed Rock and Soil in Project Area June 2011 Page 3-210

263 Figure 3.7-2: Major Faults and Age of Faults in the San Francisco Bay Area June 2011 Page 3-211

264 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 EARTHQUAKE PROBABILITIES The USGS has assessed earthquake probabilities along faults in the Bay Area for the 30-year period from 2000 to 2030 (USGS 1999). The Association of Bay Area Governments (ABAG) has adopted these probabilities as planning guides, with maps that show expected seismic shaking intensity for different earthquake scenarios. According to the Working Group for Earthquake Probabilities, the probability for a large earthquake anywhere along the northern San Andreas Fault during the next thirty years is 21 percent (USGS 2008). The cumulative probability of a major earthquake (Mw 6.7 or greater) striking anywhere in the Bay Area within the next 30 years is 63 percent. Expected seismic shaking intensity and risk to structures is dependent on the distance from the earthquake epicenter, the magnitude of the earthquake, the underlying geologic, groundwater, and soil conditions, and the type of construction. According to ABAG maps, violent shaking of the region, equivalent to at least IX on the Modified Mercalli Intensity Scale (MMI), is expected from a rupture of the San Andreas fault, such as the 1906 earthquake produced. This corresponds to heavy damage, including anticipated serious damage to dams. According to the DSOD, the design earthquake for any dam-related structure is the maximum credible earthquake that the site will be subjected to from an active seismic source. A fault with evidence of rupture during the past 35,000 years is considered active. A fault with evidence of rupture during the last 1.6 million years, but with unknown activity during the past 35,000 years, is considered conditionally active. The maximum credible earthquake in the vicinity of the 14 dam locations is shown in Table Faults are shown in Figure Table 3.7-2: Maximum Credible Earthquakes on Nearby Faults Maximum Maximum CGS (DSOD) Activity Moment Credible Magnitude Earthquake (CGS/USGS)1 (Caltrans)2 San Andreas Fault Historic (active) Hayward Fault Historic (active) Calaveras Fault Historic (active) Monte-Vista/Shannon Late Quaternary (conditionally active*) Sargent-Barrocal Historic (active) San Gregorio Historic (active) Based on California Geological Survey (CGS), Open-File Report U.S. Geological Survey Open-File Report Caltrans California Seismic Hazard Map, * Late Pleistocene offset, last 35,000 years. SOURCE: SCVWD 2004; CGS 1996; Mualchin 1996 June 2011 Page 3-212

265 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 LOCAL TECTONICS OVERVIEW The dams are also affected by localized faults that are uplifting and creeping. Table below lists the localized faults that affect the geology in the vicinity of each of the dams. CALAVERAS FAULT Several of the area faults are capable of producing earthquakes. The most noteworthy is the Calaveras Fault, which passes through Coyote Dam. Coyote Dam is the only dam known to have been constructed over an actively creeping fault trace. Table 3.7-3: Local Faults Near Project Dams Calaveras Fault Uvas Antiform Coyote Creek Fault Ben Trovato/Barroca l Fault Lexington Fault Calero Fault Monte Vista- Shannon Fault Almaden Dam X X Anderson Dam X Calero Dams (Main, Auxiliary, Fellow Dike) X X 1 X Chesbro X Coyote X Coyote Percolation Ponds Guadalupe X X Lenihan X X Stevens Creek X Rinconada Treated Water Reservoir Dam X Uvas Dam X Vasona Dam X 1 Calero Fault is only found beneath the Main Dam SOURCE: SCVWD 2004; McLaughlin and Helley 2001; McLaughlin et al. 2001a; McLaughlin et al. 2001b; Bailey and Everhart 1964 June 2011 Page 3-213

266 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 The active trace of the Calaveras fault trends generally north-northwestward (upstream-downstream) in the left abutment of Coyote Dam. GPS and terrestrial survey results indicate that new monitoring points on the left abutment (west) side of the Calaveras fault are showing a very clear northwestward (N31 o W) trend of movement at a rate of approximately 14 millimeters per year (0.63 inches per year). This rate of fault movement, if assumed constant with time, suggests that the total fault movement in the left abutment since 1936 is on the order of 994 millimeters (3.3 feet). The dam was designed and constructed to withstand a total of about 20 feet of expected movement along the Calaveras fault during a large seismic event. This amount of offset was estimated by engineers and geologists based on the movement caused elsewhere by the 1906 San Francisco Earthquake. A series of high-angle, dip-slip fault traces, collectively referred to as the Right Abutment fault because they pass through the right abutment area of the dam, encompass a zone about 125 feet wide. The Right Abutment fault also passes through the foundation of the spillway and the outlet tunnel. Earth Science Associates (ESA and Calpine Corp. 1989) calculated an average uplift rate of 0.2 millimeters per year for the Right Abutment fault (of the main trace of the Calaveras) based on elevation differences and regional Quaternary chronology. Although minimal, uplift and differential movement along the Right Abutment fault has the potential to adversely affect the spillway and outlet tunnel. The outlet tunnel was specifically designed and constructed with shorter sections and flexible joints at the fault crossing to accommodate likely fault movement. The concrete spillway floor has recently experienced cracking and spalling that could be associated with Right Abutment fault movement. UVAS ANTIFORM McLaughlin et al. (2001b) mapped what they term the Uvas Antiform in the region between Almaden Reservoir to the north and Uvas Reservoir to the south. Almaden, Calero, and Chesbro dams lie along the northern limb, and Uvas Dam lies along the southern limb of the antiform structure (a fold where the rocks arch upward, or convex up, as opposed to a syncline where the rocks arch downward, or concave up). The Uvas Antiform is believed to have formed as a result of uplift of a late Pleistocene fluvial surface by about 20 feet (6 meters) (McLaughlin et al. 2001b). Assuming a continuous uplift of 6 meters during the last twenty thousand years, the estimated minimum rate of uplift rate is approximately 0.3 millimeters per year. The presence of this antiform suggests that the uplifted area may be bounded by blind thrust faults that have been active for at least 50,000 years and possibly in the Holocene (the name given to the last 11,000 years of the Earth s history, the time since the end of the last major glacial epoch, or ice age ). The relative youth of uplift of the Uvas Antiform is one line of evidence suggesting that blind thrust faults bordering the western edge of Santa Clara Valley are active (McLaughlin et al. 2000). The Uvas Antiform appears to be affecting Chesbro Dam. June 2011 Page 3-214

267 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER Geologic Hazards SEISMIC HAZARDS GROUND SHAKING AND FAULT RUPTURE Areas most susceptible to intense ground shaking are those located closest to the earthquake-generating fault, as well as areas underlain by thick, loosely unconsolidated and water-saturated sediments. Ground movement during an earthquake can vary depending on the overall magnitude, distance from the fault, focus of the earthquake energy, and type of geologic materials underlying the site (Mualchin 1996). All of the dams are susceptible to severe ground shaking, as discussed previously under Regional Seismicity. The only dam built on a known active fault trace is Coyote Dam. The dam and associated facilities could be subject to ground rupture in the event of an earthquake, although the dam has been designed to accommodate lateral movement up to 20 feet. LIQUEFACTION During severe ground shaking, saturated unconsolidated soils may lose cohesion and convert to a fluid-like state. This phenomenon is called liquefaction. It results from loss of soil shear strength induced by rapid ground shaking. Liquefaction can occur in areas characterized by less cohesive, granular materials that are water-saturated at depths less than 40 feet. The liquefaction zone covers the Santa Clara Valley floor, the lowlands along Coyote Creek, and the bottoms of several other creek canyons. Coyote Percolation Ponds Dam is located on the valley floor and has the highest susceptibility for liquefaction. Most other dams are also in or near small zones of liquefaction because of their locations along creeks and stream. Figure shows the liquefaction zones for Santa Clara County in relationship to the reservoir and dam locations. As part of the dam safety program, the District is currently investigating the base material of the dams. Potentially liquefiable has been found under a number of the dams, and investigations continue for others. Any repairs would be beyond the scope of the DMP and would be conducted under a separate project. SOILS HAZARDS EROSION Soils can be subject to erosion caused by both natural processes and human activities. Soils of the Santa Cruz Mountain Range show the most potential for erosion. Soils of the Diablo Range are less deep than those found in the Santa Cruz uplands; however, they are still susceptible to erosion. Older alluvial fans are moderately to deeply weathered, making available considerable amounts of easily erodible material. These deposits in moderately sloping topography are relatively stable unless disturbed. June 2011 Page 3-215

268 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 EXPANSIVE SOILS Shrink and swell movements occur in sediments containing expansive clays. Soils containing high clay content can expand when saturated, and contract when dried out. This shrink/swell movement can affect building foundations, often causing them to crack or shift, with resulting damage to the buildings they support. The soils found in the project area contain clay and therefore have the potential for shrink/swell movement; however, the dams and other associated buildings were engineered to overcome any potential for effects from shrinking and swelling. June 2011 Page 3-216

269 Figure 3.7-3: Liquefaction in Project Area June 2011 Page 3-217

270 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 LAND SUBSIDENCE Land subsidence is normally the result of groundwater withdrawal from compressible sediments. When groundwater is withdrawn, the effective pressure in the drained sediments increases. Compressible sediments are then compacted due to overlying pressures no longer being compensated by hydrostatic pressure from below. Compressible soils are mostly present in the northern part of Santa Clara County, near the San Francisco Bay. Compressible soils are generally not found in the foothill and mountainous regions where the dams were constructed. OTHER HAZARDS LANDSLIDES Landslides are masses of rock, soil, and debris displaced down-slope by sliding, flowing, or falling. Slides can result from certain geologic features, slope steepness, excessive rainfall, earthmoving disturbance, and seismic activity. Excavation and development activities often increase the incidence of landslides. Shaking during an earthquake may cause materials on a slope to lose cohesion and collapse. Landslide Hazard Zones have been identified within Santa Clara County. The majority of the reservoirs and dams are located within the steep slopes. Landslide hazards are prevalent in the mountainous and foothill areas where deposits coincide with bedrock distribution of the Central belt of the Franciscan Complex, much of which is highly sheared mélange, highly susceptible to land sliding. Steep slopes, active earthquake faults and areas of geologic instability are prevalent in both of the mountain ranges (Santa Clara County 1994). Figure shows areas designated by the County as Landslide Hazard Zones. There are landslides near several District dams Mineral Resources Mineral resources of significance found and extracted in Santa Clara County include construction aggregate deposits of limestone, and, to a lesser extent, salts derived from evaporation ponds at the edge of San Francisco Bay. Construction aggregates, such as sand, gravel, and crushed stone, have many purposes, including road and building construction (Santa Clara County 1994). There are a number of mineral resource deposits in Santa Clara County which are of regional or statewide significance as determined by state agencies. The County has nine quarries. Stevens Creek Quarry is located along Stevens Creek Reservoir and Lexington Quarry is located approximately 0.25 miles from the Lenihan Dam, along Alma Bridge Road. June 2011 Page 3-218

271 Figure 3.7-4: Landslide Hazard Zones in the Project Area June 2011 Page 3-219

272 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER REGULATORY SETTING State SEISMIC ZONES The Alquist-Priolo Earthquake Fault Zone Act was passed to prevent the construction of buildings used for human occupancy on the surface trace of active faults. The Act only addresses surface fault rupture and is not directed toward other earthquake hazards. The Act requires the State Geologist to delineate Earthquake Fault Zones along active faults within the state and to issue appropriate maps. An active fault under the Act is one that has moved in the last 11,000 years. The DMP does not include construction of new homes or structures that would be subject to the Alquist-Priolo Act. Some of the maintenance activities proposed, however, are designed to rectify features affected by fault movement (mainly in association with Coyote Dam). CALIFORNIA BUILDING CODE The California Building Code (CBC) is a modified version of the Uniform Building Code published in the United States by the International Conference of Building Officials. Standards and text were amended to reflect California earthquake conditions. Oversight of the CBC is assigned to the California Building Standards Commission, which, by law, is responsible for coordinating building standards Local SANTA CLARA COUNTY GENERAL PLAN GEOLOGIC HAZARDS The Santa Clara County General Plan acknowledges seismic and soils hazards in the unincorporated County. The following strategies have been established by the County to minimize risks to the public from geologic hazards: Inventorying hazards and monitoring changing conditions Maintaining low resident population densities within high hazard areas Designing, locating, and regulating development to avoid or withstand hazards Reduce the magnitude of the hazard, if possible Provide public information County General Plan strategies and policies include provisions such as prohibiting avoidable development on unstable land, requiring review by the June 2011 Page 3-220

273 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 County Geologist for projects with seismic hazards, filling and engineering development on expansive soils, etc. MINERAL RESOURCES The Santa Clara County General Plan includes provisions to protect mineral resources. Land use planning to preserve local mineral resources and ensure their future availability must: Protect existing and potential sites from development that would preclude mineral extraction. Assure that quarry access routes also remain available to large transport vehicles. Lenihan Dam and Stevens Creek Dam share access routes with quarries. CITY OF SAN JOSE SOIL AND GEOLOGIC CONDITIONS POLICY The City should cooperate with the s efforts to prevent the recurrence of land subsidence. EARTHQUAKE POLICY Responsible local, regional, state, and federal agencies should be strongly encouraged to monitor and improve the seismic resistance of dams in the San Jose area SIGNIFICANCE CRITERIA The project would cause significant effects if it would: Expose people or structures to substantial adverse effects from seismic hazards such as rupture of a known earthquake fault, seismic shaking, or liquefaction Cause soils hazards such as damage to structures from expansive or compressible soils or cause erosion of soils that could lead to instability or loss of top soils Cause slope instability (e.g., landslides) that could threaten life or property Result in the loss of availability of a known mineral resource that would be of value to the locality or region June 2011 Page 3-221

274 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER IMPACTS AND MITIGATION Impact: Expose People or Structures to Substantial Adverse Effects From Seismic Hazards Such as Rupture of a Known Earthquake Fault, Seismic Shaking, or Liquefaction OVERVIEW The District s facilities are located in a seismically active region. There may be some geologic effects to the dams in the case of ground shaking; however, these are previously existing conditions and are not a result of the proposed project. The proposed project activities would not create additional hazards related to seismicity, including rupture along faults, seismic shaking, and liquefaction. Project activities include regular preventative maintenance (through monitoring, inspections, and routine maintenance work) and corrective maintenance to repair damages caused by seismicity. The project would have an overall beneficial effect by improving the safety of the dams and associated facilities in the event of ground movement. SURFACES WORK AND/OR EARTHWORK Road surfaces, erosion control structures, or other surface features may become damaged in the event of an earthquake; however, life and property are not expected to be significantly affected. The DMP is designed to provide procedures to repair surface structures that are affected by natural elements. These impacts would be beneficial. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT The DMP includes concrete reconstruction and installation of new equipment, such as seepage monitoring pipes, weirs, piezometers, etc. Any small new structures or reconstructed buildings would be subject to the tectonic activity in the area; however, none of the new features would be sizable enough to cause damage to people or other substantial structures (such as the dam) in the event of an earthquake. The impact would be less than significant. In addition, new equipment would be designed and installed according to all building codes (such as in the case of reconstruction of a blockhouse) to minimize the potential effects of seismicity on built structures and human safety. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring include visual inspections as well as activities such as exercising the inlet and outlet valves and radial gates. Inspections and monitoring activities are meant to insure proper function and operation of systems and is a method for initiating repairs of any damaged facilities and to maintain the dams. Inspections and monitoring reduce potential effects to life and property from seismic activity by allowing for identification of damage and problem areas or structures that June 2011 Page 3-222

275 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 could fail during a seismic event. There would be no impact related to inspections and monitoring. Exploratory work often involves drilling boreholes or digging trenches to inspect underground features such as seepage collection piping, or drilling from barges in the reservoirs. Temporary access roads can be required. Exploratory work is conducted to identify potential structural problems (often related to seismicity) and is beneficial. Exploratory work would not cause or expose persons or property to any greater threats associated with seismic activity than with the existing conditions. Exploratory work would have no impact related to seismic activity. RESERVOIR DEWATERING Reservoir dewatering would be performed during planned preventative or corrective maintenance activities to allow personnel to access dam appurtenances or structures without the use of a diver. Dewatering the reservoir would not expose persons or property to greater threats associated with seismic activity than with existing conditions. Hydrostatic pressures against the dam face may change with reduced water levels; however, dam structures have been designed to withstand seismic activity during all conditions. Impacts would be less than significant Impact: Cause Soils Hazards Such as Damage to Structures From Expansive or Compressible Soils or Cause Erosion of Soils That Could Lead to Instability or Loss of Top Soils OVERVIEW Expansive soils may occur in areas near the dams, although project activities would not generally be affected by expansive soils. Re-construction, installation, or repair of structures and/or equipment would undergo proper engineering to minimize effects if structures would be located on expansive soils. Effects would be less than significant for all activities. Compressible soils can lead to subsidence. Only Coyote Percolation Ponds Dam is located within the valley s alluvium, which is subject to subsidence. Project activities would not involve the removal of water from groundwater pumping that could cause subsidence. There would be no effects from project activities that could cause damage to structures from subsidence. Several proposed activities have the potential to cause erosion, especially activities involving ground disturbance. Impacts are minimized through the implementation of erosion control BMPs and otherwise mitigated to less than significant levels through proposed mitigation measures. SURFACES WORK AND/OR EARTHWORK Vegetation removal would include tree removal, particularly at Almaden and Vasona Dam, but also along access roads and around structures. Areas of tree removal on dam faces would be revegetated with native grasses to reduce potential for erosion of the dam face to less than significant levels. Holes and loose soil from tree June 2011 Page 3-223

276 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 removal around structures or along roads would be filled and compacted. Effects would be less than significant. If permitted in the future, prescribed burning could lead to erosion. However, erosion control devices would be placed at the base of burned areas to minimize impacts associated with erosion and loss of topsoil consistent with BMP WQ-41. Burrowing rodent control would not facilitate erosion damage of the dam or other structures. Rodent burrows increase erosion of the dam face, which can increase instability on the dam face. Filling burrows and eliminating rodents would have a beneficial effect on the dam structure in minimizing erosion potential and minimize instability of the structure that could result from excessive erosion. Access roads are often subject to erosion damage. Road surfaces, drainages, and buffer zones would be maintained vegetation free, which could exacerbate erosion of the soils. Erosion impacts would be less than significant because the proposed maintenance activities would keep access roads in good condition and the roads are designed with drainage to limit erosion. Temporary access roads may need to be created in some situations. Temporary access roads would be constructed as graded and compacted soil surfaces. These surfaces would be maintained during the maintenance use so that vehicles can pass. Compaction and maintenance would minimize erosion. Once the temporary access was no longer needed, the continued presence of a temporary access road could result in significant soil erosion. MM Geology-1 would require the reclamation of temporary access road areas after maintenance (i.e., recontoured and revegetated) to minimize this potentially significant impact. The construction process for installation of bank hardening structures or features could cause temporary erosion impacts, but these would be less than significant. After installation, these features would minimize erosion. Erosion within waterways or that can affect water quality is addressed in Section 3.4 Hydrology and Water Quality. MITIGATION MEASURE MM Geology-1: Temporary access roads shall be recontoured and revegetated immediately after work requiring use of the roads is complete. Only native or non-invasive grasses shall be used to reclaim any temporary access road areas on dam faces. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Installation of new equipment or appurtenant structures may require minor surface grading. Standard erosion control methods would be used to control soil erosion during ground disturbing activities consistent with BMP WQ-41 and the site would be revegetated once work is complete. Effects to the structures or loss of top soil would be less than significant. June 2011 Page 3-224

277 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring work would not involve any actions that would lead to a loss of vegetated surfaces and erosion. Inspections and monitoring only involve visual surveys that would not include ground disturbance. There would be no impacts to erosion from ground disturbance. Exploratory work could be performed anywhere within the APE. Exploratory work could involve building temporary access roads (discussed above). Site preparation for exploratory drilling, trenching or borings could increase erosion of the soil in the area of the exploratory work. Bore holes, trenching, or drill holes would be properly filled after the work is complete. Erosion could occur if the work is performed during the rainy season. Exploration areas would be revegetated after work is complete to minimize erosion. Impacts would be less than significant. RESERVOIR DEWATERING Reservoir lowering could result in increased downstream flows that could cause significant bank erosion. Reservoir lowering could necessitate that water be released in amounts that are above the normal release rates. The amount and duration of the flow releases will determine the risks associated with potential stream bank erosion, but this is a potentially significant impact. This impact is addressed by MM General-3, which requires the District to prepare a detailed reservoir specific dewatering plan. This plan would determine specific release rates and methods for minimizing erosion risks to a less than significant level Impact: Cause Slope Instability (i.e., Landslides) That Could Threaten Life or Property OVERVIEW Most reservoirs are located in mountainous areas having steep slopes. Landslide hazards are prevalent in the mountainous and foothill areas where there are deposits of Franciscan Complex. Franciscan Complex includes highly sheared mélange 25, which is susceptible to land sliding. The reactivation of existing landslides or the formation of new slope instabilities would not be likely for most maintenance activities because activities would not occur on the unstable slopes. A very small potential exists to activate landslides during certain maintenance activities, such as access road work, vegetation management, or exploratory work that would occur on slopes. Landslide failure would be a potential hazard to maintenance workers at the site, recreational users down slope of such maintenance work, and to structures and vehicles. 25 A metamorphic rock formation created from sediments and rocks scraped off the top of a downward-moving tectonic plate (Houghton Mifflin Company 2004). June 2011 Page 3-225

278 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 SURFACES WORK AND/OR EARTHWORK Most surface and earthwork activities would not have the potential to activate landslides. Dam faces are engineered as a stable slope. Vegetation management and burrowing rodent control would mainly occur on the face of the dam and would not threaten the stability of the face of the dam. Erosion control and bank stabilization would occur in waterways or under spillways and would not be in an area that could initiate landslides. Surfaces work that could potentially affect slope stability would include road maintenance and some vegetation removal, such as tree removal. Road maintenance could include grading and use of heavy equipment. Some of the access roads (such as at Almaden and Guadalupe dams) are very steep as they traverse to the sides of the abutments towards the toe of the dam. Cutting into side slopes for roadwork could activate small landslides. These types of landslides could pose a potential threat to workers or vehicles and to the surface and function of the road, which is considered a potentially significant impact. MM Geology-2 requires the development of a Slope Stabilization Plan by a geosciences professional for road maintenance activities, and other similar work in areas with steep slopes. This measure would be implemented to reduce effects to less than significant levels for any roadwork that could involve cut into a slope. MITIGATION MEASURE MM Geology-2: If a maintenance activity is to be performed, or temporary maintenance road must be installed, that includes cut into an adjacent steep slope (steeper than 2:1), slope stability shall be considered by a geosciences professional. Based on results of the study, a Slope Stabilization Plan shall be developed that will apply industry accepted engineering design and applications to stabilize any unstable slopes in the road work area and will include measures for worker protection during construction activities. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures would not likely cause slope instability or initiate landslides. Most appurtenant structures are located on the dam, in the dam, at the base of the dam, or along the spillway which are engineered slopes. Piezometers and survey monuments are occasionally located on adjacent steep slopes surrounding most dams. These structures are relatively small, only about a square foot in area. Work on piezometers or survey monuments would be minimal, and would most often involve replacing lids. This sort of minimal work on slopes would not induce landslides because the work would be done manually without equipment in a small area and would not cause vibration or loss of soil cohesion that could induce landslide. A few maintenance activities, such as some spillway maintenance, or activities that require a temporary maintenance road, may threaten adjacent slope stability. Where these types of activities would be performed on slopes greater than 2:1 would implement MM Geology-2. With the implementation of this mitigation measure, impacts related to maintenance of appurtenant structures would be less than significant. June 2011 Page 3-226

279 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 INSPECTIONS, MONITORING, OR EXPLORATORY WORK Inspections and monitoring primarily involves visual and ground observation of the facilities and would not have a potential to induce landslides. Inspectors and or monitors may have to walk or climb into steeper areas to view structures or for desirable views of the reservoir and dams; however, inspection does not generally involve access into unsafe areas. If required, safety measures are used. The District trains field workers in worker safety and personal responsibility. Inspections and monitoring also involves activities such as exercising the inlet/outlet valves, which would not have impacts on slope stability. Exploratory work could involve activities such as drilling new test wells and installing piezometers along the dam, drilling boreholes for geotechnical studies in the abutments, in excavating and backfilling trenches and test pits, and in installing temporary access roads. Exploratory work could occur anywhere on the dam face or in surrounding areas (such as in surrounding bedrock to test for bedrock characteristics, etc.). Exploratory work could have the potential to induce landslide or activate landslides, depending on the nature and location of the work. MM Geology-3 would require qualified personnel to perform slope analyses prior to beginning exploratory work during the planning phase of work. Any temporary access road would need to comply with MM Geology-2. Implementation of these measures would reduce potential hazards related to landslides from exploratory work to less than significant levels. MITIGATION MEASURE MM Geology-3: Exploratory work proposals shall be reviewed by a qualified engineer or engineering geologist who will determine if the proposed work could cause slope instability. The potential to cause slope instability will depend on the nature and location of the exploratory work. The engineer and/or geologist may require a slope stability analysis to be performed. The analysis shall include considerations of long-term and construction-period stability for both static and dynamic conditions. Based on results of the study, a Slope Stabilization Plan shall be developed that will apply industry accepted engineering design and applications to stabilize any potentially unstable slopes in the exploratory work area and shall include measures for worker protection during construction activities. RESERVOIR DEWATERING Water would be released from the reservoir at higher flow rates than typical existing conditions during reservoir dewatering. Significant increases in flow rates have the potential to scour or erode downstream habitat; however, dewatering rates will typically be less than bankfull and not large enough to cause scour, or result in landslides along the stream channels. Rapid dewatering within a reservoir has the potential to cause landslides on the perimeter of the reservoirs. However, most District dams do not have sufficient outlet capacity to exceed safe dewatering rates; the exceptions to this are Anderson, Chesbro and Lexington dams. For these three dams and others, the District has June 2011 Page 3-227

280 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 studied geological conditions, collected data and will establish safe dewatering rates. At Anderson Reservoir, a guideline of 0.3 ft drawdown per day has already been established as a safe operating maximum. The analysis for safe dewatering parameters will be included in the development of reservoir dewatering plans, as prescribed under MM-General-3. The potential impact is less than significant Impact: Result in the Loss of Availability of a Known Mineral Resource That Would be of Value to the Locality or Region Mineral resources within the County include aggregate materials. Stevens Creek Quarry and Lexington Quarry are both located near reservoirs (Stevens Creek Reservoir and Lexington Reservoir, respectively). The DMP activities would occur within 0.25 miles of these mines; however, activities would only occur on existing District properties associated with the dams. The project activities would not have effects that could result in the loss of mineral resources. No additional resources are present within the project footprint areas and the project would not introduce new structures or activities that would prevent future mining in the County MITIGATION MEASURES MM Geology-1: Temporary access roads shall be recontoured and revegetated immediately after work requiring use of the roads is complete. Only native or non-invasive grasses shall be used to reclaim any temporary access road areas on dam faces. MM Geology-2: If a maintenance activity is to be performed, or temporary maintenance road must be installed, that includes cut into an adjacent steep slope (steeper than 2:1), slope stability shall be considered by a geosciences professional. Based on results of the study, a Slope Stabilization Plan shall be developed that will apply industry accepted engineering design and applications to stabilize any unstable slopes in the road work area and will include measures for worker protection during construction activities. MM Geology-3: Exploratory work proposals shall be reviewed by a qualified engineer or engineering geologist who will determine if the proposed work could cause slope instability. The potential to cause slope instability will depend on the nature and location of the exploratory work. The engineer and/or geologist may require a slope stability analysis to be performed. The analysis shall include considerations of long-term and construction-period stability for both static and dynamic conditions. Based on results of the study, a Slope Stabilization Plan shall be developed that will apply industry accepted engineering design and applications to stabilize any potentially unstable slopes in the exploratory work area and shall include measures for worker protection during construction activities. MM General 3: (previously listed in Section 3.3 Wildlife) June 2011 Page 3-228

281 Section 3.7 Geology, Soils, and Mineral Resources CHAPTER 3 Residual Impacts After Mitigation All impacts would be reduced to less than significant levels with implementation of the mitigation described here. Best Management Practices See the Mitigation Monitoring and Reporting Program (Appendix V) for complete text of BMPs WQ-41: Prevent Stormwater Pollution June 2011 Page 3-229

282 Section 3.8 Noise CHAPTER NOISE ENVIRONMENTAL SETTING Fundamental Concepts of Environmental Acoustics Noise is defined as unwanted sound. Sound is a rapid fluctuation of air pressure above and below atmospheric pressure. Sound levels are measured and expressed in decibels (db) with 0 db corresponding roughly to the threshold of hearing. Technical noise terms are given in Table Terms Decibel, db A-Weighted Sound Level, dba Community Noise Equivalent Level, CNEL Day/Night Noise Level, DNL Ambient Noise Level Intrusive SOURCE: Caltrans 1998 Table 3.8-1: Definition of Acoustical Terms Used in This Report Definitions A unit describing the amplitude of sound, equal to 20 times the logarithm to the base 10 of the ratio of the pressure of the sound measured to the reference pressure. The reference pressure for air is 20. The sound pressure level in decibels as measured on a sound level meter using the A-weighting filter network. The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the frequency response of the human ear and correlates well with subjective reactions to noise. The average A-weighted noise level during a 24-hour day, obtained after addition of 5 decibels in the evening from 7:00 pm to 10:00 pm and after addition of 10 decibels to sound levels in the night between 10:00 pm and 7:00 am. The average A-weighted noise level during a 24-hour day, obtained after addition of 10 decibels to levels measured in the night between 10:00 pm and 7:00 am. The composite of noise from all sources near and far. The normal or existing level of environmental noise at a given location. Noise that intrudes above the existing ambient noise at a given location. The relative intrusiveness of a sound depends upon its amplitude, duration, frequency, and time of occurrence as well as the prevailing ambient noise level. Most of the sounds that we hear do not consist of a single frequency, but rather a broad band with each frequency differing in sound level. The intensities of each frequency combine to generate a sound. Noise level is quantified by evaluating all of the frequencies of a sound with a filter that reflects the fact that human hearing is less sensitive at low and extreme high frequencies than mid-range frequencies. This is called A weighting, and the decibel level measured is called the A-weighted sound level (dba). Sound level is measured using a meter that includes an electrical filter corresponding to the A-weighting curve. Typical A-weighted noise levels measured in the environment and in industry are shown in Table June 2011 Page 3-230

283 Section 3.8 Noise CHAPTER 3 Table 3.8-2: Typical Noise Levels in the Environment SOURCE: Caltrans 1998 June 2011 Page 3-231

284 Section 3.8 Noise CHAPTER 3 Although the A-weighted noise level may adequately indicate the level of environmental noise at any instant in time, community noise levels vary continuously. Most environmental noise includes a conglomeration of noise from distant sources, which create a relatively steady background noise in which no particular source is identifiable. In determining the daily level of environmental noise, it is important to account for the difference in response of people to daytime and nighttime noises. Exterior background noises are generally lower during the nighttime than during the daytime. Most household noise also decreases at night and exterior noise becomes very noticeable despite reduced noise level. Most people sleep at night and become more sensitive to noise intrusion during evening hours. To account for human sensitivity to nighttime noise levels, a descriptor, L dn (day/night average sound level), was developed. The L dn divides the 24-hour day into the daytime of 7:00 a.m. to 10:00 p.m. and the nighttime of 10:00 p.m. to 7:00 a.m. The nighttime noise level is weighted 10 db higher than the daytime noise level. In general, a change in sound level of 1 dba cannot be perceived, a change of 3 dba is just noticeable, and a change at least 5 dba is required before any noticeable change in community response would be expected. A 10 dba increase in sound level is heard as approximately a doubling in loudness, and would likely cause an adverse change in community response. Noise impacts differ based on the ambient noise levels, proximity to the sound, the intensity and duration of the sound, and the time of day the sound occurs. Table outlines recommended maximum interior noise levels for intermittent noise, as outlined in the Santa Clara County General Plan (1994). Table 3.8-3: Recommended Maximum Interior Noise Levels for Intermittent Noise Use dba Residential 45 Commercial Hotel-Motel 45 Executive Offices, Conference Rooms 55 Staff Offices, Restaurant, Markets, Retail Stores 60 Sales, Secretarial 65 Sports Arena, Bowling Alley, etc. 75 Industrial Offices (same as above) Laboratory 60 Machine Shop, Assembly, Mineral Extraction 75 Public or Semi-Public Facility Concert Hall & Legitimate Theater 30 Auditorium, Movie Theater & Church 45 Hospital, Nursing Home & Firehouse (sleeping quarters) 45 School Classroom, Library 50 Other Public Buildings 55 SOURCE: Santa Clara County 1994 June 2011 Page 3-232

285 Section 3.8 Noise CHAPTER Noise Levels BACKGROUND NOISE SOURCES Background noise levels in the project area vary from low to moderate. The dams and facilities are primarily located in rural areas where noise levels are generally low (below 45 dba). Only the Rinconada Treated Water Reservoir Dam, Vasona Dam, and Coyote Percolation Ponds Dam are located in suburban areas. Suburban areas typically have about a 5 dba higher ambient noise level than rural areas (Engineers Toolbox 2005). Daytime suburban noise levels are generally 50 to 60 dba (Caltrans 1998). Lenihan Dam (at Lexington Reservoir) is located directly adjacent to Highway 17. The primary noise source in the vicinity of Lenihan Dam is traffic moving along Highway 17. A noise study completed for the Santa Clara County General Plan Update developed noise contour impacts for lands adjacent to major highways in the County. The northwestern corner of Lexington Reservoir (which includes the majority of Lenihan Dam) was mapped within the L dn contour of 55 to 60 dba. Vasona Dam is also located 500 feet from Highway 17. The Town of Los Gatos has created a noise contours map and shows the dam to be outside of the L dn contour, which is the lowest contour on the map (Town of Los Gatos 2000). Rinconada Treated Water Reservoir Dam and Vasona Dam are in suburban areas. Coyote Percolation Ponds Dam is approximately 0.25 miles from Interstate 101. The remaining dams are located in rural areas, where there are fewer noise sources. Noise sources for all of the dams include local traffic and nearby residential and recreational activities. SENSITIVE RECEPTORS Sensitive receptors typically include schools, hospitals, residences, or other land uses or activities easily affected by higher than average noise levels. Some sites have residences located near the dams and appurtenant structures which would be sensitive receptors. Recreationalists could also be sensitive receptors in the areas near the dams. Table lists the sensitive receptors likely at each dam. CONSTRUCTION EQUIPMENT A variety of power equipment is used by the District in dam maintenance. Noise generation from typical types of equipment likely to be used is shown in Table June 2011 Page 3-233

286 Section 3.8 Noise CHAPTER 3 Table 3.8-4: Sensitive Receptors Near District Dams Dam Sensitive Receptors Distance to Dam Almaden Dam Residences Approximately 2,000 feet Recreational users (hiking, fishing) Adjacent to the dam Anderson Dam Residences Approximately 300 feet Recreational users (fishing, boating) Adjacent to the dam Calero Main Dam Residences Approximately 1,500 feet Recreational users at the reservoir Adjacent to the dam Calero Auxiliary Dam Residences Approximately 800 feet Recreational users at the reservoir Adjacent to the dam Chesbro Dam Residences Approximately 400 feet Recreational users Adjacent to the dam Coyote Dam Recreational users (fishing, hiking) Adjacent to the dam Coyote Percolation Residences Approximately 200 feet Ponds Dam Recreational users (hikers, walkers) Adjacent to the dam Fellows Dike Historic Bailey-Fellows House Approximately 100 feet Guadalupe Dam Residences Approximately 800 feet Recreational users Adjacent to the dam Lenihan Dam Residences Over 1,000 feet Recreational users at Lexington Reservoir Adjacent to the dam County Park, St. Joseph s Hill Open Space Preserve, and along the Los Gatos Creek Trail Rinconada Treated Residences Approximately 150 feet Water Reservoir Dam Stevens Creek Dam Recreational users (fishing, hiking, kayaking) Adjacent to the dam Uvas Dam Residences Approximately 90 feet Recreational users Adjacent to the dam Vasona Dam Residences Approximately 20 feet Recreational Users Adjacent to the dam SOURCE: Google Maps 2006 June 2011 Page 3-234

287 Section 3.8 Noise CHAPTER 3 Equipment Table 3.8-5: Dam Maintenance Equipment Noise Generation Levels by Equipment and Activity Noise at 50 feet (in dba) Lawn mower 84 Vegetation control Chain saw 84 Vegetation control Trimmers/edgers/brush cutters Compactor (ground) Vegetation control Activity Burrowing rodent control, exploration, repair, erosion control Air Compressor 78 Activities utilizing pneumatic tools Backhoe 78 Exploration, bank hardening, sediment removal Concrete/Grout Pump 81 Concrete repair Concrete Vibrator 70 Concrete repair, filling rodent burrows Jackhammer 89 Exploration, Concrete repair Crane 81 Concrete repair, exploration, setting and removal panels for radial gate exercising Dozer 82 Road maintenance, embankment repairs Generator 73 Most mechanical activities, pump bypass Loader 80 Exploration, concrete repair, sediment removal, road repair, embankment repairs Paver 77 Road repair, concrete repair Pile Driver 80 Road repair Pneumatic Tools 85 Most mechanical activities Water Pump 71 Activities requiring pump over Power Hand Saw 70 Vegetation management Shovel 80 Exploration, concrete repair, sediment removal Trucks 83 Most activities Drill Rig 79 Exploration, seepage grouting Ventilation fan 79 Outlet pipe inspections SOURCE: Bolt et al. 1971; Pathak et al. 1989; FHA REGULATORY SETTING Federal and State There are no federal regulations related to noise applicable to the DMP Regional and Local Acceptable noise levels are regulated at the local level through the general plan and city and county noise ordinances. Santa Clara County, the City of San Jose, and the Town of Los Gatos, the jurisdictions in which the District s dams are located, have policies and ordinances that attempt to minimize the effects of noise through construction standards, zoning restrictions, and hours of operation. These policies are listed in Table June 2011 Page 3-235

288 Section 3.8 Noise CHAPTER 3 Table 3.8-6: Noise Regulations, Policies and Guidelines by Jurisdiction and Dam Jurisdiction Regulations Applicable Dams Santa Clara County City of San Jose Town of Los Gatos Santa Clara County Ordinance Code Section B through 158: The County Noise & Vibration Ordinance prohibits the operation of any tools or equipment used in construction, drilling, repair, or demolition work between weekdays and Saturday hours of 7:00 p.m. and 7:00 a.m., or at any time on Sundays or holidays, such that the sound creates a noise disturbance across a residential or commercial real property line, except for emergency work of public service utilities or by variance. Where technically and economically feasible, construction activities shall be conducted in such a manner that the maximum noise levels at affected properties will not exceed those listed below (B11-154, 6[b]): Mobile Equipment (intermittent, short-term operation) Daily, except Sun. and legal Holidays 7:00am to 7:00 pm Daily 7:00 pm to 7:00 am and all day Sun. and legal holidays Single- and Two-Family Dwelling Residential Areas Multi-family Dwelling Residential Areas Commerc ial Area 75 dba 80 dba 85 dba 50 dba 55 dba 60 dba Stationary Equipment (repetitively scheduled, relatively long-term operations) Daily, except Sun. and legal Holidays 7:00am to 7:00 pm 60 dba 65 dba 70 dba Daily 7:00 pm to 7:00 am and all day Sun. and legal holidays 50 dba 55 dba 60 dba The ordinance (at B11-154, 7) also prohibits operating any device that creates a vibrating or quivering effect that endangers or injures the safety or health of human beings or animals; or annoys or disturbs a person of normal sensitivities; or endangers or injures personal or real properties. San Jose 2020 General Plan (Chapter 4: Noise Element): According to the City of San Jose s noise and land use compatibility guidelines, the City s noise level objectives are 55 DNL for long-range exterior noise, 60 DNL as the short-range exterior noise level, and the maximum exterior noise level necessary to avoid significant adverse health effects is 76 DNL. The legal hours of construction within 500 feet of a residential unit are limited to the hours of 7:00 a.m. to 7:00 p.m. on Monday through Friday. Work outside this timeframe would require an exception. Town of Los Gatos Municipal Code (Sec ): The Los Gatos Municipal Code Section states that construction activities are allowed between 8:00 a.m. and 8:00 p.m. on weekdays and between 9:00 a.m. and 7:00 p.m. on weekends and holidays. No individual piece of equipment shall produce a noise level exceeding 85 dba at 25 feet. SOURCE: Santa Clara County, City of San Jose, and Town of Los Gatos, as stated in table Almaden, part of Anderson Dam (the City line is along the dam face), Calero, Chesbro, Coyote, Guadalupe, Lenihan, Stevens Creek, and Uvas dams Part of Anderson Dam and Coyote Percolation Ponds Dam Rinconada Treated Water Reservoir Dam, Vasona Dam June 2011 Page 3-236

289 Section 3.8 Noise CHAPTER SIGNIFICANCE CRITERIA The project would have significant noise effects on sensitive receptors if it would: Generate noise in excess of standards or that is disturbing to sensitive receptors such as nearby residences, Result in substantial permanent increase in the ambient noise level, or Expose persons to or generate excessive, continuous ground borne vibration IMPACTS AND MITIGATION Impact: Generate Noise in Excess of Standards or That is Disturbing to Sensitive Receptors Such as Nearby Residences OVERVIEW Noise effects are influenced by the level and duration of the noise, and the distance to the nearest sensitive receptor. For the purposes of the DMP, noise levels above 75 dba at an adjoining residential property line are considered significant for short term construction (maintenance) noise with Santa Clara County and the City of San Jose. This level matches the noise limit for temporary construction in the County Noise Ordinance, which is the more restrictive of these two jurisdictions. For the Rinconada Treated Water Reservoir and Vasona dams in the Town of Los Gatos, this noise standard is also applied along with the restriction on operating equipment that produces noise exceeding 85 dba at 25 feet. The noisiest piece of equipment likely to be used in the DMP is 86 dba at 50 feet according to Table Sound level decreases 6 dba for each doubling of distance (Pathak et al. 1989). Therefore at 200 feet the noise level would decrease to 74 dba. Any activity greater than 200 feet from the nearest adjacent property line would consistent with the County noise standard, and be considered less than significant. Use of the nosiest pieces of equipment would not meet the Town of Los Gatos noise standard of 85 dba at 25 feet. Noise generated from dam maintenance activities would generally occur during work hours (7:00 am to 7 pm in Santa Clara County and City of San Jose and 8:00 am to 8 pm in the Town of Los Gatos). All equipment and vehicles would be equipped with mufflers and would be operated according to manufacturer s recommendations consistent with District BMPs. The dams are in most cases located a sufficient distance from sensitive receptors to avoid significant effects. The District would implement BMPs at dams in within 1,000 feet of residences or other sensitive receptors to ensure noise disturbances are minimized. All noise impacts from DMP activities would be intermittent, generally lasting no more than a few weeks, and would often last only a few hours to a few days. Where noise levels may reach potentially significant levels, the District will implement mitigation measures as discussed. June 2011 Page 3-237

290 Section 3.8 Noise CHAPTER 3 SURFACES AND/OR EARTHWORK Surfaces work includes vegetation management, burrowing rodent control, road maintenance, erosion control and bank stabilization, embankment repair, and trash or debris removal. Surface work equipment would not be used for more than a few days at a time at any dam. Vegetation management would require the use of equipment such as flail mowers and lawn mowers, cutters, trimmers, and chain saws for the removal of trees. Some equipment may be necessary for compaction of rodent holes after rodent extermination. Equipment such as a hand or gas powered wackers would be used for compaction. District BMPs require the use of appropriate mufflers, therefore noise from these activities would range from 84 to 86 dba. If shooting is used as a method to control ground squirrels, trained professionals would use either air guns or rifles with silencers to minimize noise. Shooting is not expected to result in excessive noise to adjoining uses. Erosion control, bank stabilization, embankment repair, road maintenance, and boat ramp maintenance would involve trucks, loaders, dozers, compactors, backhoes, and other equipment. Noise from construction and heavy equipment used for these activities would be no more than 83 dba at 50 feet from the source of the noise. To minimize noise disturbances the District will implement BMP NO-2 (Minimize Disturbances to Residential Neighborhoods Due to Noise) for activities within 1,000 feet of residential uses. The maximum noise generated for surface work would be 86 dba at 50 feet from the source of the noise, with standard muffling controls were in place (Pathak et al. 1989). Noise would attenuate to acceptable levels (below 75 dba) before reaching sensitive receptors at most dams, except Uvas, Coyote Percolation Ponds, Rinconada Treated Water Reservoir, and Vasona dams, where residents are located within 200 feet from the dams. Some maintenance activities may generate noise that could be considered a significant impact to nearby residences and may not comply with local ordinances. At Uvas, Coyote Percolation Ponds, Rinconada Treated Water Reservoir, and Vasona dams, the District will implement MM Noise-1. This measure would require the District to measure noise levels at nearby residential properties and to take actions such as using alternative equipment or providing sound shielding if noise levels are above 75 dba. To comply with the Town of Los Gatos restriction on equipment that generates more than 85 dba at 25 feet, the District would implement MM Noise-2 at Rinconada Treated Water Reservoir and Vasona dams. MITIGATION MEASURE MM Noise-1: At Uvas, Coyote Percolation Ponds, Rinconada Treated Water Reservoir, and Vasona dams the District shall conduct regular noise monitoring during maintenance activities that may create noise levels greater than 75 dba at an adjacent residential property line. If the noise level is greater than 75 dba at a residential property line, the equipment generating the noise will be stopped and the District shall take action to reduce the noise level to less than 75 dba, prior to restarting work. Actions may include using special mufflers, June 2011 Page 3-238

291 Section 3.8 Noise CHAPTER 3 alternative equipment, or construction of temporary enclosures or noise barriers around activities. MM Noise-2: The District shall not utilize any piece of equipment that exceeds 85 dba at 25 feet while conducting DMP activities around the Rinconada Treated Water Reservoir and Vasona dams. Equipment shall be tested to ensure it complies with this noise standard prior to use. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures could require heavy equipment for tasks such as repairing the inlet/outlet, concrete demolition (such as a block house, spillway, dam face, etc) and construction, removal of sediment around the inlet structure, installation of seepage monitoring systems, etc. Noise generation of various types of equipment used in maintenance of dam appurtenances is shown in Table (concrete truck, concrete vibrator, jack hammer, truck crane, air compressor, generator, loader, etc.). A jack hammer can generate noise up to 91 dba at 50 feet. Sensitive receptors are close enough to the dams to potentially be significantly impacted by noise at Uvas Dam, Coyote Percolation Ponds, Rinconada Treated Water Reservoir Dam, and Vasona Dam. The District will implement MM Noise-1 and MM Noise-2 to reduce this impact to a less than significant level at these dams. Maintenance of appurtenant structures could require the use of diesel generators, which are stationary equipment that generate about 73 dba of noise at 50 feet. Impacts from generators would be less than significant. On rare occasions, it is possible that repair of an outlet or other asset would be deemed so urgent that work would be conducted around the clock. Also, when flow bypass is required under MM Wildlife-1, it would require the 24-hour use of a pump and generator. Under the County s Noise Ordinance, the maximum noise level between 7:00 p.m. and 7:00 a.m. is 50 dba. As noise level is reduced 6 dba for every doubling of distance, work requiring equipment that generates noise at 86 dba would not meet the night-time noise standard within 3,000 feet. A generator at 71 dba would not meet the night-time standard within 800 feet. The District would only work at night when absolutely necessary, and even if necessary would try to avoid using noisy equipment between 7:00 p.m. and 7:00 a.m. in Santa Clara County and the City of San Jose and 8:00 p.m. and 8:00 a.m. in the Town of Los Gatos. However, there is the possibility of maintenance activities generating noise in excess of the applicable noise standards, which is a potentially significant impact. The District would implement MM Noise-1 and MM Noise-2 to reduce noise levels to the greatest extend feasible for any night work. Even with the implementation of this mitigation measure, noise levels may still exceed 50 dba at nearby residences, which would be a significant unavoidable impact. June 2011 Page 3-239

292 Section 3.8 Noise CHAPTER 3 INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring do not require heavy equipment and would not generate significant noise. Inspections would last at most a few days and are typically performed by a small crew visually observing the surface or exercising gates and valves. Exploratory work would require construction equipment, boats, and barges and can range from drillings and borings to trenching for geotechnical investigation. Exploratory work can occur anywhere on or around the dams and even within the reservoir over the dams. Backhoes, drill rigs, crew trucks, compactors and other heavy equipment could be needed to perform exploratory work. Exploratory work equipment would generate noise levels up to 86 dba at 50 feet, which could result in significant impacts at Uvas Dam, Coyote Percolation Ponds, Rinconada Treated Water Reservoir Dam, and Vasona Dam. The work would occur infrequently and could last up to six months. MM Noise-1 and MM Noise-2 would be implemented for exploratory work at these dams to reduce this impact to a less than significant level. RESERVOIR DEWATERING Reservoir dewatering would not significantly change the existing noise environment. Water releases would occur over an extended time period and would not violate any established standards or guidelines. No noise impacts would occur from reservoir dewatering Impact: Result in Substantial Permanent Increase in the Ambient Noise Level Noise impacts from all maintenance activities would be temporary, generally lasting for hours or intermittently over a week. Inspections of outlet pipes could last several days. Maintenance of outlet pipes and tunnels could last several months. Some exploratory work may last up to six months, but this is still considered a temporary impact, with no permanent increase in noise levels. DMP activities would not cause permanent increases in ambient noise levels Impact: Expose Persons to Excessive, Continuous Ground-Borne Vibration OVERVIEW In addition to generating noise, heavy equipment can generate ground-borne vibration. Vibration is typically measured in peak particle velocity (PPV) in millimeters per second (mm/s). Generally, a PPV of less than 10 mm/s will not cause damage for intermittent vibration, such as from construction (maintenance) equipment (BSI 1994). For purposes of the DMP, vibrations that cause PPV greater than 10 mm/s is considered a significant impact. A paper by Flanagan (1993) titled, Ground vibrations from [tunnel boring machines] TBMs and shields in the journal Tunnels and Tunneling, includes a table of typical PPV intensities for construction equipment at varying distances as shown in Table June 2011 Page 3-240

293 Section 3.8 Noise CHAPTER 3 Table 3.8-7: Peak Particle Velocities at Defined Distances Equipment PPV in mm/s at feet from source 5 m (16.5 feet) 10 m (33 feet) 25 m (82.5 feet) Jack hammer Trucks Large bulldozer SOURCE: Flanagan 1993; Dowding 1996 Vehicles generate some vibration. Larger trucks and trucks that carry heavy equipment would generate more ground-borne vibration but it would be within the normal range that roads are equipped to handle. Maintenance activities could cause temporary ground-borne vibration, principally during road grading and repair, embankment repair, erosion control, breaking concrete for repair, or performing exploratory trenching or backhoe work. Equipment used may include wackers, compactors, trucks, graders, backhoes, and jack hammers. PPV associated with these activities would attenuate over a short distance and would not affect any structures or foundations. The effects of temporary vibration would not be significant. SURFACES AND/OR EARTHWORK Activities that involve compaction would have the highest potential for causing vibration. Compaction of filled burrows, compaction for embankment repair, erosion control, and compaction of gravel and dirt road surfaces using a wacker or compactor could cause vibration. Breaking of concrete for concrete structure repair may also cause some limited vibration. The vibration from equipment would attenuate to safe levels (less than 10 mm/s) within 16.5 feet, which is not within the proximity of any sensitive receptors. The dams are designed to handle PPV that could be generated from an earthquake. The Morgan Hill Earthquake of 1982 (magnitude 6.2) created PPV of over 100 mm/s at the Coyote Dam (Boore et al. 2004; Nuttli 1973); therefore, using a wacker or other equipment on the surface would not affect the dam face stability. There would be no significant effects from vibrations due to surfaces work. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures could involve the use of equipment such as trucks and jackhammers to break concrete (for concrete repairs). Removal of sediment would require a dump truck to remove the material, which could cause some vibration. Vibration from maintenance equipment would attenuate as shown in Table and would be less than 10 mm/s within 16.5 feet. Vibration would not affect any nearby houses or residents. The dams are designed to withstand earthquakes that would create PPV of approximately 100 mm/s (Boore et al. 2004), and would not be affected by vibration caused by heavy equipment on the dam. Several other appurtenant structure repairs, such as replacing caps on piezometers or maintaining piezometers and survey monuments, would not involve heavy equipment. These activities would not cause vibration. June 2011 Page 3-241

294 Section 3.8 Noise CHAPTER 3 INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring are mostly performed on foot and involve inspecting various pieces of equipment, surface conditions, and equipment functionality. Inspections and monitoring would not cause ground-borne vibration. Exploratory work could involve drilling or use of heavy equipment depending on the need of the exploratory work. The nature and method of exploratory work would be dictated by the need. Equipment for exploratory work could include backhoes, trenchers, dozers, trucks, compactors, and drill rigs. This equipment would create PPV similar to the equipment listed in Table and would not adversely affect the dams. All vibrational effects would attenuate rapidly with distance and would be less than 10 mm/s within 16.5 feet of the equipment. Vibration would not affect residents located nearby and would not significantly affect any recreationalists as work areas would be cordoned off to prevent accidents. RESERVOIR DEWATERING Reservoir dewatering would not result in discernible vibration. Water releases would be released in stages over an extended time period. No impacts would occur from lowering reservoir levels MITIGATION MEASURES MM Noise-1: At Uvas, Coyote Percolation Ponds, Rinconada Treated Water Reservoir, and Vasona dams the District shall conduct regular noise monitoring during maintenance activities that may create noise levels greater than 75 dba at an adjacent residential property line. If the noise level is greater than 75 dba at a residential property line, the equipment generating the noise will be stopped and the District shall take action to reduce the noise level to less than 75 dba, prior to restarting work. Actions may include using special mufflers, alternative equipment, or construction of temporary enclosures or noise barriers around activities. MM Noise-2: The District shall not utilize any piece of equipment that exceeds 85 dba at 25 feet while conducting DMP activities around the Rinconada Treated Water Reservoir and Vasona dams. Equipment shall be tested to ensure it complies with this noise standard prior to use. June 2011 Page 3-242

295 Section 3.8 Noise CHAPTER 3 Residual Impacts After Mitigation If maintenance activities need to be conducted around the clock (potentially for inlet/outlet repairs, or for running a generator and pump to provide flow bypass) noise may be generated at levels that exceed the San Jose and the County s Noise Ordinance for construction work (maintenance) between 7:00 p.m. and 7:00 a.m. (or 8:00 p.m. and 8:00 a.m. in the Town of Los Gatos) even with the implementation of mitigation measures discussed above. All other potential impacts would be reduced to less than significant level with the implementation of proposed mitigation measures. Best Management Practices (See Project Description or Appendix X for Complete Text of BMPs) NO-2: Minimize Disturbances to Residential Neighborhoods Due to Noise June 2011 Page 3-243

296 Section 3.9 Air Quality CHAPTER AIR QUALITY ENVIRONMENTAL SETTING Climate and Weather REGIONAL OVERVIEW The project region is bounded by the Santa Cruz Mountains to the west, the Diablo Range to the east, the San Francisco Bay to the north, and the convergence of the Gavilan Range and the Diablo Range to the south. Temperatures are warm in summer, under mostly clear skies, although nights are cool and there is a relatively large diurnal temperature range. Winter temperatures are mild, except for very cool, but generally frostless mornings (BAAQMD 2004a). The mean maximum temperatures in Santa Clara County range from the high 70s to the low 80s during the summer and from the high 50s to the low 60s during the winter. Mean minimum temperatures range from the high 50s during the summer to the low 40s during the winter. Temperature extremes are greater inland where the moderating effect of the Bay is not as strong. Rainfall amounts are modest, ranging from an average of about 15 inches in the Valley floor (San Jose) to 40 to 60 inches in the Santa Cruz Mountains (Santa Clara County 1994; BAAQMD 2004a). Area wind patterns are influenced greatly by the terrain, resulting in a prevailing flow roughly parallel to the Santa Clara Valley's northwest-southeast axis with a north-northwesterly sea breeze extending up the valley during the afternoon and early evening and a light south-southeasterly drainage flow occurring during the late evening and early morning (BAAQMD 2004a). AIR QUALITY All of the dams are located within the jurisdiction of the BAAQMD. The San Francisco Bay Area is in attainment for carbon monoxide (CO), oxides of nitrogen (NO x ), sulfur dioxide (SO 2 ), and lead (Pb). The area is in non-attainment for ozone (O 3 ), particulate matter under 10 microns in diameter (PM 10 ), and for particulate matter under 2.5 microns in diameter (PM 2.5 ) (BAAQMD 2010a). Table includes the state and federal standards for air quality. The Bay Area has seen significant reductions in PM 10 levels, with peak values down more than 30 percent since The values are greatly influenced by weather conditions, similar to ozone, and the degree of improvement depends upon the location and time interval examined. Although less particulate matter is emitted from tailpipes, more particulate matter is being entrained by motor vehicle tires as the total number of miles driven in the Bay Area increases (BAAQMD 2004b). June 2011 Page 3-244

297 Section 3.9 Air Quality CHAPTER 3 Table 3.9-1: State and Federal Air Quality Standards Pollutant Average Time CA CA Federal Standard Attainment Standards Ozone (O 3 ) 1 Hr ppm N 8 Hr ppm N ppm Carbon Monoxide (CO) 1 Hr ppm A 35.0 ppm 8 Hr. 9.0 ppm A 9.0 ppm Nitrogen Dioxide (NO x ) Annual ppm ppm 1 Hr ppm A ppm Sulfur Dioxide (SO x ) Annual 0.03 ppm 24 Hr ppm A 0.14 ppm 1 Hr ppm A Particulate Matter (PM 10 ) Annual 20 μg/m 3 N 24 Hr. 50 μg /m 3 N 150 μg /m 3 Federal Attainment N A A A U A A U (PM 2.5 ) Annual 12 μg/m 3 24 Hr. Lead (Pb) 30-day 1.5 μg /m 3 Calendar Quarter A= Attainment N=Non-attainment U=Unclassified (data is incomplete) SOURCE: BAAQMD 2010a GLOBAL CLIMATE CHANGE N 15 μg/m 3 35 μg/m 3 A A N 1.5 μg /m 3 A Global climate change refers to changes in weather including temperatures, precipitation, and wind patterns. Global temperatures are modulated by naturally occurring and anthropogenic-generated (generated by mankind) atmospheric gases such as carbon dioxide, methane, and nitrous oxide. These gases allow sunlight into the Earth s atmosphere but prevent heat from radiating back out into outer space and escaping from the earth s atmosphere, thus altering the Earth s energy balance. This phenomenon is known as the greenhouse effect. Based on scientific understanding, global climate may already be changing as a result of human activities over a long period of time. No single project is likely to independently create or arrest climate change. However, individual projects have the potential to contribute to climate change or to exacerbate its effects on the environment. As such the analysis of greenhouse gas emissions and potential impacts to global climate change is included in the discussion of cumulative impacts in Chapter REGULATORY SETTING Federal CLEAN AIR ACT The Clean Air Act requires the US EPA to identify ambient air quality standards to protect public health and welfare. Pursuant to the Clean Air Act, the US EPA has classified air basins (i.e., distinct geographic regions) as either attainment or non-attainment for each criteria pollutant, based on whether or not the federal June 2011 Page 3-245

298 Section 3.9 Air Quality CHAPTER 3 ambient air quality standards have been achieved. National air quality standards are set at levels determined to be protective of public health with an adequate safety margin. Some air basins have not received sufficient analysis for certain criteria air pollutants and are designated as unclassified for those pollutants. The Bay Area has been designated as attainment for CO, NO X, SO 2, and Pb; non-attainment for O 3 and PM 2.5 ; and unclassified for PM 10 at the federal level (BAAQMD 2010a) State CALIFORNIA CLEAN AIR ACT The California Air Resources Board (CARB) is the state agency responsible for regulating mobile source (vehicle) emissions and overseeing the activities of local air pollution control districts. CARB established state ambient air quality standards for the above listed federal-regulated pollutants. The state standards are generally more stringent than the federal standards. Under the California Clean Air Act, areas have been designated as attainment or non-attainment with respect to state ambient air quality standards. At the state level, the Bay Area has been designated as attainment for CO, NO X, SO 2, and Pb and as non-attainment for O 3, PM 2.5, and PM 10 (BAAQMD 2010a). GLOBAL WARMING SOLUTIONS ACT California Assembly Bill 32 (AB 32), the Global Warming Solutions Act of 2006, was enacted as legislation in The bill requires achievement by 2020 of a statewide greenhouse gas emissions limit equivalent to 1990 emissions, and the adoption of rules and regulations to achieve the maximum technologically feasible and cost-effective greenhouse gas emissions reductions. This bill is based on Executive Order S-3-05, announced by California Governor Arnold Schwarzenegger on June 1, S-3-05 set emissions reduction targets as follows: by 2010 reduce green house gas emissions to 2000 levels; by 2020 reduce green house gas emissions to 1990 levels; by 2050 reduce green house gas emissions to 80 percent below 1990 levels (OTG 2005). Emissions strategies for reduction of greenhouse gases have been presented in the California Climate Action Team s Report to the Governor. The report proposes a path to achieve the green house gas reduction targets found in AB 32 and Executive Order S Regional and Local The dams are located in the San Francisco Bay Area Air Basin, which is under the jurisdiction of the BAAQMD. BAAQMD regulates air quality through its permit authority over most types of stationary emission sources and through its planning and review activities. BAAQMD no longer monitors for Pb in the air basin due to extremely low levels, and has ceased monitoring for SO 2 at selected monitoring stations in the air basin for the same reason. Pursuant to the California Clean Air Act, the BAAQMD developed the Clean Air Plan (CAP) to reduce emission of certain air pollutants that lead to the formation of ozone. The June 2011 Page 3-246

299 Section 3.9 Air Quality CHAPTER CAP was approved in September 2010, and is a multi-pollutant plan to protect public health and the climate. The CAP outlines a control strategy review to ensure that the CAP continues to include all feasible measures to reduce ozone, an update of the BAAQMD's emission inventory, estimates of emission reductions achieved by the CAP, and an assessment of air quality trends. The 2010 CAP control strategy includes revised, updated, and new measures in the three traditional control measure categories: Stationary Source Measures, Mobile Source Measures, and Transportation Control Measures. In addition, the CAP identifies two new categories of control measures: Land Use and Local Impact Measures, and Energy and Climate Measures. The 2010 CAP: Updates the Bay Area 2005 Ozone Strategy in accordance with the requirements of the California Clean Air Act to implement all feasible measures to reduce ozone; Provides a control strategy to reduce ozone, particulate matter (PM), air toxics, and greenhouse gases in a single, integrated plan; Reviews progress in improving air quality in recent years; and Establishes emission control measures to be adopted or implemented in the timeframe (BAAQMD 2010b) SIGNIFICANCE CRITERIA The project would have significant effects to air quality if it would: Violate any applicable air quality standards or air quality plan or expose sensitive receptors to substantial pollutant concentrations, or Expose a substantial number of people to objectionable odors IMPACTS AND MITIGATION Impact: Violate Any Applicable Air Quality Standards or Air Quality Plan or to Expose Sensitive Receptors to Substantial Pollutant Concentrations OVERVIEW DMP activities would not generate substantial pollutant concentrations that could violate air quality standards or affect sensitive receptors. Sensitive receptors include nearby residences and reservoir/park visitors. All types of maintenance activities would result in emissions from vehicle miles traveled to and from each site. Maintenance would also have emissions from activities on-site as are discussed below. The emissions of pollutants from maintenance activities would be below the thresholds listed in the San Francisco Bay Area CAP (BAAQMD 2010b) and would not contribute substantially to an existing or projected air quality violation, with the potential exception of long-term use of generators needed to pump water over the crest of the dam during specific maintenance activites as discussed below. June 2011 Page 3-247

300 Section 3.9 Air Quality CHAPTER 3 Emissions from DMP activities are considered construction emissions under the BAAQMD CEQA Guidelines. Table shows the average daily emissions of criteria air pollutants resulting from both vehicle travel and maintenance activities, compared to the BAAQMD thresholds. Calculations and assumptions used to estimate the emissions associated with the DMP can be found in Appendix X. The District implements BAAQMD dust control measures through BMP AQ-1. Table 3.9-2: Average Emissions From the DMP and BAAQMD Thresholds for Criteria Air Pollutants ROG (lbs/day) NO X (lbs/day) PM (lbs/day) CO 2 (metric tons/year) Average Daily DMP Emissions BAAQMD Adopted Air Quality Thresholds of Significance ,100 Significant? No No* No No Sources: BAAQMD 2010c, California Air Resources Board 2007, South Coast Air Quality Management District 2011, URBEMIS 2007 *As discussed below, the long-term use of generators during specific maintenance activites may result in an exceedance of NOx standards. SURFACES AND/OR EARTHWORK VEGETATION MANAGEMENT Vegetation management would result in some particulate matter emissions for surface disturbance and use of tools and equipment. Activities include vegetation trimming and tree removal. Tree removal is proposed at Almaden Dam and Vasona Dam, and may be necessary elsewhere at program sites. The removal of mature trees would require minor excavation of less than 10 cubic yards of soil and use of some gas-fired power tools, including chain saws. Tree removal is expected to be a one-time activity after initiating the project. After completion of the initial treeremoval as required to protect the dams, proper vegetation maintenance will prevent further development of woody growth on dam faces. Surface vegetation maintenance may require the use of lawn mowers and/or flail mowers. Most small engines (such as those in lawn mowers, trimmers, and chain saws) emit pollutants. The District would use non-road engine equipment such as mowers for up to 70 hours per month for 3 to 4 months per year. Equipment would not be used for more than 8 hours a day at any one location. As shown in Table total DMP emissions would not exceed BAAQMD standards. Emissions are considerably below thresholds and would therefore not expose sensitive receptors to substantial pollutant concentrations. June 2011 Page 3-248

301 Section 3.9 Air Quality CHAPTER 3 The District may utilize controlled burns as a vegetation management method (refer to the Project Description). To utilize controlled burns as a vegetation management method it would be first need to be authorized by the BAAQMD and the Santa Clara County Fire Department. Controlled burns would only be conducted on certain declared days, when the air quality is higher. The Air Basin Plan incorporates permits for prescribed burning. Given the rare occasions that controlled burning would occur (at most once per site per year), the limited duration of occurrence (a few hours to one work day), and the amount of area to be burned (approximately an acre), impacts to air quality would be less than significant. Herbicide application uses water as a carrier and the potential for volatile organic gas emissions is minimal. The herbicides used for vegetation management are not hazardous air contaminants when used in accordance with state law. Trails located within 20 feet of areas being sprayed with herbicides would be temporarily closed to public access and signed, per BMP HM-4. Herbicides would not be sprayed if winds are greater than 10 miles per hour consistent with labeling requirements and District policy. Potential effects to air quality from herbicide application are less than significant level. BURROWING RODENT CONTROL Burrowing rodent control includes poison bait, shooting, fumigants, kill traps, and live traps. The only method of burrowing rodent control that would have non-travel related air emissions is fumigants. Two types of fumigants may be used: gas cartridge and aluminum phosphide. When a gas cartridge is ignited, it produces CO gas that fills the burrow system. The CO induces a loss of consciousness and death in the animal. Aluminum phosphide comes in pellet form. Aluminum phosphide works by reacting with the moisture in the soil and the atmosphere to produce a lethal phosphine gas that is toxic to all mammals. This gas is colorless and heavier than air with a pungent odor. Fumigants are only used during the springtime when the moisture of the soil facilitates soil cohesion and no fumigant is lost out of cracks in the soil. Fumigants are applied directly into burrows and the burrows are sealed to minimize gasses (carbon monoxide or phosphine) that escape into the atmosphere. Carbon monoxide emissions would be little to none because they would remain underground and would not violate any air quality standards for emissions. Phosphine is not a criteria pollutant and does not have emissions standards; however, aluminum phosphide would be handled according to use permits issued by the County Agricultural Commissioner. Phosphine gas is heavier than air and therefore would remain underground in burrows and would not escape into the atmosphere. Potential impacts from fumigants are less than significant. EROSION CONTROL, BANK STABILIZATION, AND EMBANKMENT REPAIR Other surfaces work includes installing erosion control and bank stabilization features within plunge pools and stilling basins at the base of the outlets. June 2011 Page 3-249

302 Section 3.9 Air Quality CHAPTER 3 Embankment repair could be required to repair slumps anywhere on the dam face, cracks on the dam and at the abutments after seismic events, or landslides caused by severe erosion. Correcting erosion could also occur anywhere on or around the dams. These activities would require earthmoving, such as excavation and placement of fill. Erosion control and bank stabilization is generally performed during the summer months (April through October) when soils are dry, which could lead to fugitive particulate matter emissions. The BAAQMD significance criteria for earthmoving activities emphasize implementation of effective and comprehensive dust control measures. The District implements these standard fugitive dust suppression measures as described in BMP AQ-1. The potential impact from dust generation from erosion control and bank stabilization is less than significant. Maintenance activities also require construction equipment to complete erosion control tasks. Mobile sources (such as construction vehicles) and stationary sources (such as fuel-powered electrical generators) would contribute to localized CO emissions, reactive organic gases (ROG), and NO x emissions. ROG and NO x lead to the formation of ozone, or smog, in the lower atmosphere. These activities are short in duration and require relatively few vehicles and pieces of equipment. The potential impact to air quality is less than significant as shown in Table ROAD AND BOAT RAMP MAINTENANCE Access road repair could vary from filling potholes to grading and road reconstruction. Emissions would include fugitive dust emissions from grading unpaved surfaces and vehicle emissions from vehicles such as dump trucks, loaders, graders, rollers, etc. Emissions would vary depending upon the size of the project; however, access road and boat ramp work are considered construction projects and the District would implement the BAAQMD construction measures through BMP AQ-1 to reduce potential dust effects. Many of the activities associated with surfaces and/or earthwork would have minimal potential to cause impacts. These activities would require few vehicles (often only one) and therefore would not generate excessive quantities of fugitive dust or other criteria pollutants from existing conditions. Air impacts from road and boat ramp maintenance would be less than significant as shown in Table MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of the inlet, inlet valves, hydraulic systems, etc. would require a few vehicles to perform the work (such as small loaders), which would be staged at the dam. Divers may be used for some inlet repairs. Using divers requires a boat and/or barge on the reservoir and air compressors. Emissions from this equipment would be limited because only a few pieces of equipment would be needed and only for a few hours at a time. June 2011 Page 3-250

303 Section 3.9 Air Quality CHAPTER 3 Flow bypass has been described in this document as a method of mitigating adverse impacts from altering downstream flows (MM Wildlife-1). Flow bypass requires the use of generator and pump to pump water from the reservoir, over the dam, and into the downstream channel when water cannot travel through the inlet/outlet valves (because it/they are closed). A typical standby diesel generator produces pounds of NO x per megawatt hour of power generated (SBCAPCD 2007). A diesel generator may be required to run for 24 hours a day during flow bypass. Emissions from such a generator could exceed the 54 pounds per day limit set by BAAQMD, which is a potentially significant impact. MM Air Quality-1 would require the use of diesel generators with emission controls that will limit the emissions of ROG, NO x and PM 2.5 to 54 pounds per day and PM 10 to 82 pounds per day. Work may also include removal of sediment around the inlet or hydraulic system. Sediment gradually accumulates over the years near the inlet structure and requires the removal of up to 10 cubic yards of sediment to restore functionality at the inlet. Sediments would be stockpiled at a designated disturbed location along the dam crest, parking area, or staging area. Sediments would be covered after drying to prevent fugitive dust. Sediment removal would likely only occur once at each dam location in a 10-year time period. Sediments would be removed by a large hauling truck to an appropriate destination. Not more than one truckload of material is expected and the emissions from one truck would not result in significant air quality impacts. Activities such as concrete structure repair could require transport of soil for fill and demolition of concrete that could generate considerable fugitive dust. Where DMP activities would require stockpiles of soil or require demolition of structures, BMP AQ-1, which includes dust control methods from BAAQMD would be utilized. Maintenance of other appurtenant structures and equipment would use small quantities of various emission-producing materials, such as primer, NSF International-approved paint, and epoxy resins for carbon fiber application. Although the physical and chemical properties of the products and their constituents have not been verified, they are required to comply with California emission standards and the anticipated minimal use of the above-mentioned products would not be expected to exceed the significance criteria for toxic air contaminants established by BAAQMD. Impacts from concrete structure repair would be less than significant. MITIGATION MEASURE MM Air Quality-1: Any activity that requires running a diesel generator for 24 hours or more must use a generator manufactured since January 1996 that is certified to meet US EPA and CARB Tier 1 Emission Standards, and must be equipped with an exhaust particulate filter system or other emission controls to limit the emission of ROG, NO x and PM 2.5 to 54 pounds per day and PM 10 to 82 pounds per day. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Formal inspections occur annually, semi-annually, and quarterly; however, informal inspections occur on an on-going basis. Inspections involve passenger (inspection team) vehicle transport to the dam and a walking tour of dam facilities. Air emissions June 2011 Page 3-251

304 Section 3.9 Air Quality CHAPTER 3 are limited to a few passenger vehicles traveling to and from the dam sites, which would be insignificant. Exploratory trenching, drilling, backhoe work, etc. would require approximately vehicles for periods of up to several weeks. Temporary access roads may also need to be constructed during exploratory work. Emissions from vehicles and from graded or denuded surfaces may occur. Heavy equipment would remain at the construction (maintenance) site to reduce emissions from vehicle trips. Inspection and monitoring activities would require few daily trips (often only one to two passenger vehicles) and therefore would not generate excessive quantities of fugitive dust or other criteria pollutants. BMP AQ-1 implements BAAQMD dust control measures to minimize fugitive dust emissions. Emissions would be less than significant during any exploratory work that involves ground disturbance as shown in Table RESERVOIR DEWATERING Reservoir drawdown could result in the exposure of previously inundated land to air and wind, encouraging erosion and the release of fugitive dust. The severity of air quality impacts would be dependent on the extent of the drawdown, the type and amount of soil exposed, and the prevailing atmospheric conditions (level of precipitation, humidity, and wind) during the period of exposure. Surface disturbance is not required for reservoir drawdown which would reduce the potential for fugitive dust in excess of air quality standards or to contribute to air quality violations. Reservoir dewatering may also require a flow bypass system to retain downstream flows to the greatest extent feasible. If a diesel generator is needed for flow bypass the District would implement MM Air Quality-1 to ensure that the generator does not exceed BAAQMD emission thresholds Impact: Expose a Substantial Number of People to Objectionable Odors OVERVIEW Most DMP activities would not generate odors. Some odors may result from stockpiled sediments (that may contain organic matter), vehicle emissions, rodent carcasses, and reservoir drawdown. With these activities adjacent residences of the dams and park visitors can potentially be impacted by odor impacts. Potential sensitive odor receptors in the vicinity of District maintenance projects could include recreationalists and nearby residents. Only Coyote Percolation Ponds Dam, Uvas, Vasona, Rinconada Treated Water Reservoir and Chesbro dams have residences within approximately 400 feet of the dam facilities. SURFACES AND/OR EARTHWORK Vegetation management could result in some short-term temporary odors during spraying of herbicides. Glyphosate is the District s primary herbicide of use, although this is subject to change in the future. Glyphosate is odorless; however, other herbicides used by the District currently and in the future may not be odorless. June 2011 Page 3-252

305 Section 3.9 Air Quality CHAPTER 3 Odiferous herbicides would only emit odors during application. Any trails adjacent to the dam faces or access roads would be signed according to BMP HM-4 and may be temporarily shut down in consultation with the Santa Clara County Parks and Recreation Department for a few hours (up to 12 hours) during application. Odors would not impact recreationalists due to intervening distance from the source. Houses located within 400 feet of Uvas, Chesbro, Rinconada Treated Water Reservoir and Vasona dams may be exposed to short-term temporary odors from herbicide use. Odors (if any) would only persist for up to a few hours. Burrowing rodent control would include the use of poison bait, fumigants, and live traps. Poison bait does not have odor. Fumigant gasses would be confined within underground burrows and would not emit odors. Rodent carcasses caught in kill traps could emit objectionable odors if left on the surface for several days, especially in the summer months. Collection of carcasses once a day would minimize any potential odors from decay. Odor emissions from vegetation and rodent control would be less than significant. Erosion control and bank hardening activities may include the excavation and removal of soils with high organic matter content in order to apply permanent bank hardening and stabilization structures (such as concrete sand bag riprap). Organic matter tends to accumulate in areas near stream channels where hardening or erosion control may be necessary. Erosion control and bank hardening work may require some stockpiling of material either for later removal or reuse. BMP AQ-4, which prohibits the stockpiling of odorous organic matter laden sediments, would ensure objectionable odors would not cause significant impacts to recreationalists or residents during erosion control and bank hardening activities. Access road work and boat ramp work would not emit odors other than diesel exhaust from heavy equipment. Any odors generated would be of limited duration. Odor emissions from roadwork would be less than significant. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Maintenance of appurtenant structures may include removal of sediments around the inlet structures and hydraulic systems. Wet sediments would then be stockpiled at the dam to dry before removal. Stored sediments would not have odors because no organic matter would be present in deep sediments such as those found around the inlet (due to unsuitable growth conditions such as light limitation). Organic matter growth is also unlikely because the flow of water through the inlet and out the outlet would be inhibitive to aquatic growth. The impact from stockpiling sediment removed from the inlet structures would be less than significant. Other maintenance activities, such as repairs to fences (temporary or permanent fencing), the inlet, concrete structures, inlet valves, hydraulic lines, outlet pipe, etc., would use small quantities of various emission-producing materials such as primer, NSF International-approved paint, and epoxy resins. The anticipated use of the above-mentioned products would be minimal and would not be expected to generate objectionable odors. Maintenance activities would occur near the dams and would be at least 20 feet from any residential property. Odors would be short in duration and would dissipate before being a nuisance to nearby receptors. June 2011 Page 3-253

306 Section 3.9 Air Quality CHAPTER 3 Workers could be exposed to objectionable or harmful odors but would use the proper personal protection equipment, including facemasks, etc., as required under worker safety to prevent significant impacts. Paint and other odors would be generally limited to the immediate work area and odors would only be strong for a period of a few days and would not affect significant numbers of sensitive receptors. The potential odor impact from maintenance of dam appurtenances is less than significant. INSPECTIONS, MONITORING, AND EXPLORATORY WORK Inspections and monitoring would not produce any odor-causing emissions. Exploratory drilling and backhoe work could expose soils that may contain organic matter with an odor. BMP AQ-4, which prohibits the stockpiling of odorous sediments, would ensure objectionable odors would not cause significant impacts during exploratory work. RESERVOIR DEWATERING Maintenance activities may require reservoir dewatering to provide DMP personnel access to the inlet, outlet, or other underwater structures in need of repair. Reservoir dewatering could expose portions of the reservoir bottom, which may be covered with organic matter. The exposure of benthic aquatic biota to air and sun would cause decomposition and could cause unpleasant odors. The characteristic smell would be a boggy or sulfuric smell from decomposition of organic matter. Potential odor impacts are not expected to be significant. Drawdown is not expected to completely drain the reservoirs, and uncovered areas would dry out quickly which will minimize potential odors MITIGATION MEASURES MM Air Quality-1: Any activity that requires running a diesel generator for 24 hours or more must use a generator manufactured since January 1996 that is certified to meet US EPA and CARB Tier 1 Emission Standards, and must be equipped with an exhaust particulate filter system or other emission controls to limit the emission of ROG, NO x and PM 2.5 to 54 pounds per day and PM 10 to 82 pounds per day. Residual Impacts After Mitigation All impacts would be reduced to less than significant levels with implementation of the mitigation described here. Best Management Practices (See Mitigation Monitoring and Reporting Program (Appendix V) for complete text of BMPs) AQ-1: Use Basic Dust Control Measures for All Construction Sites AQ-4: Avoid Stockpiling Potentially Odorous Materials June 2011 Page 3-254

307 Section 3.10 Traffic and Transportation CHAPTER TRAFFIC AND TRANSPORTATION ENVIRONMENTAL SETTING Transportation Infrastructure REGIONAL OVERVIEW Santa Clara County has a well-developed transportation network that includes interstate and state highways and surface streets ranging from regional arterials to local roads serving individual residential neighborhoods. Traffic congestion is most prominent in urban centers in and around the City of San Jose. Refer to Figure for a map of the major highways and roads in the project region. HIGHWAYS AND LOCAL ROADS Interstate and state highways pass near the dams where program activities could occur. The major highways near project dams include: US Route 101 State Highway 85 State Highway 17 Interstate Highway 280 State Highway 87 Most dams are crossed or accessed by a local road. All dams, with the exception of Vasona Dam and Rinconada Treated Water Reservoir Dam, are located in areas that support primarily open space or low-density residential communities. Traffic volume along roads on which the dams are located is low and is generally heaviest on weekends (for recreational travel). Vasona Dam and Rinconada Treated Water Reservoir Dam are located in more populated, low-density residential areas. Traffic volume on residential roads is low and consists primarily of local residents. Table lists the major highways and local roads that provide primary access to each dam. LEVEL OF SERVICE Level of Service (LOS) is a scale of values, with designations A through F, that describes degrees of street congestion, or interference with the normal free flow of traffic. LOS A indicates free traffic flow at design speed or the absence of congestion, while LOS F indicates a congested condition where traffic flow is seriously restricted and travel speeds are significantly below design speed. Level of service is sometimes expressed in terms of a street volume to capacity (v/c) ratio. Table identifies the ranges of LOS for signalized intersections and street segments. June 2011 Page 3-255

308 Figure : Major Highways and Roads in the Project Region June 2011 Page 3-256

309 Section 3.10 Traffic and Transportation CHAPTER 3 Table : Major Highways and Local Roads That Provide Access to Dams Dam Major Arterial Providing Access Local Access Roads Almaden Dam Almaden Expressway (at Camden) Alamitos Road Anderson Dam US Route 101 at Cochrane Road Cochrane Road Calero Main Dam US Route 101 at Bailey Ave McKean Road Calero Auxiliary Dam US Route 101 at Bailey Ave McKean Road Chesbro Dam US Route 101 at Cochrane Road Oak Glen Ave Coyote Dam US Route 101 at Masten Ave Roop Road Coyote Percolation Ponds Dam US Route 101 at State Highway 85 Monterey Road Fellows Dike US Route 101 at Bailey Ave McKean Road Guadalupe Dam Almaden Expressway at Camden Hicks Road Lenihan Dam State Highway 17 Alma Bridge Road Rinconada Treated Water State Highway 85 at Winchester Boulevard More Avenue Reservoir Dam Stevens Creek Dam Foothill Boulevard off I-280 Stephens Creek Road Uvas Dam US Route 101 at Tennant Road Uvas Road Vasona Dam State Highway 17 at Lark Road Lark Road SOURCE: The LOS along the highway segments that provide access to the dams is generally poor during peak hours. Figures and show congestion maps for the major highways in the South Bay. Table lists the peak directional traffic volumes and corresponding LOS for major highway segments that are listed as access points in Table Peak traffic hours in the Bay Area are between 6:00 a.m. and 9:00 a.m. for the morning commute and 3:00 p.m. and 7:00 p.m. in the afternoon commute. Weekend conditions on roads such as Highway 17, particularly in the summer, can also be poor. Traffic conditions improve considerably during off-peak hours (Caltrans 2007). The local streets providing access to the dams generally have a better level of service than local highways, since they lack numerous intersections and are used mostly for residential and recreational access. June 2011 Page 3-257

310 Figure : Northern Santa Clara County Average Daily Traffic (ADT) June 2011 Page 3-258

311 Figure : Southern Santa Clara County Average Daily Traffic (ADT) June 2011 Page 3-259

312 Section 3.10 Traffic and Transportation CHAPTER 3 Table : Signalized Street and Intersection LOS Criteria LOS Description Level Free flow operations. Vehicles are unimpeded in their ability to maneuver within the A traffic stream; stopped delay at intersections is minimal. Travel is within 70% of free flow operation. Vehicles are slightly restricted to B maneuver within the traffic stream; stopped delay at intersections is not bothersome to most drivers. Stable operations. The ability to maneuver is somewhat restricted. Some queuing C occurs at signalized intersections, however all vehicles clear the intersection on all or nearly all cycles. High-density traffic flows. Travel speeds as low as 40% of free flow operation. D Vehicles are restricted in their ability to maneuver within the traffic stream, and some vehicles may not clear an intersection within a single signal cycle on a regular basis. Operations at or near capacity. There is little freedom to maneuver, and driver frustration is high. Operations are unstable, with even minor disruptions resulting in E substantially increased delays. Failure of vehicles to clear an intersection in a single cycle is a regular occurrence. Forced breakdown flow. Traffic volume exceeds the capacity of the system. F Intersections often become the focal point for street system failure. Operations are characterized by extensive queues and long delays. 1 V/C is the Volume/Capacity ratio; ICU is the Intersection Capacity Utilization SOURCE: Transportation Research Board 2000 V/C or ICU >1.00 Table : Peak Directional Traffic Volumes and Corresponding LOS for Major Highway Segments to Access Dams Highway Traffic Volume (vehicles/hr) at Peak Travel Hours LOS 101 At Masten Ave Northbound: 7,100 Southbound: 8,700 E D At Cochrane Rd Northbound: 9,500 Southbound: 9,500 E D At Bailey Ave Northbound: 9,500 1 E Southbound: 9,000 1 At Hwy 85 Northbound: 7,400 Southbound: 9,500 C E 17 At Bear Creek Rd Northbound: 5,600 E - F Southbound: 5,300 At Lark Rd/SR 85 Northbound: 7,800 Southbound: 7,300 D 85 At Winchester Blvd Northbound: 9,000 Southbound: 8,600 1 Value is from 2006 data. SOURCE: Caltrans 2007 F E June 2011 Page 3-260

313 Section 3.10 Traffic and Transportation CHAPTER 3 ALTERNATIVE TRANSPORTATION AND TRAILS PUBLIC TRANSPORTATION Alternative transportation consists of on-street and off-street recreational trail systems, unpaved roads in rural areas, transit systems including the Santa Clara Valley Transportation Authority (VTA) bus and light rail systems, and Caltrain. Public transit connecting to the subject dams is limited, as most dams are located in rural areas (VTA 2009). TRAILS Several agencies construct and maintain a wide array of recreational trail systems at many of the dams and throughout the project area. The trails range from on-street bicycle lanes that share the road surface with motor vehicles to off-street and rural trails which provide separate paths for bicycles, equestrians, joggers, and hikers. Recreational trails are further described in Section 3.11 Recreation of this document REGULATORY SETTING Federal and State There are no federal or state regulations pertaining to traffic and transportation that are relevant to the DMP Local SANTA CLARA GENERAL PLAN The Santa Clara County General Plan (1994) includes a transportation chapter for both the rural unincorporated parts of the County and the urban parts of the County. Strategies for both the rural and urban areas of the County include: Develop land use patterns that support alternative transportation Manage system efficiency and congestion Anticipate and plan for future transportation demand Provide for non-motorized circulation in rural residential communities Preserve and enhance scenic qualities adjacent to scenic rural roads The Santa Clara County General Plan also has regulations regarding mining and mine access that is particularly relevant to work that may be performed at Lenihan Dam and Stevens Creek Dam due to its proximity to Lexington Quarry and Stevens Creek Quarry. The General Plan states: To ensure that mineral resource deposits remain available for future quarrying and transport, land use policy must prevent development that is incompatible with those operations from encroaching upon the site and along major hauling routes and precluding the use of those deposits. June 2011 Page 3-261

314 Section 3.10 Traffic and Transportation CHAPTER SIGNIFICANCE CRITERIA The project would have significant effects on or from traffic and transportation if it would: Exceed, either individually or cumulatively, level of service standards established by local or regional agencies for designated roads or highways; or otherwise cause a substantial increase in traffic in relation to the planned or designated traffic load and capacity of the circulation system Substantially increase hazards or result in substantial safety risks due to a design feature (e.g., sharp curves, or dangerous intersections) or incompatible uses (e.g., haul routes through residential neighborhoods or by schools) Result in inadequate emergency access or interfere with an adopted emergency evacuation plan Result in incompatible land uses through inadequate parking capacity or parking/staging on residential streets Conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities IMPACTS AND MITIGATION Impact: Exceed, Either Individually or Cumulatively, Level of Service Standards Established by Local or Regional Agencies for Designated Roads or Highways; or Otherwise Cause a Substantial Increase in Traffic in Relation to the Planned or Designated Traffic Load and Capacity of the Circulation System OVERVIEW Maintenance activities would require a limited number of vehicles (generally no more than 15 at a time) in order to perform work on the dam sites. Only one maintenance activitiy is usually conducted at any site at a time. None of the maintenance areas are within a highway corridor, but some project areas would be on or adjacent to County roads. Traffic generation from DMP activities would be consistent with existing levels of District dam maintenance traffic, would continue to be limited to generally no more than 15 vehicles at a time and would not significantly contribute to roadway congestion from equipment and worker transport to the sites. SURFACES AND/OR EARTHWORK Surfaces work includes vegetation management, burrowing rodent control, erosion repair and bank stabilization, road and boat ramp work, embankment repair and debris removal. Traffic generated from surfaces work would be limited to worker transport vehicles and potentially some trucks and heavy equipment transported to the site for activities requiring ground disturbance. Past maintenance activities have June 2011 Page 3-262

315 Section 3.10 Traffic and Transportation CHAPTER 3 shown that vegetation maintenance requires no more than five vehicles; rodent control seven vehicles; erosion control seven vehicles; embankment repair six vehicles; and trash removal six vehicles. Travel of any large vehicles transporting equipment to and from the site would be restricted to the start and end of project activities and would have a less than significant effect impact to traffic. Surfaces work, such as road repair and debris removal, may require additional trips with the transport of fill and/or the removal of debris. The average dump truck can haul approximately 40 cubic yards of material. Debris removal may require up to three trucks. Fill hauling could require as many as 9 or 10 trucks (for a road repair requiring 500 feet of gravel, 10 feet wide, by 2 feet deep). Up to 10 round trips generated by road repair activities, which is consistent with existing maintenance trips, and are not likely to significantly impact the highway system. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Traffic generated by maintenance of appurtenant structures would be limited to maintenance worker transport vehicles, some heavy equipment (concrete mixers), and trucks to transport materials (new valves or other equipment). Traffic generated for maintenance of appurtenant structures would be limited to less than 10 vehicles at a time for most projects and would be consistent with existing maintenance traffic levels. Equipment would be transported to the site and would be staged and remain at the dam for the duration of time that the equipment is needed. Traffic generation would be limited and would not cause or contribute to congestion on public roads. INSPECTIONS, MONITORING AND EXPLORATORY WORK Traffic generated for inspections and monitoring would be limited to one to five transport vehicles. Inspections occur monthly to annually, usually over a day to a week time period with one visit to each dam facility. Traffic generation from inspection and monitoring activities would not have an impact on congestion or traffic because of the limited number of vehicles required. Exploratory work could require heavy equipment and import/export of material, such as gravel, fill, drills, etc. Equipment would remain on site during activities and would only contribute to traffic loads at the beginning and end of a project. The exploratory work generally would not require more than a few trucks and the equipment would not generate or exacerbate traffic on public roads. RESERVOIR DEWATERING Vehicles and personnel may be necessary to monitor flow rates and downstream conditions. Individual dam specific dewatering plans would be developed for each reservoir (MM General-3). These plans would require the District to include details including vehicles and equipment necessary for lowering reservoir levels. Reservoir dewatering would most likely not require more than a few trucks. This volume of traffic would not be enough to exacerbate traffic conditions on roads. June 2011 Page 3-263

316 Section 3.10 Traffic and Transportation CHAPTER Impact: Substantially Increase Hazards or Result in Substantial Safety Risks Due to a Design Feature (e.g., Sharp Curves or Dangerous Intersections) or Incompatible Uses OVERVIEW The proposed project would not include any new public roads or design features that could increase traffic hazards. Activities may require temporarily closing sections of roadway, such as along Anderson Dam and Lenihan Dam (which have public access across their crests), to move equipment or to perform work on appurtenant structures. The only dams in the DMP in a residential area are at Rinconada Water Treatment Plant which regularly has truck deliveries to receive chemicals and remove sludge, and has a haul route already established to minimize impacts; and Vasona Reservoir which has partial access of University Avenue. The District implements BMP TR-1 on activities that may impact local roadways. BMP TR-1 includes public safety measures, such as use of construction signs, use of traffic control personnel, use of warning fencing, etc., and would be implemented in any area where heavy equipment or other maintenance work could affect traffic. Mitigation measures would be implemented where necessary to minimize hazards as discussed below. Impacts would be less than significant with mitigation. SURFACES AND/OR EARTHWORK Surfaces work (e.g., vegetation management, burrowing rodent control etc.) would take place on the dam face and surrounding areas and not on public roads. These activities would not generate many trips of heavy equipment or supplies and would not generate significant traffic hazards. Erosion control and bank hardening could occur at the toe of the dam and around other structures near slopes, which would not be near public roads. Erosion control could require the use of heavy equipment to transport in fill materials such as rock riprap, etc. Road repairs could require transport of gravel trucks, rollers, whackers, and other vehicles to the sites. Some surfaces work, such as major embankment repairs or instrumentation maintenance, may require staging or temporary shutdown of a lane along the crest of Anderson Dam or Lenihan Dam. These are the only two reservoirs with public access across the crest of the dam. 26 The District would obtain encroachment permits for any work along Alma Bridge Road. The encroachment permit would include the necessary traffic safety measures that the District would implement. The County requires traffic control plans for projects that are located within County expressway systems or principal arterial roadways. The District would contact the Santa Clara County Roads and Airports Department for information regarding the permit process prior to application and to inquire about the status of their permit. The potential impact from surface and earthwork is less than significant. 26 Alma Bridge Road across Lenihan Dam is a County road. Anderson Dam has a road across the crest of the dam which is open the public as part of recreationally access to Anderson Reservoir, but owned by the District. June 2011 Page 3-264

317 Section 3.10 Traffic and Transportation CHAPTER 3 Lexington Quarry is located to the east of Lenihan Dam on Limekiln Canyon Road and Alma Bridge Road is used for access to Highway 17. Under current operating limitations, Lexington Quarry is authorized to handle a maximum of 151 trucks per day, and can generate up to 302 daily truck trips. Access to the quarry from Highway 17 is via Alma Bridge Road and Lime Kiln Canyon Road. Truck loading operations are between 6:30 a.m. and 5:00 p.m., Monday through Friday, with no trucks loaded at the quarry on weekends or holidays (SCVWD 2005a). Blocking Alma Bridge Road could affect truck trips associated with mine operations, which is a potentially significant impact. MM Traffic-1 is designed to address the Santa Clara Valley General Plan Policy protecting access to mineral resources (quarries), such as the Lexington Quarry east of Lenihan Dam. MM Traffic-1 requires the District to coordinate with the quarry operations manager to ensure access and to provide a staging and access plan to the County (if Alma Bridge Road must be blocked). This measure would be implemented to minimize impacts to less than significant levels. Stevens Creek Dam has adequate space to provide staging and parking off the public road, and access to Stevens Creek Quarry would not be impacted by maintenance activities. MITIGATION MEASURE MM Traffic-1: Prior to staging and access of equipment at Lenihan Dam that could impede trucks from accessing Lexington Quarry via Alma Bridge Road, the District would consult with the quarry s operations manager or equivalent personnel to establish specific measures to ensure vehicular access for quarry vehicles. The District would provide a Staging and Access Plan to Santa Clara County that will specifically address the issues of quarry access (based on the consultation) to ensure adequate access to the quarry. MAINTENANCE OF DAM APPURTENANCES AND EQUIPMENT Traffic impacts from maintenance of appurtenant structures and equipment would be similar to effects from surfaces work. Potential effects would be limited to hazards arising from transport and parking of vehicles and equipment to the dam sites. MM Traffic-1 would be implemented to minimize potential effects from trucks, safety hazards, and access issues to Lexington Quarry to less than significant levels. Most maintenance of appurtenant structures and equipment would occur on the dam face or surrounding areas, away from public roads and would therefore not cause traffic hazards. INSPECTIONS, MONITORING, AND EXPLORATORY WORK There would be no traffic hazards caused by inspections and monitoring. Inspections and monitoring would be performed at each site and do not require heavy equipment or the transport of materials. Exploratory work can include ground disturbance, boring, drilling, construction of temporary access roads, and excavation, backfilling and compaction. Geotechnical explorations are included in exploratory work. Exploratory work could require heavy equipment, much like certain surfaces work (road repair, erosion and bank June 2011 Page 3-265

318 Section 3.10 Traffic and Transportation CHAPTER 3 stabilization, and debris removal) and some appurtenant structure maintenance. The District implements BMP TR-1 for all activities where staging or work activities could interfere with traffic. MM Traffic-1 would be implemented for any work that may limit access to Lexington Quarry. With implementation of these measures, the potential impact is less than significant. RESERVOIR DEWATERING Additional vehicles and personnel may be necessary for monitoring flow rates and downstream conditions. MM General-3 would require the development of a dewatering plan for each dam. This plan would require the District to include details including equipment necessary, including worker vehicles, for lowering reservoir levels. Reservoir dewatering is unlikely to require more than a few trucks. The overall impact would be less than significant Impact: Result in Inadequate Emergency Access or Interfere With an Adopted Emergency Evaluation Plan The DMP activities along roadways and some recreational trails could block or slow emergency access. Table lists the dams and the potential for emergency access hazards resulting from dam maintenance. The proposed project has the potential to cause significant impacts by impeding emergency access vehicles. Vehicles and materials that impede emergency access could have a potentially significant effect in the event of an emergency. MM Traffic-2 requires that all maintenance activities, including staging of equipment and materials, be conducted in a manner that maintains unimpeded emergency access. With the application of MM Traffic-2, effects on emergency access would be less than significant. Table : Potential for Emergency Access Hazards by Dam Potential Dam to Inhibit Emergency Location Access Almaden Dam Yes Almaden Dam is accessible by Alamitos Road, which is two-lane road with limited shoulders. Staging and access for maintenance work would occur off of Alamitos Road. Maintenance activities could create a hazard for emergency vehicles using the roadway. Anderson Dam Yes Anderson Dam has a road that crosses the dam providing access to the northern side of the dam and spillway. Any work that uses the road for staging or is conducted on the roadway would hinder access. Anderson Dam also has a boat ramp on the southern side that provides boat loading and surface access to the reservoir. This boat ramp should be kept clear to provide emergency access to the reservoir. Calero Main Dam No Calero dam has adequate parking and a well developed access road at the dam entrance off of McKean Road. Calero Auxiliary Dam Yes Calero Auxiliary Dam has limited space for maintenance vehicles. Staging and access for maintenance work would occur off of McKean Road, which is a narrow two-lane roadway. Maintenance activities could create a hazard for emergency vehicles. Chesbro Dam Yes Access to Chesbro Dam is provided by Oak Glen Avenue, which is June 2011 Page 3-266

319 Section 3.10 Traffic and Transportation CHAPTER 3 Table : Potential for Emergency Access Hazards by Dam Potential Dam to Inhibit Emergency Access Location a two-lane road with a limited shoulder. Staging at the access point could create a hazard for emergency vehicles using the roadway. Coyote Dam No Coyote Dam is located at the end of Coyote Reservoir Road. The roadway is used exclusively for dam access. The access to the dam is located at the end of a dead end cul-de-sac and would not create an emergency access hazard. Coyote Percolation No Ponds Dam Fellows Dike No Fellows Dike is not near an emergency access route. A dirt roadway from McKean Road accesses the dike and it is located approximately 0.5 mile from the access point. Vehicles would not be staged, used, or stored on or near an emergency access route. Guadalupe Dam Yes Guadalupe Dam is accessible by Hicks Road, which is a two-lane road with a limited shoulder. Staging and access for maintenance work would occur off of Hicks Road. Maintenance activities could create a hazard for emergency vehicles using the roadway. Lenihan Dam Yes Alma Bridge Road provides access to the Dam and is also an emergency access route to areas east of the dam. There are several parking areas at the dam for staging and access, but work may involve encroachment into the roadway and could create an emergency access hazard. Rinconada Treated Water Reservoir Dam Stevens Creek Dam No No Parking, staging, and access at the dam are available at the Rinconada Water Treatment Plant. Stevens Canyon Road passes Stevens Creek Dam. It has a broad shoulder. Stevens Creek Dam has sufficient on-site parking for maintenance vehicle staging and access. Uvas Dam Yes If vehicles are staged on Uvas Road at the point of access to the dam, the vehicles could create an emergency access hazard. Uvas Road is two lanes with no shoulder and large vehicles could create a difficult passage for emergency vehicles traveling on Uvas Road. Vasona Dam Yes Vasona Dam is located in a residential neighborhood and all roads accessing the Dam are narrow residential roadways. Any staging or storage occurring on or along these roadways could create an emergency access hazard. MITIGATION MEASURE MM Traffic-2: Prior to commencing any activities that could block a roadway, the District will ensure that emergency access is accommodated through all phases of the activity. The District shall notify the area s emergency service provider(s) to advise of the activity prior to starting. June 2011 Page 3-267

320 Section 3.10 Traffic and Transportation CHAPTER Impact: Result in Incompatible Land Uses Through Inadequate Parking Capacity or Parking/Staging Activities on Residential Streets Staging and access within suburban areas near Vasona Dam and Rinconada Treated Water Reservoir Dam may require parking vehicles along the outside lane of the roadways, in existing public and private parking lots, or in street parking spaces. The District would implement BMP TR-1 whenever a public road would be impacted. Staging and parking at Anderson dam could temporarily remove a few (usually less than 10) spaces of on-street or off-street parking from the available supply of well over 100 spaces. Work on the control building and inlet structure at Lenihan could require temporarily closing the entire east side parking lot for staging (the Lexington Reservoir County Parking Lot). The District would inform the Santa Clara County Parks and Recreation Department prior to work in the area that would require full use of the parking lot. While use of the parking lot may impede recreational use, the effect is less than significant because it would be temporary in nature. No public parking is provided at Almaden and Guadalupe, but the District maintains areas for parking and staging that would not interfere with access on public roads. Other reservoirs have public parking that is separate from areas where dam maintenance would occur and the District would be able to park and stage without impacting public parking or adjacent streets. Any impacts from parking or staging would be temporary and less than significant because the loss would be only for a relatively short period of time. Work would most likely be performed during business hours when parking demand for recreational and residential use is less than on weekends and during evening hours Impact: Conflict With Adopted Polices, Plans, or Programs Supporting Alternative Transportation Many dam facilities include public use trails, which are generally used for recreational purposes subject to the terms of the Master Lease with County Parks and Recreation. However, a limited number of people may use these trails as alternative transportation. Maintenance activities may result in temporary trail closures to protect users from heavy equipment and the maintenance activities. Most maintenance work included in the DMP would last for no more than a matter of days, and these temporary impacts are considered less than significant. Also, where maintenance work would cause temporary disruption of a path or trail, the District would provide alternative access around the work activity area, if feasible. As such the potential impact to alternative transportation is less than significant MITIGATION MEASURES MM Traffic-1: Prior to staging and access of equipment at Lenihan Dam that could impede trucks from accessing Lexington Quarry via Alma Bridge Road, the District would consult with the quarry s operations manager or equivalent personnel to establish specific measures to ensure vehicular access for quarry vehicles. The District would provide a Staging and Access Plan to Santa Clara County that will specifically address the issues of quarry access (based on the consultation) to ensure adequate access to the quarry. June 2011 Page 3-268

321 Section 3.10 Traffic and Transportation CHAPTER 3 MM Traffic-2: Prior to commencing any activities that could block a roadway, the District will ensure that emergency access is accommodated through all phases of the activity. The District shall notify the area s emergency service provider(s) to advise of the activity prior to starting. Residual Impacts After Mitigation All impacts would be reduced to less than significant levels with implementation of the mitigation described here. Best Management Practices (See Mitigation Monitoring and Reporting Program (Appendix V) for complete text of BMPs) TR-1: Public Safety Measures June 2011 Page 3-269

322 Section 3.11 Recreation CHAPTER RECREATION ENVIRONMENTAL SETTING Santa Clara County acquired its first parkland in 1924, with the purchase of 400 acres near Cupertino, which became Stevens Creek County Park (Santa Clara County Parks Department 2006). The current regional park system for the County includes 27 parks and encompasses approximately 45,000 acres. Each of the dams and reservoirs (with the exception of Rinconada Treated Water Reservoir Dam) are located within Santa Clara County regional parks. The regional parks surrounding each dam and reservoir are generally larger in size (over 200 acres) than local or neighborhood parks. Many of the trails in the County parks have regional significance because they cross jurisdictional boundaries and provide links to other recreational facilities. These trails provide hiking, off-road cycling, and/or equestrian opportunities. Table lists the dams and reservoirs, the parks in which the dams and reservoirs are located, and the activities and uses offered at the parks. Table : Parks Surrounding District Reservoirs Reservoir Park Name Facilities/Uses Almaden and Almaden Quicksilver Hiking, equestrian, biking trails, picnic areas. Guadalupe County Park Anderson/Coyote Lake County Park Power and non-power boating, fishing, float tube fishing, jet skiing, picnic areas, hiking, biking, horse trails. Calero Calero County Park Power and non-power boating, sailing, fishing, water and jet skiing, picnic areas, hiking and equestrian trails. Chesbro Chesbro Reservoir Non-power boating, fishing, sailing, kayaking. County Park Coyote Coyote Lake-Harvey Bear Ranch County Park Power boating, jet skiing, waterskiing, sailing, canoeing/kayaking, and fishing. Boat launch ramp, two docks, 3-lane concrete ramp, fishing, picnic areas, hiking, biking, equestrian trails. Coyote Percolation Metcalf Park Fishing, picnic areas, basketball, volleyball, playground. Ponds Lexington (Lenihan Dam) Stevens Creek Lexington Reservoir County Park Stevens Creek and Upper Stevens Creek County Park Electric powered boating, sailing, row boating, boat launch, non-gas powered boating, picnic areas, and fishing. Fishing, non-power boating (kayaking), picnic area, hiking, biking equestrian trails, archery. Uvas Uvas Reservoir Non-gas powered boating, fishing, picnic areas, sailing, kayaking. Vasona Vasona and Los Gatos Creek County Parks Non-power boating, paddle and row boating, fishing, picnic areas REGULATORY SETTING Federal and State There are no federal regulations related to recreation that are applicable to the DMP. June 2011 Page 3-270

323 Section 3.11 Recreation CHAPTER Regional and Local SANTA CLARA COUNTY GENERAL PLAN Santa Clara County General Plan ( ) was adopted December 20, 1994 (Santa Clara County 1994). The County established a blueprint for the regional park system when the County first established its General Plan in the 1960s. The plan was to develop a series of major regional parks located in the foothills and mountains around the valley. These regional parks would make County land available for public recreation as examples of the County s finest natural resources. Recreational trails and scenic highways were proposed to link these regional parks with one another and provide access from the valley floor (Santa Clara County 1994). The General Plan chapter, Parks and Recreation: Rural Unincorporated Area Issues and Policies, contains the following policies related to regional parks: Policy R-PR 4: The public open space land system should provide for recreation activities compatible with the enjoyment and preservation of each adjacent and nearby regional park lands. Policy R-PR 5: Water resource facilities, utility corridors, abandoned railroad tracks, and reclaimed solid waste disposal sites should be used for compatible recreational uses, where feasible. Policy R-PR 31: Public improvement projects, such as road widening, bridge construction, and flood control projects, that may impact existing or proposed trails, should be designed to facilitate provision of hiking, bicycling, and equestrian paths. June 2011 Page 3-271

324 Figure : Dam Sites in Regional Parks June 2011 Page 3-272