Watershed Management and Urban Runoff Management Integration Report

Transcription

1 June 29, 2001 Santa Clara Valley Urban Runoff Pollution Prevention Program Watershed Management and Urban Runoff Management Integration Report Submitted in fulfillment of NPDES Permit Provision C.10 Milpitas Palo Alto Cupertino Los Altos San Jose Sunnyvale Santa Clara Los Altos Hills Mountain View Santa Clara County Santa Clara Valley Water District West Valley Communities Campbell, Los Gatos, Monte Sereno, Saratoga

2 WATERSHED MANAGEMENT AND URBAN RUNOFF MANAGEMENT INTEGRATION REPORT Submitted in fulfillment of NPDES Permit Provision C.10 June 29, 2001

3 TABLE OF CONTENTS INTRODUCTION... 1 Background SCVURPPP Watershed Vision... 1 WATERSHEDS RELEVANT TO DISCHARGERS... 2 WATERSHED CHARACTERISTICS... 6 Land Use... 6 Imperviousness... 6 Land Development... 7 Development in Riparian Corridor... 7 Channel Modifications... 7 PROGRAM ELEMENTS RELATED TO WATERSHED CHARACTERISTICS...13 WATERSHED PRIORITIZATION...18 Watershed Assessments...18 Prioritization Criteria...20 RECOMMENDATIONS AND CONCLUSIONS...24

4 June 29, 2001 WATERSHED MANAGEMENT AND URBAN RUNOFF MANAGEMENT INTEGRATION REPORT NPDES Permit Provision C.10 INTRODUCTION This report is submitted in fulfillment of the Santa Clara Valley Urban Runoff Pollution Prevention Program (Program) NPDES permit Provision C.10.a. This permit provision requires the Program to submit a report to the Regional Board concerning the integration of watershed management activities into the Urban Runoff Management Plan (URMP). Watershed management measures are control measures and other actions in the URMP that are appropriately implemented on a watershed basis. The permit provision recognizes that watershed management measures seek to develop and implement the most cost effective approaches to solving identified problems and to coordinate these activities with other related programs. This technical report responds to the following required permit provision items (C.10.a.i., ii., and iii): i. Identify the watersheds that are relevant to each Discharger; ii. Identify key characteristics related to urban runoff in each watershed and program elements related to such characteristics; iii. Provide a priority listing of watersheds to be assessed and a schedule for conducting such assessments in conjunction with the SCBWMI. In this report, the key watershed characteristics and program elements are identified on a planning level as they relate to urban runoff and watershed management measures. More detail on watershed characteristics can be found in the Watershed Management Report Volume 1: Watershed Characteristics Report (SCBWMI February 2001) and further detail on program elements can be found in the Program and Co-permittee Urban Runoff Management Plans (1997, updated 2000). This vision outlines the principles and approaches that the Program and its co-permittees will use during the term of the next permit to support better management of the Santa Clara Basin watershed through the implementation of the most practicable urban runoff and stormwater control measures. Background SCVURPPP Watershed Vision The SCVURPPP s permit application and recent NPDES permit issue contain reference to the Program s vision 1 as it relates to the integration of the urban runoff program and watershed management goals and approach. This vision outlines the principles and approaches that the Program and its co-permittees will use during the term of the next permit to support better management of the Santa Clara Basin watershed through the implementation of the most practicable urban runoff and stormwater control measures. 1 SCVURPPP vision position entitled Watershed 2000 A Vision of the Santa Clara Valley Urban Runoff Program s Role in Watershed Management and the Santa Clara Basin Watershed Management Initiative December 9, F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 1

5 June 29, 2001 The Program s approach for supporting watershed management and the Watershed Management Initiative can be articulated through the following principles: The goal of the Program and its Co-permittees is to maintain water quality and protect the beneficial uses of the water bodies in the Santa Clara Basin through the implementation of control measures to the maximum extent practicable. Successful watershed management must be a community-wide, stakeholder-driven effort. Regulatory agencies, the business community, environmental advocates, and local government must not only agree on what needs to be done each stakeholder must share the burden of implementing watershed management plan recommendations. The Co-permittees recognize it can be difficult to separate many urban runoff issues from the general impacts of urbanization resulting from the cumulative effects of land uses. The Co-permittees understand that their activities have the potential to impact water quality and beneficial uses; conversely such activities can create opportunities to improve water quality and enhance aquatic resources. Given those principles, the Co-permittees envision the roles of the Program and that of the WMI as follows: The Program s activities pursuant to the NPDES permit provide key methods to assist co-permittees and other local agencies to incorporate appropriate watershed management recommendations into their decision-making and specific watershed protection approaches into their day-to-day operations. The SCBWMI, as a stakeholder process, provides the tools to identify community goals and issues, and facilitates the development of common ground between stakeholders to recommend to policy-makers the actions needed to better manage watershed resources. The following integration report is based on the principles and roles identified in the Program s Vision document. WATERSHEDS RELEVANT TO DISCHARGERS The Program is an association of 13 cities and towns in Santa Clara Valley, the County of Santa Clara, and the Santa Clara Valley Water District that share a common permit to discharge storm water to South San Francisco Bay. These 15 dischargers are referred to as co-permittees in the Program. Permit Provision C.10.a.i. requires this report to identify the watersheds relevant to each discharger. Table 1 lists each co-permittee and the corresponding Santa Clara Basin watersheds that are within their municipal boundaries. Each co-permittee occupies multiple watersheds. Therefore, the remaining sections of the report will discuss watershed management actions, characteristics, and program elements on a watershed basis rather than by co-permittee. Figure 1 shows the Santa Clara Basin with both watershed and co-permittee city boundaries overlaid. F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 2

6 June 29, 2001 Table 1. Watersheds Relevant to Co-permittees Co-permittee Name Watershed Population (Jan. 2000) Campbell Cupertino Los Altos Los Altos Hills Los Gatos Milpitas Monte Sereno Mountain View Palo Alto San Jose Santa Clara San Tomas Guadalupe Stevens Calabazas Sunnyvale East Adobe Permanente Stevens Adobe Matadero/Barron Permanente San Tomas Guadalupe Coyote Lower Penitencia San Tomas Guadalupe Adobe Permanente Stevens Sunnyvale West San Francisquito Matadero/Barron Adobe Stevens Permanente San Tomas Guadalupe Coyote Lower Penitencia Calabazas Calabazas San Tomas Guadalupe Community Characteristics 40,850 Mixed residential, commercial, and light industrial land use; no water utility 52,900 Mixed residential, commercial, and light industrial land use 28,600 Mixed residential, commercial, and light industrial land use 8,300 Entirely low-density residential land use; no industry; no water utility 30,450 Mixed residential and commercial land use; no water utility 65,300 Mixed residential, commercial, and light industrial land use 3,470 Entirely residential land use; no industry; no water utility or corporation yard 76,000 Mixed residential, commercial, and light industrial land use 61,500 Mixed residential, commercial, and light industrial land use 923,600 Large urban area with mix of high/medium/low density residential, commercial, and light and heavy industrial land use 102,900 Mixed high/medium density residential, commercial, and light and heavy industrial land use F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 3

7 June 29, 2001 Co-permittee Name Watershed Population (Jan. 2000) Santa Clara County (unincorporated) SCVWD Saratoga Sunnyvale unincorporated land Calabazas San Tomas Sunnyvale East Sunnyvale West Stevens Calabazas 105,200 Not applicable Community Characteristics Mixed residential, commercial, and light industrial land use; no water utility Public agency responsible for water resource management (water supply and flood control) 31,300 Mixed residential and commercial land use; no water utility 133,200 Mixed high/medium density residential, commercial, and light and heavy industrial land use F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 4

8 San Francisco South Bay Arroyo la Laguna Alam eda C ounty Santa C lara County N PA LO A LTO Baylands MILP IT AS San Francisquito Matadero/Barron Adobe MOUNTAI N V IE W Stevens Sunnyvale West Sunnyvale East Low er Penitencia Miles LO S ALTOS HI LLS LO S ALTOS SUNNYV ALE Calabazas SANT A CLARA Coyote Perm anente CUP ERTI NO San Tomas Guadalupe SA N JOSE San Mateo County SA RA TOGA CA MP BE LL MONTE SERENO LO S GAT OS Legend Landuse Residential Industrial/C ommercial MORGA N HILL Open Area City Boundary W MI W atershed Boundary Figure 1. W atershed, Land Use, and Jurisdictional Boundaries in the Santa Clara Basin.

9 June 29, 2001 WATERSHED CHARACTERISTICS Key watershed characteristics that are relevant to urban runoff are identified below and summarized in Table 2. General, planning level quantifications of the watershed characteristics were developed from data presented in the Watershed Management Report Volume 1: Watershed Characteristics Report (SCBWMI February 2001). These watershed characteristics will be discussed further as they relate to Program elements and prioritization of watershed assessments. The watershed characteristics that have been identified as relevant to urban runoff are: Land Use Land Use Imperviousness Land Development (existing and projected) Development in Riparian Corridor Channel Modifications Land use is important both to characterize a watershed and to help target urban runoff pollution prevention programs appropriately. For the purposes of this report, land use was divided into three categories: residential, industrial/commercial and open areas. Note that categories for residential and industrial/commercial areas are not meant to imply a difference in pollutant concentrations from these sources. Rather, land uses are noted because different types of development can change a watershed by altering its structure and ecological functions, and creating impervious surface. Thus, the key factor for this report is the difference between developed and non-developed land. Land uses in each watershed are reported in Table 2 as total acreage of developed land and as the percentage of the watershed that is developed. Developed land includes residential, commercial and industrial land uses. Figures 2 through 5 show land uses for watersheds within the Basin. Co-permittee city boundaries are also included on the figures. Figure 2 shows Guadalupe and San Tomas watersheds. Figure 3 shows the Coyote and Lower Penitencia watersheds. Figure 4 shows San Francisquito, Matadero/Barron, Adobe, Permanente, Stevens, Sunnyvale East, Sunnyvale West, and Calabazas watersheds. Figure 5 shows Arroyo la Laguna watershed. Imperviousness The term imperviousness refers to the surface area (roads, sidewalks, rooftops, parking lots, etc.) within a watershed that prevent or prohibit rainfall from infiltrating into the soil and potentially transported to groundwater. Increased imperviousness can produce larger, more frequent floods due to a decrease in transport time for large fluxes of runoff. (WMI February 2001). Thus, watershed imperviousness is directly related to urban runoff flow. The amount of impervious land within each watershed is presented in Table 2 as total acreage and percentage of the watershed area. The watershed imperviousness values incorporated in this report were taken from estimates included in the SCBWMI s Watershed Characteristics Report. The WCR explains that imperviousness was estimated using ABAG 1995 land use data. Multiplying land use acreages by coefficients that related specific land uses to imperviousness produced estimates of total F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 6

10 June 29, 2001 imperviousness for each watershed. Some imperviousness coefficients were drawn from values in the literature. The remaining coefficients were developed by Eisenberg, Olivieri, and Associates (EOA 1999). Land Development Land development is another important watershed characteristic related to urban runoff. Important urban runoff considerations include not only existing land development, but also projected future land development in each watershed. Table 2 presents data on existing development (acreage and percentage of watershed), projected development, and the area of land that is protected from development in each watershed. Development in Riparian Corridor The riparian corridor refers to the area along side of a stream or channel. Riparian vegetation is important because it provides erosion control, habitats for biota/wildlife, and food. Riparian corridors also help control flood velocities and sediment input, moderate water temperature, and maintain base flow in the dry season. Due to the riparian corridor s critical role in a stream s condition, the amount of development within the riparian corridor is presented as a separate watershed characteristic in Table 2. Channel Modifications As part of their flood protection and water supply programs, the SCVWD has modified the channel structure of many streams within the Santa Clara Basin. Stream channel modifications include creek bank and bottom stabilization, and construction of bypass channels, levees, floodwalls, and culverts. Modifications made to the channel structure of Basin streams can effect urban runoff by increasing the flow rate of discharge and affecting riparian vegetation, channel volume capacity, and bank erosion control. The SCBWMI WCR summarizes the number of linear feet of modified stream channel using several general channel types including natural unmodified, concrete channel, earth levee, excavated earth, slope concrete, slope rock and slope gabion. For the purposes of this report, channel modifications to specific Basin streams are not examined in detail. However, in future assessments of each individual watershed, it would be useful to identify the modifications made to particular sections of each stream and what portions of the streams are still in a relatively natural condition. F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 7

11 June 29, 2001 Table 2: Santa Clara Basin Watershed Characteristics Related to Urban Runoff Area (acres) 1 Developed Land Uses 2 Developed Land Within Riparian Corridor 3 Impervious Land Within Watershed 4 Protected Area5 % of Watershed Acres % of Riparian Corridor Acres % of Watershed Acres % of Watershed Acres Projected Development 6 % Developed Land (2020) Adobe 7, , , , ,300 Arroyo la Laguna 47, , , , , ,133 Baylands 20, , , , , ,159 Calabazas 13, , , ,420 Coyote 205, , , , , ,037 Guadalupe 108, , , , , ,609 Matadero/Barron 10, , , ,841 Lower Penitencia 18, , , , ,042 Permanente 11, , , , ,645 San Francisquito 27, , , , ,271 San Tomas 28, , , , , ,193 Stevens 18, , , , ,353 Sunnyvale East 4, , , ,490 Sunnyvale West 4, , , ,327 Notes 1 Watershed area data is from the Watershed Characteristics Report (February 2001), Table 4-4, p Developed Land Use data is the calculated sum of residential, commercial and industrial values from each of Tables 4-2 (p. 4-28) and Table 4-3 (p. 4-29) of the Watershed Characteristics Report (February 2001) 3 Developed Land Within the Riparian Corridor data is from the Watershed Characteristics Report (February 2001), Table 4-13, p. 4-94; Impervious Land Within Watershed data is from the Watershed Characteristics Report (February 2001), Table 4-10, p Protected Area data fis from the Watershed Characteristics Report (February 2001), Table 4-4, p Projected Development data is the calculated sum of residential, commercial and industrial values for the year 2020 and are taken from the Watershed Characteristics Report (February 2001), Table 4-7, p Acres F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 8

12 Baylands Land U se Legend Residential Industrial/Com m ercial Open Area City Boundary W M I W atershed Boundary SANT A CLARA San Tomas SA N JOSE CA MP BE LL Guadalupe SA RA TOGA MONTE SERENO LO S GAT OS N Kilo meters Figure 2. Land Use and Jurisdictional Boundaries in Guadalupe and San Tomas W atersheds.

13 Baylands MILPITAS Lower Penitencia Legend Land U se Residential Industrial/Com m ercial Open Area City Boundary W M I W atershed Boundary SAN JOSE Coyote N Kilo m eter s Figure 3. Land Use and Jurisdictional Boundaries in Coyote and Lower Penitencia W atersheds.

14 Baylands PA LO A LTO San Francisquito UNI NCO RP ORAT ED Matadero/Barron Sunnyvale W est MOUNTAI N V IE W LO S ALTOS Stevens Sunnyvale East LO S ALTOS HI LLS Permanente SUNNYV ALE PA LO A LTO Calabazas SANT A CLARA Adobe UNI NCO RP ORAT ED CUP ERTI NO SA N JOSE Land U se Legend Residential Industrial/Com m ercial Open Area City Boundary W M I W atershed Boundary SA RA TOGA N Kilo meters Figure 4. Land Use and Jurisdictional Boundaries for W atersheds in W estern Santa Clara Basin.

15 Legend Land U se Residential Industrial/Com m ercial Open Area City Boundary W M I W atershed Boundary Newark Fremont Arroyo la Laguna Alam ed a C ou nty San ta Cla ra C oun ty Baylands N Miles Figure 5. Land Use and Jurisdictional Boundaries in Arroyo la Laguna W atershed.

16 June 29, 2001 PROGRAM ELEMENTS RELATED TO WATERSHED CHARACTERISTICS An integral part of their NPDES permit, the Program and Co-permittees Urban Runoff Management Plan (URMP) focuses on storm water pollution prevention efforts in urban areas. The URMP consists of an area-wide plan and individual co-permittee plans describing what the co-permittees will do, collectively and individually, to reduce urban runoff pollution. The URMP describes the goals and objectives of the Program and its various elements, including monitoring and watershed management measures. The URMP contains model performance standards that may be modified as appropriate to fit local conditions and are implemented by the Co-permittees. These include: Illicit Connection and Illegal Dumping Elimination Activities Industrial/Commercial Discharger Control Program Public Streets, Roads, and Highways Operation and Maintenance Storm Drain System Operation and Maintenance Water Utility Operation and Maintenance Planning Procedures Construction Inspection In addition, the URMP presents a framework for the relationship between Program area-wide and Co-permittee specific Public Information/Participation (PI/P) activities, that the Program and Co-permittees use to develop and conduct PI/P tasks. Table 3 presents the existing program elements, future program elements and pollutant-specific elements, indicating which are appropriate for a watershed approach, i.e., an opportunity to coordinate urban runoff management measures within a particular watershed to achieve water quality benefits to the maximum extent practicable (MEP). Technically, all of the performance standards were developed using a watershed approach, as they were developed specifically for the municipalities in the Santa Clara Basin, with consideration of their community characteristics. However, the purpose of this analysis is to examine how the performance standards could be implemented in a way that recognizes the characteristics of individual watersheds ( sub-watersheds ) within the Basin (e.g., San Francisquito Creek, Guadalupe Creek, etc). Identification of elements as appropriate for a watershed approach indicates that some aspects of the performance standard could be implemented with consideration of a particular watershed s characteristics. For example, in a watershed with a relatively low percentage of impervious area and a large projected increase in developed area, land use planning decisions and development plan reviews would be more critical to the protection of water quality benefits than in a watershed that was nearly built-out. Program elements that were identified as not appropriate for a watershed approach, i.e., elements best implemented at a municipality level, are those for which significant municipal programs and procedures (such as inspection and maintenance programs) have been established to conduct these activities within each agency s jurisdiction. For these elements, there appears to be little environmental benefit to restructuring established programs to better coordinate activities on a watershed basis, assuming each agency is meeting the current performance standard. F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 13

17 June 29, 2001 Table 3 identifies Illicit Connection and Illegal Dumping Elimination Activities (ICID), New Development Planning Procedures, Construction Site Inspection, and Public Information/Participation (PI/P) as program elements that could be implemented with consideration of watershed characteristics and coordinated within a watershed. For each of these elements, Table 3 describes the watershed management issues related to implementation and potential action items in the identified watersheds. Mercury, PCBs, dioxin, and sediment were identified as pollutant-specific elements that could be addressed by a watershed approach. The key watershed characteristics related to urban runoff described in the previous section include: Land use Imperviousness Land development (existing and projected) Development in riparian corridors Channel modifications The program elements most directly related to all of these characteristics are the New Development Planning Procedures and Construction Inspection elements. In addition, there are pollutant-specific issues associated with each watershed. The ICID and PI/P elements are the best program areas in which to address these issues, if a known source of the pollutant is illegal dumping or improper public use or disposal and if the pollutant can be controlled by educating the public in that watershed about proper behavior. The PI/P element is also appropriate for increasing public awareness about local watershed issues and the need for public involvement in creek protection (in any watershed). F:\SC26-41 INTEGRATION REPORT\.INTEGRATIONV4.DOC 14

18 Program Element Table 3. Santa Clara Valley Urban Runoff Program Elements And Their Relationship to Watershed Management Issues Appropriate for Watershed Approach? 2 Existing Program Element with Performance Standard (PS) Illicit Connection and Illegal Dumping Elimination Activities (ICID) Yes Best Implemented at Municipality Level? 3 Is currently; could add creek focus Watershed Management Issues Related to Element Implementation Illegal dumping into creeks or storm drains with creek outfalls. Potential Action Items in Identified Watersheds 4 Reporting the location of ICID incidents by watershed to identify/address particular pollution issues Industrial/Commercial Discharger Control Public Streets, Roads and Highways Operation and Maintenance Storm Drain System Operation and Maintenance Water Utility Operation and Maintenance No Yes None No Yes None Yes Yes Trash management Coordination between SCVWD and adjacent Co-permittees regarding clean-up response, signage, and public education. No Yes None 2 Technically, all of the performance standards were developed using a watershed approach, as they were developed specifically for the municipalities in the Santa Clara Basin, with consideration of their community characteristics. A Yes in this column indicates that some aspects of the performance standard could be implemented with consideration of an individual-watershed s characteristics (e.g., Coyote Creek or San Francisquito Creek watershed). 3 A Yes in this column indicates that significant municipal programs and procedures (such as inspection and maintenance programs) have been established to conduct these activities within each agency s jurisdiction, and that there is little environmental benefit to restructuring these programs to better coordinate activities on a watershed basis, assuming each agency is meeting the current performance standard. 4 Pending results of current and/or future watershed assessment efforts. F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 15

19 Program Element New Development Planning Procedures Yes Table 3. Santa Clara Valley Urban Runoff Program Elements And Their Relationship to Watershed Management Issues Appropriate for Watershed Approach? 2 Best Implemented at Municipality Level? 3 Is currently; application of various Copermittee ordinances could be coordinated by watershed Construction Site Inspection No/Yes Is currently; application of Copermittee policy and ordinances could be coordinated by watershed Pest Management No Yes (and countywide level) Public Information/Participation 5 Yes Currently implemented at county-wide and local levels; could add watershed focus Future Program Element with Performance Standard Rural Public Works Maintenance and No Yes (primarily Support 6 County) Watershed Management Issues Related to Element Implementation Impacts of increases in amount of impervious surface in watershed on water quality and habitat Impacts of increases in peak runoff flows on habitat and channel stability Sediment discharges to 303(d) listed creeks (e.g. San Francisquito Creek) Local watershed awareness Need for public involvement in creek protection Potential Action Items in Identified Watersheds 4 Coordination of municipal land use planning and zoning efforts in less developed watersheds to minimize future impacts. Development of Hydromodification Management Plan (peak flow limitations) by watershed, per permit provision C.3.f. Additional erosion and sediment controls for construction sites in impacted watersheds Increased frequency of inspection at construction sites in impacted watersheds Watershed-specific education through Watershed Education & Outreach Campaign Creek-centered community projects (e.g. creek clean-up events, Adopt-a-Creek, etc.) 5 The PI/P Element does not have a formal performance standard; however the level of implementation expected of Co-permittees is defined in the reissued NPDES Permit Provision C.4. (Order , February 21, 2001). 6 As required in the reissued NPDES Permit Provision C.5. Performance standard to be completed by June 30, F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 16

20 Program Element Table 3. Santa Clara Valley Urban Runoff Program Elements And Their Relationship to Watershed Management Issues Appropriate for Watershed Approach? 2 Best Implemented at Municipality Level? 3 Watershed Management Issues Related to Element Implementation Pollutant-Specific Element Copper No Yes None specific to watershed pollutant is ubiquitous Nickel No Yes None specific to watershed pollutant is ubiquitous Mercury Yes Some pollution prevention actions Mercury hot spots associated with particular watersheds (i.e., Guadalupe) Pesticides No Yes None specific to watershed pollutant is ubiquitous PCBs and Dioxins Yes No Monitoring approach focused on identification of hot spots in particular watersheds Sediment Yes Some actions Sediment discharges to 303(d) listed creeks (e.g., San Francisquito Creek) Potential Action Items in Identified Watersheds 4 Copper Action Plan implementation (Provision C.9.a.) Nickel Action Plan implementation (Provision C.9.b.) Current mercury sediment monitoring program Additional participation in TMDL Pesticide Plan implementation (Provision C.9.d.) To be determined Additional erosion and sediment control requirements in impacted watersheds F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 17

21 WATERSHED PRIORITIZATION Permit Provision C.10.a.iii requires a priority list and schedule for watersheds to be assessed. Described below are the criteria used for prioritization. Criteria were developed based on watershed characteristics relevant to urban runoff. The three watershed characteristics criteria identified are: Projected increase in development Development within the riparian corridor Imperviousness These characteristics were quantified and ranked. Projected increase in development was quantified in terms of acreage and percentage of watershed. Watersheds were ranked according to greatest projected increase in development by acreage. Imperviousness was quantified based on acreage and percentage of watershed. Watersheds were ranked according to lowest percentage of imperviousness. Development within the riparian corridor was quantified in terms of acreage and percentage of watershed. Watersheds were ranked according to lowest percentage of development within riparian corridor. Equal weights were assigned to each of the three watershed criteria. Individual ranks were summed to develop an overall ranking. Using this watershed characteristics based prioritization as a starting point, a priority list was developed for the SCVURPPP assessments taking into consideration program elements, pollutant specific issues, and SCBWMI watershed prioritization work that has already been completed. Watershed Assessments The watershed assessment reports required by Permit Provision C.10.b must include the following: i. The Dischargers support for the SCBWMI by, among other things: (1) investigating beneficial uses and causes of impairment, (2) reviewing, compiling, and disseminating environmental data, (3) developing and implementing strategies for controlling adverse impacts of land use on beneficial uses, and (4) facilitating, implementing, and supporting relevant SCBWMI subgroups; ii. An assessment of each Discharger s implementation of watershed management activities; and, iii. A consideration of steps needed for continuous improvement in addressing priorities within each watershed. There are several assessments planned or ongoing in the Basin, including the WMI s assessment of the three pilot watersheds (San Francisquito, Upper Penitencia, and Guadalupe), the SCVURPPP s assessment of the Coyote watershed, and the Regional Board s planned assessment of Basin Watersheds as part of the State s Regional Monitoring and Assessment Strategy (RMAS). WMI Pilot Assessments: The WMI assessment is designed to use available data to determine whether beneficial uses/stakeholder interests are supported in various sub-watersheds and stream reaches in the Santa Clara basin. The results of the assessments are intended to be programmatic since they are based on available F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 18

22 data. The assessments may be refined as more data become available. The goal of the assessments is to begin to identify the factors that affect beneficial use support and achievement of stakeholder interests in Santa Clara Basin s streams as well as provide a scientific basis for selecting and evaluating alternative management strategies. The proposed procedure is founded on the concept that direct measures of the fitness of a waterbody to support a primary use/stakeholder interest are preferable to indirect measures. Indirect measures or indicators are proposed only where direct measures are impractical or limitations in the data prevent use of a direct measure. A principle aim of the assessment report is to organize, present, and convey the most relevant information regarding the condition of the water bodies as it relates to the primary uses, which include their suitability for supporting aquatic life and for swimming, providing safe drinking water, and how they function in response to high flows. Following the assessment of individual uses and interests by stream reach, the results of the assessment will be combined on a watershed basis and will integrate the results for the uses and interests. This integration will result in a matrix, which shows areas of support and non-support, and, where appropriate, potential limiting factors. The goal of this integration step is to address the overall health of the watershed and also is intended to address many stakeholder concerns regarding possible conflicts between protection from flooding and beneficial uses. Another goal is to identify data gaps and develop a monitoring plan. SCVURPPP Coyote Pilot Assessment: The goal of the Coyote Creek Watershed Pilot Assessment Project is to explore the relationships between selected local and regional approaches to watershed assessment. Specifically, the approach applied on Coyote Creek 7 will be refined along with how it may be used constructively with the SCBWMI s Framework for Conducting Watershed Assessments, and the RWQCB s Regional Monitoring and Assessment Strategy (RMAS) 8 and Stream Protection Policy (SPP). The specific objectives are to: Identify the major issues affecting watershed health in the Coyote watershed. Develop a list of appropriate management actions to preserve and enhance the Coyote watershed. Identify appropriate monitoring locations and provide baseline information for a long-term monitoring program for continued watershed assessment. Contribute to the SCBWMI s Watershed Assessment Report. Incorporate Coyote Creek into the RWQCB RMAS group of pilot watershed assessments. 7 Buchan, L.A.J., R.A. Leidy, and M. K. Hayden Aquatic resource characterization of western Mt. Hamilton stream fisheries. Prepared for The Nature Conservancy by Eisenberg, Olivieri and Associates Inc. in association with the United States Environmental Protection Agency. Sunnyvale, CA 74pp + app. 8 February 8, 2001 Memorandum from Steve Moore, RWQCB, to Interested Parties. F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 19

23 The initial phase will a) characterize factors affecting aquatic biological resources, b) evaluate the existing and potential condition of aquatic biological resources, and c) identify management actions to enhance aquatic biological health. The final product generated from this work will include discussion of the existing and near-term management activities/projects affecting the watershed, how these may influence stream function, current stream functional capacity and stream quality (present, future, and potential) given existing data, and recommendations for practical actions to improve and enhance the watershed in the short-term. The second phase will make recommendations for a long term monitoring strategy by identifying areas where consensus has not been reached on appropriate management actions due to lack of understanding of stream functions, and recommend additional research/monitoring to address these information gaps. The final project of this phase will be a memorandum identifying a set of specific studies, including monitoring locations and timeframe, which can be used to address specific questions and hypotheses within critical reaches. The third phase of this project will develop recommendations for how information and conclusions from Phases I and II can be used for the analysis of aquatic life Beneficial Use attainment. These recommendations will be described in a technical memorandum. RWQCB Regional Monitoring and Assessment Strategy: The RWQCB s most recent documentation of their Regional Monitoring and Assessment Strategy (RMAS) 9 describes an approach to selecting sites and parameters for watershed monitoring but does not describe how data collected as part of their monitoring program will be assessed. Instead, they intend to rely on statewide efforts once they become available (Moore 2001). Similar to the Coyote pilot assessment project, the monitoring approach they describe emphasizes characterizing watershed hydrogeomorphology and stream functions. Their approach differs in that they do not make such characterization a prerequisite to initiating water quality, biological and physical monitoring of streams. By conducting a functional assessment first, information or concerns regarding the impacts of a specific pollutant or stressor can be considered and further investigated within the context of ecosystem structure and function. Moreover, through several projects 10, the Coyote Creek watershed has been sampled for the past several years, providing a wealth of data for our assessment. Therefore, Coyote assessment approach compliments the RMAS and will provide a reasonable basis for linking evaluation of stream hydrogeomorphic functions to regulatory assessment of Beneficial Use attainment. Prioritization Criteria Watershed Characteristics Criteria were selected with the intent of targeting watersheds for earlier assessment where the most water quality benefits can be realized. The criteria are intended to focus attention on watersheds where the implementation of watershed-based urban runoff best management 9 February 8, 2001 Memorandum from Steve Moore, RWQCB, to Interested Parties. 10 The SCVURPPP s Storm Water Environmental Indicators Pilot Demonstration Project, the SCVWD s Fisheries and Aquatic Habitat Collaborative Effort, and the City of San Jose s Recycled Water Project. F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 20

24 practices (BMPs) will yield the results to the MEP. Watershed characteristics presented in Table 2 were reviewed to identify potential criteria for prioritization. Three watershed characteristicbased criteria were identified. Projected Increase in Development This criterion is quantified as the increase in development projected in the watershed between now and Figures for development increase were calculated by taking the difference between the percentage of the watershed projected to be developed in 2020 and the percentage currently developed. Table 4 presents the percentage increase and acreage increase in developed land for each watershed. Those watersheds with the greatest projected increases in development by acreage were assigned the highest priority for assessment. Imperviousness Table 5 shows the amount of imperviousness in each watershed. Watersheds were ranked according to the lowest percentage of imperviousness. The rationale for this approach is that watersheds with less imperviousness should be made a priority for assessment to help preserve their current state to the MEP. 1 2 Table 4. Projected Increases in Developed Land Watershed Increase in Development 1 % Increase Acreage Increase Rank 2 Adobe Arroyo la Laguna 9.5 3,713 1 Baylands Calabazas Coyote 2 3,667 2 Guadalupe 1.1 1,529 4 Matadero/Barron Lower Penitencia Permanente San Francisquito 6.3 1,701 3 San Tomas Stevens Sunnyvale East Sunnyvale West Data calculated from Table 4-7 in Volume One of the Watershed Characteristics Report (February 2001), p Rank is according to greatest increase in projected development F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 21

25 Table 5. Impervious Land Within Watershed 1 Impervious Land Within Watershed Watershed 1 Rank 2 % of Watershed Acres Adobe ,200 9 Arroyo la Laguna ,600 5 Baylands ,200 3 Calabazas , Coyote ,700 1 Guadalupe ,400 6 Matadero/Barron , Lower Penitencia ,800 7 Permanente ,900 8 San Francisquito ,700 2 San Tomas , Stevens ,300 4 Sunnyvale East , Sunnyvale West , Data taken from Table 4-10 in Volume One of the Watershed Characteristics Report (February 2001), p Rank is according to lowest percentage of impervious area Development within riparian corridor Riparian corridors are critical to the ecological and hydrologic functioning of watersheds. Table 6 shows the amount of development within the riparian corridor for each watershed. Watersheds were ranked according to the lowest percentage of development within the riparian corridor. The rationale for this approach is that the watersheds with less development within riparian corridors are probably the least impacted by development and it should be a priority to implement urban runoff BMPs to maintain their condition to the MEP. Pollutant Specific The previous section focused on watershed characteristics as criteria for prioritization. There are also pollutant-specific concerns within some watersheds that are potential considerations in prioritizing watersheds for assessment. Some pollutants of concern are ubiquitous in Basin watersheds while others are associated with specific watersheds. These include pollutants such as mercury, sediment, PCBs and dioxin that are of particular concern for some watersheds in the Basin. Therefore, another consideration for prioritization is whether a TMDL effort is underway or planned for a watershed. Mercury sources have been identified in the Guadalupe watershed and are being addressed in the development of a TMDL. Sediment is an identified problem in the San Francisquito watershed. Monitoring and investigation for hot spots is currently underway as part of the Joint Stormwater Agency project entitled Investigation of Urban Sources of Mercury, PCBs and Organochlorine Pesticides Year 2 (FY01-02), for which the SCVURPP is managing the overall project. Year 1 (FY00-01) results were published in a recent report entitled Joint Stormwater Agency Project to Study Urban Sources of Mercury and F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 22

26 PCBs, April 2001 (KLI). As part of year two, one of the SCVURPPP Co-permittees (the City of San Jose) will perform two case studies for selected drainages sampled during the initial survey (sampling sites SCV001 and SCV002). The intent of the case studies is to inform future monitoring and source identification efforts and to help devise strategies for controlling PCB discharges in urban runoff. As part of the case studies, concentrations of total PCBs and the distribution of homologs measured during the initial survey, the size of the drainage area, and land use composition would be used to site and prioritize further sampling efforts to identify sources or source areas. The case studies will include developing improved information on drainage areas and land use composition, both current and historical, for existing sampling locations. Table 6. Developed Land Within the Riparian Corridor Developed Land Within the Watershed Riparian Corridor 1 Rank 2 % of Riparian Corridor Acres Adobe Arroyo la Laguna ,237 2 Baylands ,770 6 Calabazas Coyote ,788 1 Guadalupe ,139 4 Matadero/Barron Lower Penitencia Permanente San Francisquito San Tomas , Stevens Sunnyvale East Sunnyvale West Data taken from Table 4-13 in Volume One of the Watershed Characteristics Report (February 2001), pp. 4-94; Rankings are according to lowest percentage of developed land within the riparian corridor SCBWMI Prioritization The Santa Clara Basin Watershed Management Initiative has invested significant time and effort in developing a prioritization of Basin Watersheds for the purposes of planning assessments. SCBWMI Work Group D submitted the Combined Technical Memoranda #29, #30, #31 - Management Issues to be Considered in Watershed Selection; Process and Objective Criteria for Incorporating Management Issues into the Selection of Watersheds; and Watershed Suite Selection and Reevaluation to the Core Group on April 18, In the memorandum, the work group describes their proposal for incorporating management issues in the prioritization of watersheds for assessment. Work Group D s efforts build on an early effort at developing a prioritization performed by Work Group C. Table 7 shows the ranking recommendations that emerged from Work Group C and Work Group D. F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 23

27 Table 7: SCBWMI Ranking of Watersheds Work Group C Tier One Criteria Based Question 1 Management Issue Based 1. San Francisquito Creek 1. Guadalupe River 2. Coyote Creek 2. San Francisquito Creek 3. Guadalupe River 3. Lower Coyote Creek 1 4. Stevens Creek 4. Stevens Creek 5. Arroyo La Laguna 5. Permanente Creek 6. Lower Penitencia / Berryessa Creeks 6. Upper Penitencia Creek 2 7. San Tomas Aquino Creek 7. Arroyo La Laguna 8. Calabazas Creek 8. Baylands 9. Adobe Creek 9. Calabazas Creek 10. Permanente Creek 10. Adobe Creek 11. Matadero/ Barron Creeks 11. Upper Coyote Creek 12. Sunnyvale East Channel 12. Lower Penitencia Creek 13. Sunnyvale West Channel 13. Matadero/ Barron Creeks 14. San Tomas Aquino Creek Baylands Sunnyvale East Channel 16. Sunnyvale West Channel 1 Work Group D considered Lower Coyote Creek (below Anderson Reservoir) separate from Upper Coyote Creek. 2 Upper Penitencia Creek was not ranked by Workgroup C; it was substituted for Lower Penitencia Creek in the first suite of watersheds selected for assessment. 3 Work Group C did not rank the Baylands as a separate watershed. RECOMMENDATIONS AND CONCLUSIONS Table 8 presents a summary of the criteria discussed in this report and the resulting rankings for each watershed. Based purely on a ranking of watershed characteristics, Coyote, Arroyo la Laguna, San Francisquito, Guadalupe, and Baylands are the top five priority watersheds. These are roughly consistent with the SCBWMI s highest priority rankings. Note that Arroyo la Laguna lies entirely within Alameda County. All other watersheds are part of Santa Clara County. Coyote has the lowest percentage of developed riparian corridor and imperviousness, and ranked second highest in projected development. Arroyo la Laguna ranks first in projected development. Sunnyvale East, Adobe, Calabazas and Sunnyvale West ranked low on the watershed characteristics based priority list because these watersheds are relatively built out, with some of the highest percentages of imperviousness and riparian corridor development in the watershed. Figures 2 through 5 illustrate these points as well. F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 24

28 Table 8. Summary of Prioritization Criteria and Considerations Watershed Imperviousness Rank Riparian Development Rank Projected Development Rank Total Rank Coyote Arroyo la Laguna San Francisquito Guadalupe Baylands Stevens Lower Penitencia San Tomas Matadero/Barron Permanente Sunnyvale West Calabazas Adobe Sunnyvale East Other considerations in assigning priority to these watersheds are pollutant specific concerns and assessment efforts by other agencies. Guadalupe s mercury TMDL and the San Francisquito sediment concerns provide support for assigning these two watersheds high priority. In addition, the WMI has begun assessment of its three pilot watersheds (Guadalupe, San Francisquito, and Upper Penitencia 11 ) and SCVURPPPhas initiated a pilot assessment for the Coyote. Using the three watershed characteristic criteria, with consideration given to pollutant specific concerns and the WMI s existing prioritization, the following prioritization is proposed: 11 Upper Penitencia is a subwatershed of Coyote F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 25

29 Table 9. Prioritization and Schedule of Santa Clara County Watersheds for SCVURPPP/SCBWMI Watershed Assessments Coyote Watershed 1 Notes Begin Assessment/Report to RB 2 Pilot Assessment underway Ongoing (includes field funded by SCVURPPP 3 monitoring and analysis already completed as part of WERF study see workplan for schedule Upper Penitencia SCBWMI pilot watershed Ongoing see workplan for schedule San Francisquito SCBWMI pilot watershed Ongoing see workplan for schedule Guadalupe SCBWMI Pilot Watershed Ongoing see workplan for schedule Baylands Stevens SCVURPPP initiated collection of data for incorporation into meta data matrix Ongoing see workplan for schedule Schedule and begin work after results of ongoing assessments are complete 2. Lower Penitencia San Tomas Matadero/Barron Permanente Sunnyvale West Calabazas Adobe Sunnyvale East 1 Arroyo la Laguna is not included on the Program s priority list because it lies entirely within Alameda County and is thus outside the jurisdiction of the Santa Clara Valley Urban Runoff Program. 2 As described in the five-year monitoring plan, the Program will evaluate the results of the existing and scheduled assessments and develop a plan for the remaining watersheds accordingly. 3 Selected portions of the Coyote watershed will be used to conduct the pilot assessment. The goal will be to rely on hose areas of the watershed where recent monitoring data are available that would allow for the analysis of the functional, RMAS and WMI assessment approaches. F:\SC26-41 INTEGRATION REPORT\INTEGRATIONV4.DOC 26