2005 Project Viability Assessment

Transcription

1 2005 Project Viability Assessment October 7, 2005

2 Contents ACRONYMS 1.0 EXECUTIVE SUMMARY PROJECT OVERVIEW PROJECT COMPONENTS KEY CHALLENGES PVA RESULTS, RISKS, AND BENEFITS COST PURPOSE PROJECT OVERVIEW THE CHALLENGE THE SOLUTION PROJECT COMPONENTS PROJECT BENEFITS CRITERIA FOR MOVING AHEAD STAKEHOLDER INVOLVEMENT STUDY AREAS TIMELINE WATER DEVELOPED OR CONSERVED (YIELD) RIVER WATER GROUNDWATER FOR AGRICULTURE AGRICULTURAL CONSERVATION FACILITY SITING (ENGINEERING) ENVIRONMENTAL ISSUES RIVER WATER QUALITY RIVER HABITAT BAY HEALTH PERMITTING REQUIREMENTS STUDY PERIOD COSTS IMPLEMENTATION PERIOD COSTS COST ESTIMATING METHODOLOGIES BASES OF COST ESTIMATES COST SUMMARY CONCLUSIONS REFERENCES ACKNOWLEDGEMENTS 02_FINALCONTENTS_SW.DOC LSW i

3 List of Tables 4-1 RESULTS FROM LSWP WATER AVAILABILITY ANALYSES KEY STAKEHOLDER ISSUES AND ENHANCEMENTS TO ADDRESS ISSUES COMPARISON OF MAXIMUM AVERAGE DRAWDOWNS PREDICTED BY IRRIGATION DISTRICT DELIVERY SYSTEM LOSSES AND POTENTIAL WATER SAVINGS IN LAKESIDE, GULF COAST, AND GARWOOD DISTRICTS PROJECTED ACREAGE AND ON-FARM WATER CONSERVATION FROM BMPS IN EACH IRRIGATION DISTRICT PROJECTED POTENTIAL CONSERVATION FROM ADOPTION OF A NEW RICE VARIETY PRELIMINARY SUMMARY OF WATER LOSSES AND POTENTIAL WATER SAVINGS PROJECTED STUDY PERIOD COSTS LSWP FACILITY SIZING FOR COST ASSUMPTIONS LSWP COST SUMMARY, YIELD OF 150,000 ACRE-FEET/YR List of Figures 1-1 PROJECT OVERVIEW SCHEDULE OVERVIEW OFF-CHANNEL STORAGE FACILITY OPERATION SCHEMATIC LOCATION OF THE IRRIGATION DISTRICTS AND THE IRRIGATED CROP ACREAGE IN 2000 IN STUDY AREA BASED ON NRCS MAPS POTENTIAL IMPEDIMENTS TO SITING IN PROJECT AREA, EXAMPLE OF MAPPED OIL AND GAS PIPELINES SAMPLE DIAGRAM OF OFF-CHANNEL STORAGE FACILITY UPPER MODEL SEGMENTS ON THE COLORADO RIVER MAP OF 10 INTENSIVE STUDY SITES EXAMPLE OF HABITAT MAPPING AT 10 INTENSIVE STUDY SITES CYCLEPTUS ELONGATUS - BLUE SUCKER COLUMBUS RIFFLE MATAGORDA BAY SYSTEM SCHEMATIC OF BAY HEALTH EVALUATION FRAMEWORK PRELIMINARY FUTURE JANUARY MONTHLY BAY INFLOWS WITHOUT AND WITH PROJECT PRELIMINARY FUTURE SEPTEMBER MONTHLY BAY INFLOWS WITHOUT AND WITH PROJECT MATAGORDA BAY SYSTEM MARCH CLASSIFICATIONS OYSTER REEF AND SEAGRASS DISTRIBUTION ABUNDANCE OF BROWN SHRIMP IN TPWD DATA, MARCH ABUNDANCE OF BROWN SHRIMP IN TPWD DATA, MAY OVERVIEW OF STUDY PERIOD COSTS LSWP COST SUMMARY, ANNUALIZED COST MODEL ANNUALIZED COST METHOD, COMPONENT COST CONTRIBUTIONS _FINALCONTENTS_SW.DOC ii

4 Acronyms AG B&E BMP DO DSM DPV EPA ET FEMA FINS GAMs GCD GCDs GIS GIWW GW IBT LCRA-SAWS LNVA LSWP NRCS O&M OCSFs PVA Rice WCA SAWS SCADA agricultural projects in Region K bay and estuary best management practice dissolved oxygen daily spreadsheet model Discounted Present Value model or method Environmental Protection Agency evapotranspiration Federal Emergency Management Agency Freshwater Inflow Needs Study Groundwater Availability Models Groundwater Conservation Districts Groundwater Conservation Districts Geographic Information System Gulf Intracoastal Waterway groundwater interbasin transfer Lower Colorado River Authority-San Antonio Water System Lower Neches Valley Authority Lower Colorado River Authority-San Antonio Water System Water Project Natural Resources Conservation Services operations and maintenance costs off-channel storage facilities Project Viability Assessment Rice Water Conservation Analysis San Antonio Water System supervisory control and data acquisition 03_FINALACRONYMS_SW.DOC LSW

5 SRP TAES TCEQ TPWD TWDB USACE USDA USFWS USGS WAM WID WMP WTP Science Review Panel Texas Agricultural Experiment Station Texas Commission on Environmental Quality Texas Parks and Wildlife Department Texas Water Development Board United States Army Corps of Engineers United States Department of Agriculture United States Fish and Wildlife Services United States Geological Survey Water Availability Model Water Improvement District Water Management Plan Water Treatment Plant 03_FINALACRONYMS_SW.DOC 2

6 1.0 Executive Summary Project Overview The Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project would conserve and develop up to 330,000 acre-feet of water per year (an acre-foot equals 325,851 gallons). Of that, approximately 180,000 acre-feet per year of agricultural and other rural water needs would be met in the Colorado basin through conservation of agricultural irrigation water, storage of river water, and supplemental groundwater for agricultural use. Up to 150,000 acre-feet per year of river water would be transferred to the San Antonio area for the term of the Agreement. Groundwater would not be transferred to San Antonio as part of the Project. Figure 1-1 provides an overview of the project. FIGURE 1-1 Project Overview Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project This collaborative Project would provide a model for trans-basin projects that are environmentally sustainable and protect both rural and urban economies. An overview of the Project schedule is provided in Figure _FINAL2005PVA SEC1_SW.DOC LSW

7 FIGURE 1-2 Schedule Overview Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Project Components The LCRA-SAWS Water Project (LSWP) includes the following components: Building off-channel storage in the lower Colorado River basin, allowing up to 150,000 acre-feet of river water per year to be available for transfer to the San Antonio area. Implementing additional water conservation measures for rice farmers in Colorado, Wharton, and Matagorda counties would lower demand. At least 118,000 acre-feet per year could be conserved by a combination of delivery system improvements and on-farm water saving measures. Using groundwater conjunctively with river water for agriculture in the lower Colorado River basin when river water is insufficient. The Definitive Agreement between LCRA and SAWS limits groundwater use to a maximum annual average of 36,000 acre-feet of groundwater during the term of the Implementation Period, a maximum 10-year rolling average of 62,000 acre-feet per year, and a maximum annual usage equal to or less than 95,000 acre-feet. Anticipating environmental needs in light of growing populations in the lower Colorado River basin and the San Antonio area, the Project will ensure that adequate amounts of water continue to flow in the Colorado River and into Matagorda Bay. A fifth component, outside the scope of the studies described in this PVA, but essential to ultimate delivery of the water, is the water transmission and treatment system that will pipe the river water from the LCRA boundary to the San Antonio area and treat it to meet drinking water standards. This portion of the overall Project will be studied, developed and managed by SAWS. 04_FINAL2005PVA SEC1_SW.DOC 1-2

8 In combination, the Project allows Highland Lake levels to remain higher than without the Project. Key Challenges Key challenges being addressed as part of the LSWP studies include the following. River water (surface water) availability Groundwater for agriculture Agricultural conservation in irrigation districts Facility siting and design Colorado River and off-channel storage water quality Colorado River habitat Matagorda Bay health Social and economic and environmental benefits and costs Permitting requirements and processes Cost The Definitive Agreement between LCRA and SAWS provides the fundamental framework for shared risk on the Project. The division of risk is characterized by the following: During the Study Period, LCRA or SAWS may withdraw from the Project under varying conditions and, if so, the costs incurred to date would be evenly divided between the two entities. At the conclusion of the Study Period, if SAWS approves the LCRA developed Implementation Plan outlining in detail the Project cost and water yield, then LCRA is obligated to deliver the agreed amount of firm water to SAWS according to, and for the term of, the contract. PVA Results, Risks, and Benefits River Water Availability Studies continue to refine how the various sources of water available to LCRA can be effectively used as a system to meet future water needs both inside and outside the lower Colorado River basin. The results to date increase confidence in the availability of river water to support the LSWP and the transfer of up to 150,000 acre-feet per year to SAWS. Some highlights of the preliminary results of this ongoing analysis (scheduled for completion in 2007) are summarized below. Projected year-2060 demands for agricultural irrigation water in the lower basin would be satisfied. Critical instream flow criteria (for drought protection of aquatic life) in the lower Colorado River are expected to be satisfied almost all the time with or without the LSWP in operation. 04_FINAL2005PVA SEC1_SW.DOC 1-3

9 Criteria for freshwater inflow to Matagorda Bay from the Colorado River are expected to be satisfied slightly more often with the LSWP in operation. Critical and target criteria for freshwater inflows to Matagorda Bay from the Colorado River, subject to the multi-year caps stipulated in the 2003 WMP now pending approval before TCEQ, are expected to be satisfied slightly more often with the LSWP in operation. Storage in Lakes Buchanan and Travis and the associated lake levels are projected to be higher with the LSWP implemented compared to the base case without the Project in operation, as required by the enacting legislation for the Project. Key risks and potential benefits associated with this aspect of the study include the following: Similar to all other water supply planning projects in the state, there is a risk that conditions more severe than the drought of record could occur during the life of the Project. According to state law, in these situations, customer curtailment is generally required on a pro rata basis, according to the terms of their contracts. The Project will involve optimization of the entire LCRA water rights system, providing a more efficient system better able to meet basin needs in the long-term. There is a risk associated with the assumption of the amount of return flows that will be available for use by downstream water rights holders. For example, the return flow estimates for the City of Austin used in the modeling, which reflect the Region K planning projections provided by the City, could change pending outcome of the City s existing permit application requesting control of return flows in the river. The demands used in this modeling effort are the best available information at this time and are consistent with those being used by water planners in Region K. An area of uncertainty pertains to future requirements for environmental flows to support both instream river uses and bay resources. The water availability analyses of the LSWP have incorporated the basic environmental flow requirements and criteria included in the pending 2003 Water Management Plan for the lower Colorado River basin, with some minor modifications to better reflect anticipated future conditions. While these provide considerable protection to both instream and bay and estuary (B&E) uses, refinements to these requirements are continually being considered as new studies are undertaken that produce new information, including the studies associated with this Project. Groundwater for Agriculture The Groundwater study is designed to help model the effect of the LSWP on aquifers and to design and locate wells in an optimal manner. Some highlights of this ongoing analysis (scheduled for completion in 2007) are summarized below. A groundwater model is being developed to refine elements of the two applicable regional Groundwater Availability Models (GAMs) to address key stakeholder feedback and concerns regarding pumping, vertical resolution (the way the model distinguishes among layers in an aquifer), recharge, water quality, aquifer properties, and land subsidence. A refined model is under development; however, current analyses using the existing local GAMs continue to show that groundwater should be available in the amounts and within the constraints defined in the Definitive Agreement. 04_FINAL2005PVA SEC1_SW.DOC 1-4

10 There are potential risks and benefits associated with the groundwater aspect of the Project. One potential benefit is that the much more detailed model and associated optimization tools developed for the Project could allow water well placement and operation that achieves target yields with even less drawdown than predicted with the GAM runs. On the other hand, if the more detailed model identifies additional potential impacts such as subsidence or changes to water quality, then production volumes and/or mitigation costs could change for the Project. The groundwater study is being conducted to help minimize impacts to groundwater. Impacts identified and mitigation needed will be detailed in the studies and resulting Implementation Plan. Another potential risk is evolving groundwater legislation and the potential for changes in the statutory authorities relating to groundwater management and regulation. Agricultural Conservation The Agricultural Conservation study is focused on identifying potential water conservation measures within the delivery systems as well as on the individual farms served by irrigation districts in the lower Colorado River basin. Preliminary estimates indicate that approximately 125,000 acre-feet per year of savings is potentially available; therefore, projections of the reduced water demand of 118,000 acre-feet per year previously calculated for the Project is achievable. Some highlights of this ongoing analysis (scheduled for completion in 2007 with the exception of the new rice variety research) are summarized below. Total potentially available savings from improvements in the irrigation delivery systems are estimated at about 48,000 acre-feet per year, on-farm savings 45,200 acre-feet per year, and new rice varieties 32,000 acre-feet per year; thus, the estimated 118,000 acre-feet per year of conservation is expected to be achievable. A vegetation control program has the opportunity to conserve water by decreasing the evapotranspiration by invasive plants along the canal banks and levees. Neither seepage into the soil nor evaporation appears to be a significant source of water loss in the canals. Both overflow points in the system (spills) and canal breaks and leaks appear to be significant sources of water loss. A supervisory control and data acquisition (SCADA) system that controls and monitors the canal operations has the potential to conserve water. Research in the development of a high yielding rice variety that could result in water conservation is ongoing and will be complete by 2010; calculations of estimated potential savings will be confirmed later during the Study Period. The following risks are identified for improving water use efficiency for either the delivery systems or on-farm usage. Changes to delivery system operation, such as reduced inspections or deferred maintenance, could increase leakage and system losses. Changes in ownership, federal cost-share programs, operator training, or other factors could cause lower than expected rate of on-farm conservation practices. 04_FINAL2005PVA SEC1_SW.DOC 1-5

11 Increases in acreage irrigated or number of annual crops per acre due to changes in the global rice economy may increase overall water demand, even though efficient water use practices are followed. Water conserving rice varieties may take longer to develop than expected or farmers may be slower to adopt the new varieties if they are concerned about quality, marketability, or other characteristics. Facility Siting Facilities such as off-channel storage, pipelines, intakes, and pump stations are needed to implement the LSWP. The 2005 work effort is designed to assess potential sites for the major Project component facilities. Some highlights of this ongoing study (scheduled for completion in 2007 after extensive public involvement) are summarized below. Constraints maps, identifying areas where facilities might be compatible with existing land uses based on technical criteria, were prepared to guide the siting process. The Geographic Information System (GIS) data maps existing land uses, threatened and endangered species habitat, existing utilities, wetlands, known cultural and historical resources, oil and gas wells and pipelines, floodplains, parks, etc. The largest sites needed are for the off-channel storage facilities (OCSFs), which conceptually range in size from approximately 1,000 acres to 8,000 acres. Conceptual facility sizes and designs were developed working with the river water availability portion of the study, which defined diversion rate characteristics and storage volume scenarios for costing purposes. There are potential risks and benefits associated with facility siting aspects of the Project. As the studies progress, more detailed daily river modeling information may allow more efficient design of facilities, potentially reducing costs. On the other hand, design issues (i.e., sub-surface soil conditions) may be identified that increase costs. The field assessment of preferred sites later in the study may identify environmental, cultural, or other constraints not previously identified. Fortunately, alternative sites are numerous, which will help manage this risk. As with any infrastructure project involving land acquisition, sites preferred for technical, environmental or cost reasons may or may not be offered for sale by one or more willing sellers. In addition, the purchase of these sites will not occur until the Implementation Plan is approved by SAWS after This could affect the cost and suitability of these preferred sites in the future. River Water Quality The goal of the Water Quality Studies during 2005 is to collect data from various segments of the lower Colorado River and refine water quality models to both estimate potential changes in water quality that could result from the LSWP as well as to shape the design and operation of the LSWP. Once completed, this information will be used by biologists studying aquatic habitat as well as the Matagorda Bay and estuary system to predict potential effects on the 04_FINAL2005PVA SEC1_SW.DOC 1-6

12 flora and fauna of those systems. Results of the studies will also support design of treatment facilities and processes to ensure drinking water standards are met. Some highlights of the ongoing analyses (scheduled for completion in 2006) are summarized below. The river water quality model used by the Texas Commission on Environmental Quality (TCEQ), named QUAL-TX, was extended from its traditional end point at Smithville to Bay City. A series of field studies (e.g., dye tracing and low flow sampling) are helping to improve and calibrate the model. Based on the existing data and calibration, no water quality concerns have yet been identified in the river below Smithville. Because the section of the river between Austin and Smithville has the highest volumes of wastewater discharges, it is the reach most likely to experience potential changes in water quality if the river flow regime changes. For the 2004 PVA, a water quality analysis was performed (Chapter 5) using the TCEQ QUAL-TX model available at that time, with specific modifications to approximate summertime conditions. Since the finalization of the 2004 PVA, TCEQ has modified several characteristics of the input files to their QUAL-TX model of the lower Colorado River. This new QUAL-TX model, coupled with the changes implemented for the 2004 PVA, generates a similar overall result to the model version used in the 2004 PVA. Therefore, the recent changes to the TCEQ QUAL-TX model do not appear to change the results of Chapter 5 of the 2004 PVA. The water quality studies associated with the LSWP are intended to increase the understanding of the existing conditions in the lower Colorado River, predict possible changes to those conditions, and assess the likely result that those changes could have on water quality. An analysis will be performed with the model to quantify uncertainties inherent in the model, inputs and outputs. Potential risks (and benefits) related to water quality include the following: Because operation of the LSWP may result in lower Highland Lake releases to meet downstream irrigation needs during the summer months, low-flow conditions could exist when temperatures are higher. While this is a more natural condition in rivers without upstream reservoirs, it could result in decreased levels of dissolved oxygen and potentially increased levels of nutrients in the river resulting from wastewater discharges during low-flow conditions. Changes in regulations or wastewater discharge permits limits could affect water quality. Better water clarity resulting from lower flows during the spring spawning season could benefit reproduction of aquatic species such as the blue sucker. River Habitat The LSWP has the potential to alter the flow regime for the lower Colorado River. As with any change of this type on a controlled (dammed) river system, the ecosystem can be affected both positively and negatively. The study team is therefore developing ecologically based tools, or models, to help predict the effects of a full range of flows on the ecology of the lower Colorado River system. Some highlights of this ongoing analysis (scheduled for completion in 2007) are summarized below. 04_FINAL2005PVA SEC1_SW.DOC 1-7

13 The study team has visited ten intensive survey sites several times to document river shape and structure (geomorphology), evaluate habitat, and sample aquatic species present. The sites were selected in 2004 as representative of the various reaches and habitats in the river from below Austin to Matagorda Bay. The study team has begun developing models to relate river flow to quantity and quality of aquatic habitat. The 30 blue suckers (state-listed threatened species in the Colorado River basin) that were tagged with radio transmitters in 2004 have been tracked. Upstream movement of over 170 river miles was observed during the spring. The team observed and videotaped spawning of approximately 40 to 50 blue suckers below Longhorn Dam in Austin during March, when flows and water depth were appropriate for spawning. These observations provide significant detail about key habitat conditions needed by the species. Larval and juvenile blue suckers have been difficult to locate and collect (through June 2005) as reported in other river basins. Alterations to flow regime can be potentially beneficial or detrimental to various species depending on how changes to flow depth, velocity, and timing affect available habitat for different species, including the blue sucker. In addition, changes may affect the life stages of each species differently. LSWP facilities and structures could impede adult blue sucker migration on the river. Alternately, the results of the study will provide information that helps design facilities that protect fish passage. Matagorda Bay Health The principal charge for the Matagorda Bay Health Evaluation study is to assess the environmental effects that could result from changes in freshwater inflow patterns to the bay because of the LSWP. While this is a complex undertaking, significant progress has been made in 2004 and Some highlights of this ongoing analysis (scheduled for completion in late 2006) are summarized below. The approach for measuring bay health, termed the Bay Health Framework, was developed by the study team. The framework was favorably received by the Science Review Panel (SRP) and key agencies. Important physical, chemical, and biological data regarding the bay have been collected and organized for use in the analyses. The model for predicting salinity in the various areas of the bay was selected, and development of the model has begun. Model development is anticipated to be complete by mid Preliminary habitat maps have been developed for the bay, in particular the Texas Parks and Wildlife Department (TPWD) Coastal Fisheries Data, and biological data are being statistically analyzed. There are potential risks and benefits associated with the bay health aspect of the Project. 04_FINAL2005PVA SEC1_SW.DOC 1-8

14 The bay system is complex and the proposed framework looks at the bay from a number of different perspectives, therefore it is likely that the results will not provide simple guidance for decision-makers and regulatory agencies. The approach allows evaluation of inflows from both the river and the coastal basins. The coastal basins appear to receive a portion of their flow from rice irrigation. These irrigation-related inflows could decrease if rice farming were to decline in the region (possibly due to lack of water without the Project), or if agricultural conservation measures are so successful that less water is contributed to the bay through irrigation return flows. Permitting Requirements During the development of the Study Period Plan, key local, state, and federal permits required for implementation of the Project were identified. The major permits for the Project include: Water rights permits or amendments (including interbasin transfer permit), under the jurisdiction of TCEQ Section 404/10 permit under the Clean Water Act, under the jurisdiction of United States Army Corps of Engineers (USACE) Permits for construction and operation of groundwater wells, under the jurisdiction of the Groundwater Conservation Districts (GCDs). Work to date continues to indicate that all necessary permits are obtainable. Some highlights of the ongoing permitting activities (scheduled for target completion date in 2010) are summarized below. Each of the technical studies were reviewed and refined to ensure that permitting requirements are met by the individual study teams. During 2005, the permitting efforts focused upon pre-application coordination with key local, state, and federal agencies. Economic assessments have begun to address requirements for state and federal permitting processes as well as required legislative findings that the LSWP will protect and benefit water users within the lower Colorado River watershed and the LCRA service area. A preliminary submittal to the Galveston District of USACE received a response indicating their role as the lead district for the federal permitting. Subsequent meetings indicate that the USACE may request a joint permit application. While this issue is yet to be resolved, if this approach is used the USACE would likely delineate LCRA s and SAWS respective responsibilities within the permit or permits. The USACE also indicated that additional detailed information from the ongoing studies in the form of a draft permit application would be needed to determine whether an Environmental Assessment or Environmental Impact Statement would be required. There are potential risks and benefits associated with permitting the Project. 04_FINAL2005PVA SEC1_SW.DOC 1-9

15 Water rights and interbasin transfer permits from TCEQ could be affected or their issuance be delayed by a number of factors, including ongoing litigation on water rights, other pending water right application processes, environmental flow issues, and others. Although indications are that the federal Section 404/10 permits can be obtained, the schedule for federal permitting could be affected by delays in the USACE decision regarding the level of environmental documentation they will require for the Project. The program is working closely with the GCDs to provide to the GCDs the information they need to prepare and issue operating and production permits. Cost An update of the cost estimate for the LSWP at 150,000 acre-foot per year yield to San Antonio resulted in similar results to the 2004 PVA, with the exception that the unit costs used to develop the estimate were inflated from 2002 to 2004 dollars for the 2005 PVA. Using the state s regional planning cost methodology or Annualized Cost Model, using 2004 dollars, the Project costs range from $957 to $1,135 per acre-foot per year, depending upon off-channel storage facility location. Note the cost estimates include the facilities in the lower Colorado River basin (Region K) and in the San Antonio area (Region L), but NOT costs associated with integration into the SAWS distribution system. The LSWP cost estimate in the 2005 PVA was updated from the 2004 PVA to include the following more current information: Conceptual design and sizes for Project components and associated facilities Refined water pipe and pump station sizes and routes based on a preliminary hydraulic model and engineering analysis Addition of 25,000 acre-feet of storage at the end of the pipeline at or near Bexar County Draft Region L Water Plan unit costs serve as the cost basis for this estimate, with the exception that they are updated from 2nd Quarter 2002 dollars to 2nd Quarter 2004 dollars Capital costs include construction costs, engineering, legal, financing, bond counsel, contingencies, survey, land acquisition costs, environmental mitigation, study period costs, and relocation of conflicting facilities such as roads, oil and gas pipelines, and irrigation canals. This cost analysis is neither a socioeconomic nor a benefit-cost analysis and it is not intended to reflect a construction cost estimate for the proposed facilities. Rather, costs are presented using Region L Water Plan unit costs for consistency and the same costing methodology. Annual costs include operations and maintenance costs (O&M), power costs, and when applicable, reservation and/or purchase fees for water. Ultimate actual costs of the Project will change from estimates made at this early stage of the studies, resulting from a number of factors such as inflation, materials costs, final configuration and size of Project components. Therefore, updated and refined engineering estimates will be prepared annually per the Definitive Agreement between SAWS and LCRA. Following are some of the risks or variables related to cost. 04_FINAL2005PVA SEC1_SW.DOC 1-10

16 Materials Price Inflation (greater than general inflation) and energy cost increases could affect the final implementation costs, as will the actual financing costs and interest rates associated with construction of various project components. Cost estimates (cost per acre foot) could rise or fall substantially, based on modeling of river water availability because unit costs are highly sensitive to annual yield calculations. Study efforts could reveal unforeseen site constraints, substantially increasing costs and possibly eliminating some alternatives from consideration. Because the fundamental assumptions for this analysis are the same as those used in the Region L planning process, if those unit costs differ substantially from actual costs then the evaluations in this assessment would be similarly inaccurate. The annualized method is a snapshot of costs and does not include the potential increases in costs such as energy and operations over time. 04_FINAL2005PVA SEC1_SW.DOC 1-11

17 2.0 Purpose The purpose of the Project Viability Assessment (PVA) is to evaluate the technical, environmental and economic feasibility of the LCRA-SAWS Water Project (LSWP) based on the information learned to date during the Study Period. Key activities and study findings are summarized, and interrelationships and dependencies between studies are highlighted. The PVA also summarizes potential risks and benefits associated with development and/or operation of the Project. While at this time these risk/benefit summaries are general in nature, more specific information will be available as the studies progress. The assessments in the PVA focus on a fifty year planning horizon, through 2060, consistent with the projections and evaluations of the state s regional planning process. The study activities planned for 2006 will significantly advance the modeling efforts to refine project water conservation and development estimates, environmental requirements and effects, and project costs. Studies began in July 2004 to address key issues associated with the Project, such as water quality, potential environmental effects, cost, and implementation of conservation and water supply development methods. The 2004 PVA provided an update of the Project information originally developed in the state s regional water planning process. It also evaluated those factors most likely to affect the feasibility of the Project based on the limited results from the first year of the Study Period. The 2005 PVA focuses on the following: Project overview Section 3 Water developed or conserved (Yield) Section 4 Facility siting (Engineering) Section 5 Environmental and permitting issues Sections 6 and 7 Study and Implementation Period costs Sections 8 and 9 05_FINAL2005PVA SEC2_SW.DOC LSW

18 3.0 Project Overview The Challenge San Antonio and the lower Colorado River basin both face long-term water shortages by Agriculture in the lower Colorado River basin could lack about one third to one half of estimated water needs. Region K foresees a shortage of water for rural communities upstream of Austin and the Highland Lakes (Llano and Goldthwaite). The population in Bexar County is expected to nearly double by 2060, although due to aggressive conservation, municipal water demand is expected to be only 150 percent of today s use. The Solution The Lower Colorado River Authority (LCRA) and the San Antonio Water System (SAWS) have partnered to conserve and develop water for San Antonio and the lower Colorado River basin in the 21 st century. These two neighboring regions have developed a potential water management project to provide ample and reliable water for the long term while protecting the environment. LCRA and SAWS are currently studying the feasibility of the Project. The LCRA-SAWS Water Project (LSWP) would conserve and develop up to 330,000 acre-feet of water per year (an acre-foot equals 325,851 gallons). Of that, approximately 180,000 acrefeet per year of agricultural and other rural water needs may be met in the Colorado basin through conservation of agricultural irrigation water, storage of river water, and use of supplemental groundwater for agricultural use. Up to 150,000 acre-feet per year of river water would be transferred to the San Antonio area through off-channel storage. Groundwater would not be transferred to San Antonio as part of the Project. This collaborative Project would provide a model for trans-basin projects that are environmentally sustainable and protect both rural and urban economies. Project Components The LSWP includes the following components: Building off-channel storage in the lower Colorado River basin, allowing up to 150,000 acre-feet of river water per year to be available for transfer to the San Antonio area. Implementing water conservation measures for rice farmers in Colorado, Wharton, and Matagorda counties would lower demand. The Project has estimated that at least 118,000 acre-feet per year could be conserved by a combination of delivery system improvements and on-farm water savings. Using groundwater conjunctively with river water for agriculture in the lower Colorado River basin when river water is insufficient would make available a maximum annual 06_FINAL2005PVA SEC3_SW.DOC LSW

19 average of 36,000 acre-feet of groundwater during the term of the Implementation Period, a maximum 10-year rolling average of 62,000 acre-feet per year, and a maximum annual usage equal to or less than 95,000 acre-feet to agriculture during the entire implementation period. Anticipating environmental needs in light of growing populations in the lower Colorado River basin and the San Antonio area, the Project would ensure that adequate amounts of water continue to flow in the Colorado River and into Matagorda Bay to sustain the environmental health and productivity of those habitats. A fifth component, outside the scope of this assessment but essential to ultimate delivery of the water, is the water transmission and treatment system that will pipe the surface water from the LCRA boundary to the San Antonio area and treat it to meet drinking water standards. This portion of the overall Project will be managed by SAWS. In combination, the Project allows Highland Lake levels to remain higher than without the Project. Project Benefits If constructed, the LSWP would benefit both regions by accomplishing the following goals: Supply long-term, high-quality, reliable water to the San Antonio area. Minimize irrigation water shortages currently predicted for agricultural water needs in the lower Colorado River basin. Keep freshwater inflows into Matagorda Bay at adequate levels to maintain its health and productivity. Protect Colorado River instream-flow. Sustain higher water levels in Lake Buchanan and Lake Travis. Provide water that can be used by rural communities above the Highland Lakes. Criteria for Moving Ahead Throughout the technical studies, LCRA and SAWS will evaluate the Project s viability on an ongoing basis. Specific legislative criteria (Texas Water Code, ) must be met before any water is transferred from the Colorado basin. These include the following requirements: Colorado River basin interests must benefit and be protected. Freshwater inflows into Matagorda Bay must be adequate to maintain its health and productivity. Colorado River instream-flow protection must be provided. A broad public and scientific review process must take place. San Antonio must continue to practice stringent conservation measures. Water levels in Lake Travis and Lake Buchanan must benefit. The Project must be consistent with Texas regional water plans. In addition, the Project must be cost-effective for the citizens of San Antonio. If SAWS determines during its Implementation Plan review or its annual Project Plan review that costs 06_FINAL2005PVA SEC3_SW.DOC 3-2

20 do not meet SAWS criteria, if there is not sufficient water to meet needs in both/either basin, or if environmental requirements are not met, the Project will not move ahead. SAWS is funding the Project based on its Agreement with LCRA. During the Study Period, if a decision is made not to proceed, the costs incurred up to that point will be shared equally by SAWS and LCRA. The Boards of each agency review the status of the feasibility studies through various means including this Project Viability Assessment as a key source of information during the decision-making process. Stakeholder Involvement Stakeholder involvement and public outreach are high priorities for the LSWP. Rigorous and meaningful involvement that incorporates feedback about the Project and the work processes and approaches during the Study Period will result in higher quality analyses and, ultimately, a better Project. In 2002 and 2003, stakeholders actively participated in the development of the Study Period Plan, which was used to guide the studies that began in In 2005, efforts accelerated to involve stakeholders those most directly affected by the Project as well as interested citizens and the public. Key audiences were involved through meetings organized by the project team to focus specifically on this Project as well as affiliate groups of LCRA and SAWS, such as standing citizen advisory panels. In addition, the project team has cultivated media relations with selected news organizations to assist in the broad distribution of information. These efforts have helped to expand the understanding of the Project, increase awareness of it, and improve technical study methodologies to focus on issues of importance to stakeholders, state and federal resource agencies, and the public. Notable achievements in 2005 include the following: 150 percent increase in Technical Advisory Group membership from January to July 2005 Creation of three sub-advisory groups focusing on groundwater, agricultural conservation, and bay health 250 percent increase in Web site traffic from January to July percent increase in stakeholder and public meetings to a total of 16 in 2005 over the previous year, including the following: o o o o o three advisory group meetings five sub-advisory group meetings three farmer advisory group meetings four public outreach meetings one meeting with public officials Creation of stakeholder feedback process for incorporating public comments on the Project Viability Assessment into work processes Updated informational materials including brochure, executive summary, fact sheet, and presentations 06_FINAL2005PVA SEC3_SW.DOC 3-3

21 Looking ahead, the Project s goals with regards to stakeholder involvement are to widen public outreach, expand sub-advisory group efforts, and further upgrade briefing materials about the LSWP. Study Areas The project team, public advisory groups, and scientific review panel spent about a year developing a comprehensive Study Period Plan for the Project, which was approved by both the LCRA and SAWS Boards in The studies are designed to ensure that legislative criteria, technical and permitting requirements, as well as other concerns are fully explored, and to address these key issues: Agricultural conservation in irrigation districts Groundwater for agriculture Colorado River and off-stream storage water quality Colorado River flow relationships to habitat State threatened species (such as the blue sucker fish) Matagorda Bay health (general ecological issues and commercial and sport species) River water (surface water) availability Facility siting and design Social and economic benefits and costs Permitting processes required for implementation Timeline 1997 State-mandated regional water planning process initiated that gave rise to the idea for the Project Legislation adopted to allow the Project if certain criteria are met Definitive Agreement between LCRA and SAWS executed, followed by public involvement and independent scientific review which helped define the Study Period Plan Technical studies began to address environmental, cost, yield and socioeconomic aspects of the Project to meet feasibility, permitting and legislative needs Permitting processes begin. Studies substantially completed Studies, preliminary engineering and implementation plan currently scheduled to be finished Implementation Period Begins. Design and construction could begin as early as 2010 if LCRA finds that the Project protects the environment and benefits the basin, and SAWS finds the water volume, timing, and cost are acceptable and decides to move forward with the Project Water could be delivered to the San Antonio area Implementation Period ends; SAWS can elect to extend for an additional 30 years. 06_FINAL2005PVA SEC3_SW.DOC 3-4

22 "# $ % $$ & "# $$ "# $ "# '())))$$ $* "# $$+ $,)-) $ './)'..0'.() 123 4"#56 $ "78$3"784 $9394"# 6 :9$ #$ ## $5,)); :9 "#5 6"#+$$3 4 3$$$4: "$" <$$ $$,))-,)); $ 3+/'4:

23 ="# 6$< :$ * */ $& 3+/'4 "# $ % & " # $$% & $ # ' $# $ + > $ 3$,())) 4$ > "$ $"#5$ $$ "9 $3 4$ 6$ 6 $?:"#

24 "#5 $ :* "#5 $$ ' ( ' $"#$$ 9 "78$ $"#$ $ 6+@$ 9 :$ $,)-) $$$,))-,)); $$= A B123*4$ $$$&6 %"#>>$ $ "#$$ : "#"#9<>"$ %<B'9$$ $ #C#+ D "$5 $#C D+,)-): "$ $'/()))$ "#,;())$ $"$5+$: $'';())$ $ : 1 6 "$5"785 $ % +"# $$ $6 * = $+ $$6 $ $6 "#,)-) 1 The availability of return flows in the river will be affected by TCEQ s pending decision on the City of Austin s requests to retain rights to its return flows, which are the subject of a protest by LCRA and several others. (

25 "#5$$#C,))-,)); =,)-) '())))$ $"# "$" $ "#5 $ "#5"78 6'())))$ $$ $ :$"#5 $,)-)$ $#C D $"#: $()))$ $,)-) "#5:$,)-) $ ''0)))$ $,';)))$ % $"# = "#--;()$ $ $$ $"#$ $"78 ="#5 :+ $$ $,())))$ = $"78 "# 2 $= $ '())))$ $$$%$,())))$ $,())))$ $,())))$% 6 :% ="# 0))))$= $"#5"$ $.))))$= 2 Of the 250,000 acre-feet per year of water rights assigned to the LSWP, approximately 70,000 acre-feet per year of the authorized diversions under the Gulf Coast right are utilized only during the April-September period, which is a limitation that originates from provisions in LCRA s contract with the South Texas Project. The imposition of this limitation for the year-2060 analyses of the LSWP, however, is conservative because LCRA s contract with the South Texas Project expires in 2030.

26 "#5 65 3%>4"# "#$: $ "78$>$ $ :$$ =$ $ :"#5 "# ')$-,)))$ *.())) %-))) 6 "#5 6"#5 $ =$$:$,)-)3 4"#5 6?$,)-)$> : ;(.)))+: '')/))) $$'0-))) $ #C %*6$,))9"# 394 $,)-)$ $ >$3E'04F$'$ $ : $3 4,))9,))-,)); % $$3>G74* 6$,))9 $,)-)$ >$ ''F$'$$ $>$ ';F$'$$ : $,))9+$ $+%B$3+%B4

27 ,))-,)); %*6 * "#9 $$ 9 "#5 9,))-,)); +"#$"#5 :$ =* 6$9,))-,)); +"#5 >G7 '..,%+ $'..;+%B$$,))-,)); ' ( 9 $,)-)3 %4 +@ $,)-) $*,()))) = /' 3',)46 3,'.4"#3/)((4 3(--(4>G73--;4 )

28 ) ' * + % & * +, + ' - $. $$% % + + ROW PARAMETER UNITS BASE W/O LSWP PROJECTED WITH LSWP LSWP OPERATIONS (Based on Daily Spreadsheet Model) 1 Annual Water Delivery to SAWS ac-ft/yr n/a 150,000 2 Maximum Off-Channel Storage Capacity ac-ft n/a 250,000 3 Maximum Off-Channel Storage Surface Area acres n/a 6,615 4 Average Depth of Off-Channel Storage feet n/a Maximum Daily River Pumping Rate cfs n/a 2,400 6 Average Daily River Pumping Rate cfs n/a Minimum Daily River Pumping Rate cfs n/a 0 8 Percent of Time River Pumps in Operation % n/a Percent of Time at Maximum Pumping Rate % n/a Maximum Annual River Diversion Amount ac-ft/yr n/a 403, Average Annual River Diversion Amount ac-ft/yr n/a 145, Maximum Annual Highland Lakes Backup ac-ft/yr n/a 148, Average Annual Highland Lakes Backup ac-ft/yr n/a 16, Drought-Averaged Highland Lakes Backup ac-ft/yr n/a 69, Average Volume of Off-Channel Storage ac-ft n/a 162, Minimum Volume of Off-Channel Storage ac-ft n/a 0 17 Percent of Time Off-Channel Storage Full % n/a Percent of Time Off-Channel Storage Empty % n/a Average Off-Channel Storage Evaporation Loss ac-ft/yr n/a 7, Average Off-Channel Storage Seepage Loss ac-ft/yr n/a 5,000 HIGHLAND LAKES CONDITIONS (Based on WAM simulations) 21 Average Storage in Lake Buchanan ac-ft 561, , Average Storage in Lake Travis ac-ft 936, , Average Storage in Buchanan-Travis System ac-ft 1,497,299 1,616, Minimum Storage in Buchanan-Travis System ac-ft 9, , Average Lake Buchanan Level Increase for <90% Full feet n/a Average Lake Travis Level Increase for <90% Full feet n/a Average Lake Buchanan Level Increase for Drought feet n/a Average Lake Travis Level Increase for Drought feet n/a Average Annual System Evaporation Loss ac-ft/yr 75,948 82, Drought-Averaged System Evaporation Loss ac-ft/yr 74,382 97, Total Annual Fixed 2060 Demands on System ac-ft/yr 254, , Average Annual Backup Demands on System ac-ft/yr 48,196 53, Drought-Averaged Backup Demands on System ac-ft/yr 111, , Average Annual Interruptible Water Supplied ac-ft/yr 42,637 15, Drought-Averaged Interruptible Water Supplied ac-ft/yr 60,283 9, Average Annual Instream Environmental Flows Supplied ac-ft/yr 11,316 12, Drought-Averaged Instream Environmental Flows Supplied ac-ft/yr 20,795 19, Average Annual B&E Environmental Inflows Supplied ac-ft/yr 60,733 68, Drought-Averaged B&E Environmental Inflows Supplied ac-ft/yr 18,364 17,366

29 ) ' * + % &, ) ", $ % * +, + ' - $. $$% % + + ROW PARAMETER UNITS BASE W/O LSWP PROJECTED WITH LSWP LCRA AGRICULTURAL IRRIGATION DEMANDS (Based on WAM simulations) 40 Projected Year-2060 Total Irrigation Demands ac-ft/yr 335, , Percent of Time Annual Demand Fully Satisfied % Percent of Time >95% of Annual Demand Fully Satisfied % Percent of Time >90% of Annual Demand Fully Satisfied % Percent of Time No Supply Available % Percent of Total Demand Met for Period of Record % 90.7% 100.0% 46 Percent of Total Demand Met during Critical Drought Period % 73.3% 100.0% 47 Average Annual Supply from Colorado River Rights ac-ft/yr 271, , Drought-Averaged Supply from Colorado River Rights ac-ft/yr 186, , Average Annual Supply from Groundwater ac-ft/yr n/a 35, Drought-Averaged Supply from Groundwater ac-ft/yr n/a 61, Maximum Amount Supplied by Groundwater ac-ft/yr n/a 95, Average Annual Supply from Interruptible Water ac-ft/yr 32,716 1, Drought-Averaged Supply from Interruptible Water ac-ft/yr 59,598 7, Total Average Annual Irrigation Supply from All Sources ac-ft/yr 304, , Total Minimun Annual Irrigation Supply from All Sources ac-ft/yr 0 217,850 INSTREAM ENVIRONMENTAL FLOWS (Based on WAM simulations) 56 Average Annual Contribution from Highland Lakes ac-ft/yr 11,316 12, Drought-Averaged Contribution from Highland Lakes ac-ft/yr 20,795 19, Percent of Time Critical Criteria Met at Austin (46 cfs) % Percent of Time Critical Criteria Met at Bastrop ( cfs)* % Percent of Time Critical Criteria Met at Columbus ( cfs)* % Percent of Time Target Criteria Met at Wharton % n/a n/a 62 Percent of Time Target Criteria Met at Austin (100 cfs) % Percent of Time Target Criteria Met at Bastrop (240-1,030 cfs)* % Percent of Time Target Criteria Met at Columbus ( cfs)* % Percent of Time Target Criteria Met at Wharton ( cfs)* % BAY & ESTUARY ENVIRONMENTAL INFLOWS (Based on WAM simulations) 66 Maximum Annual Colorado River B&E Inflow ac-ft/yr 9,413,856 9,132, Average Annual Colorado River B&E Inflow ac-ft/yr 1,458,132 1,439, Minimum Annual Colorado River B&E Inflow ac-ft/yr 84,258 87, Average Annual Contribution from Highland Lakes ac-ft/yr 60,733 68, Drought-Averaged Contribution from Highland Lakes ac-ft/yr 18,364 17, % of Time Critical Criteria Met at Mouth (14,300 ac-ft/mon) % % of Time Intermediate Criteria Met at Mouth (21,400 ac-ft/mon) % % of Time Target Criteria Met at Mouth (38, ,200 ac-ft/mon)* % * These criteria vary by month of the year. *@ /

30 9$$" >H$$ *$ : $$+ 3#$4$ $$9 %$3<94$ 9'./)'..0$ $ " $$ $ :$<9 $ *'())))$ $ $ 69 /' $* '())))$,/)) 3 '(()$43(4 $% $% +$,()))) $6 $-.)))$3 6 *4 $,/)) $ $ $'())))$% $$ 3/0;04 $$ *3).4 $,),( $ $ ')'(" $: ')))) '()))$ >: $ :* 3 %$ > : $-'0$.) $'),)$ 3'.()4,())))$ 3,(,04+ 3 Texas Water Code; Section ; Provision of Water to Municipality Outside Colorado River Basin.

31 : * $= /' A >$$,)-) :=,)))))3,/4 $$ *< 7>3,.)4 : * 63,4 :$ >$3/(4 : $ $ $ "#5:$,)-) $ ')) :$ $,) 3/'4.' ; 63/-/;4 ')) 3/-/;4 6$ *3-04:$ ""#3(0-)4 "#>3-,-4 $ : $" : 3-/-(4 "9>$" #3;';4 :$,))9 "78 $ - $ $ $$ : $: $* $ $$

32 "$ $ $ + $$: $$$ $ $ :'.() $ $ $ $ $ $ *: $$ = $$* & $$ $ "#:$ $$ + "$$= >G7 $ "$"78* $ $ "$ $"# 6 "$5 "785 $% $: "#$ $ &$* $$ $$ *,))9 $$ *$ + "#: +%B$ 9>$$ $$ $ * $ $,))9 $ %$$

33 "7+3$"4 5 * 5* $" $ : $* $ $ $ = $H $7 $$$ ' ( + $$ $ $"# $%# $$" :,),),)0) :$ *$ % $$$ + & $ $D9 $ $ 3 $=@4$$ $. # / ' 0 1?: :$ $"#%<+/, $ $$ * $

34 "# $ % &. # $ $" $ $+ $# + 0 $" 0 & # " $ $, 0 %. + 0 * 1 & + Milam Burleson Brazos Grimes San Jacinto Hardin Lee Montgomery Washington Liberty Bastrop Fayette Lakeside Irrigation District Austin Waller Brazos River Brazos River Harris San Jacinto River Chambers Garwood Irrigation District Gonzales De Witt Goliad River Lavaca Refugio Lavaca Pierce Ranch Victoria Guadalupe River Guadalupe River Aransas Calhoun Colorado Colorado River Colorado River Jackson Wharton Matagorda Fort Bend Major Rivers Irrigation Districts Counties Brazoria Gulf Coast Irrigation District Galveston - Miles Irrigation Source Ground Water Surface Water Mixed Ground & Surface Water $$ $ > # $$ "# ')$-,)))$.())) %-))) $ $ (

35 $ %* $ ">"D "<3D"<4,))( $5,)); %,))(D $= $ D9 D"* $$$ &,))( $ $ $ /,=$

36 ) ' * + % &. 2 % , + 0 # ' , + Key Issue Related Concerns Model Enhancements Model Layers Hydraulic Conductivity (K) Values Pumping Recharge Water Quality Surface Water- Groundwater Interaction Land Subsidence Thick model layers prevent adequate representation of 3-D flow to wells and of vertical variation in aquifer properties Inadequate representation of true variability in K at and below the dimensions of a county Total amount of historical pumping is underestimated. Improve the spatial resolution for distributing pumping throughout the county. Shallow recharge system that interacts with surface water is ignored and therefore river baseflow are greatly underestimated. Effects of different density among sea water, brackish groundwater, and freshwater on groundwater flow is not considered Uncertainty with existing Colorado River flow studies. Insufficient model detail to predict flow paths near rivers. Subsidence is not modeled by the Central Gulf Coast GAM. Subsidence properties in Northern Gulf Coast GAM are not correlated to aquifer lithologies. Represent aquifer units with multiple model layers. Used lithology from 700 geophysical logs to identify major changes in aquifer physical and hydraulic properties Augmented the GAM K datasets with K estimates from 3,000 short-term and 200 long-term pumping tests from TCEQ records Develop detailed depositional model allows K values to be estimated from sand and clay percentages to K values across the entire study area Met with numerous agencies including GCDs, TWDB, NRCS, and FSA to develop credible methods for improving upon the GAM pumping estimates Used TCEQ and the GCD databases to define location of the well screens Digitized crop acreage maps to define location of pumpage (see Figure 4-2) Performed analysis on river baseflows to determine that average recharge is greater than 1 in/year, which is double GAMs'regional recharge rates Developed relationship between changes in annual precipitation and in total annual recharge based on analysis of baseflows Detailed 3-D maps of groundwater total dissolved solids (TDS) constructed from the analysis of the geophysical logs Modeling will include simulation of density-differences caused by the high TDS of sea water and brackish groundwaters Performed new flow study on Colorado River from available information that avoids problems with accounting for large river diversions Included a 100 to 200 foot thick upper model layer to help simulate shallow groundwater - surface water interaction Used lithology from 700 geophysical logs to identify major changes in aquifer lithology that directly determine the aquifer's subsidence properties Improved vertical resolution of the model will provide better representation of the vertical variation in the aquifer's subsidence properties Note: NRCS- Natural Resource Conservation Service; FSA - Farm Service Agency, TWDB - Texas Water Development Board %,))(H D $9 3D94 <>3<>4 :@%,))/D9 :IBD"*D9 $? D$3?D43C,))(4"D"*D9 3"$,))(4 $<> $D9 $

37 0 D91$2 D%<3 D4 3D" 47 *"* D9$ $,))- : /D9 $,($$'./''.-( "# + :"*7* (* H $$> $ $ * $ ) ' * + % &2 ' & $+ 1 4 $', ' - " $# 0. % $" $ $+ $# Estimated Maximum Net Drawdown (ft) over a 25-year Period Groundwater Lakeside Irrigation District Gulf Coast Irrigation District Pierce Ranch District Availability Model Chicot Aquifer Evangeline Aquifer Chicot Aquifer Evangeline Aquifer Chicot Aquifer Evangeline Aquifer Northern Gulf Coast Central Gulf Coast / D9 9$ D9$ D9 $$ $ %9 $">D"<" D"<$">"D"< $ >""$ D"< )

38 ><>9 $,'()))$,))))$ '.0)'..; -()))$'())))$ $5 *D"<5 $ $ - :5 : $$ *$ $ *$$* ::D"< $ $ $? $$ $ $ 2 ' 0 1 "$$ D"D%<5$$ $# %<$$"# -)))$ $$$',())) $ $''0))) #C,))- $ $,));$ $,));,)') $ $ $,))($ $$$$5 $$+ $ $$

39 = 9&<%9 $ $ $ #"$3"4 $% 7 374$ $$ $$ <A $,))/3 >,))(4 $,))( &,))( +$ 34 $$3D"D<4 9F,))(<$9&<%9 D%$3D%4$ $$ F,))( + D"%<$F$,))( 9&<%9 +3<4 $ + $ D< #$$ $)))#,))($(-))> 9$,))(#$ () $ = #" 0 #,))(:$A$ $ <$$ $=$ $A /

40 $ & $$ = B$* $ <B $''(;*$ $ &(;),<' +$ $$ /0)))$ ;( ()() //= ) ' * + % & $- % % + ' $ - $ " + $ 3 + $0 67, $+ $# + Parameters Lakeside Gulf Coast Garwood All three districts Total diversions (acre feet) 114, ,000 78, ,000 Total delivered (acre feet) 78,000 89,000 54, ,000 Total system losses: 36,000 55,000 24, ,000 Seepage (acre feet) -6,000-10,000-4,000-20,000 Overflows (acre feet) -5,700-7,200-3,900-16,800 Evaporation (acre feet) -2,000-3,600-1,500-7,100 Evapotranspiration (acre feet) -5,000-6,000-2,400-13,400 Accounted for losses Preliminary (acre-feet) 18,700 26,800 11,800 57,300 Unaccounted for losses such as breaks, leaks, and unauthorized use. 17,300 28,200 12,200 57,700 Potential delivery system savings (acre-feet) 15,425 22,500 10,225 48,150 Notes to table: 1. Values for total diversions and the total water delivered were derived from years 1999 through Losses (seepage, evapotranspiration, evaporation, overflows) were calculated for the modeled canal lengths for Lakeside, Gulf Coast, and Garwood, which are 286, 337, and 124 miles, respectively, 3. Seepage losses shown are based on a soil permeability of 0.06 inches per hour. 4. Season length was taken as 211 days (from April to October).

41 > : $H $ $+ 3"#'..'4 0') <" $$$ B34$ D<I,-($ $I,0) ))$D,; '/,$D"<,,-'$)$ $ > $ $ = $ $J))-3?<3?<4 $"94+ $ $ ))- >#5<93>#'.;04,))))$3 //4 7 = $ $ $$$$*7 $$ $ 3'.04 /9& ;'))$3 //4 " # 7 7 3'4 H3,4$ H 34=):H3/4 7$$ -/,$$ $ $ $$$

42 /.$$ $'-$ D "D '/))$3 //4 $ " &$$34 7 $1$2$,- *$ + 9'/F0<,/' '(%$$ $'($*( $$ '-0))$3 //4$ $$*?,))(*$ "<$ $ >73,))4$ "<$')'( :"<$$$$ $ '( $ " =$ $ $$$$ %$ = "#$= * $*$ $ // $ : $ %& " /(,))$3 /(4 $,)-): :

43 $ /( )(; $' >93>94),. $, >9 ) ' * + % &3 8 # 0 # " 0 ' + - $ ' $ # $" $ $+ $# District On-Farm Water Conservation from BMPs 2060 acres in Production (acre-feet per year) 1st crop 2nd crop 1st crop 2nd crop Total Conservation (acre-feet per year) Lakeside 22,200 20,006 10,629 4,873 15,503 Gulf Coast 17,700 10,651 9,585 2,934 12,519 Garwood 21,000 15,922 10,055 3,879 13,933 Pierce Ranch 4,871 3,746 2, ,245 Total 65,771 50,325 32,601 12,599 45,200 Note: BMPs were applied to 84 percent of acres in production for 1 st and 2 nd crop in the Lakeside, Garwood and Pierce Ranch districts and 95 percent of acres in production for 1 st and 2 nd crop in the Gulf Coast District. 1 st crop BMP conservation savings were estimated at 0.57 acre-feet per acre and 2 nd crop savings were estimated at 0.29 acre-feet per acre. $$$$ $%,))) 3D"D4 ;'-.-3"G>,)))4" '- 9 + "# #%<,))- ' ( &$ $%$ $ " $$ 7$ * $ *< #" < = $ 7 $ $ * $

44 & $ )'), K$ )( #" $7 $ ) " 7$$$ $$ $+$ $+ $ $$ ;($,,))$+ (),(,'()) $');))$$* $$$ 9$ $$$,/ $ ') $ $ : $ /- ) ' * + % &4 8 # 0 $ + - $ ' 0 & $ 5 * $# $ % 2060 savings from New Varieties District Decrease from 2- crop demand Increase from 1-crop demand Total decrease in demand Lakeside 18, ,877 Gulf Coast 9,757 1,447 8,310 Garwood 14,586 1,042 13,544 Pierce Ranch 3, , % adoption 46,102 3,171 42,931 75% adoption 34,577 2,378 32,199 (

45 / ) ' * + % &6 $' $ %, ' ' % $ - $ " + Parameters Lakeside Gulf Coast Garwood Pierce Ranch Total Total diversions (acre-feet) 114, ,000 78,000 On-farm 336,000 Total delivered (acre-feet) 78,000 89,000 54,000 Only 221,000 Total system losses: 36,000 55,000 24, ,000 Seepage (acre-feet) -6,000-10,000-4,000-20,000 Overflows (acre-feet) -5,700-7,200-3,900-16,800 Evaporation (acre-feet) -2,000-3,600-1,500-7,100 Evapotranspiration (acrefeet) -5,000-6,000-2,400-13,400 Accounted for losses Preliminary (acre-feet) 18,700 26,800 11,800 57,300 Unaccounted for losses such as breaks, leaks, and unauthorized use. 17,300 28,200 12,200 57,700 Potential delivery system savings (acre feet) 15,425 22,500 10,225 N/A 48,150 On-Farm (BMPs) 15,503 12,519 13,933 3,245 45,200 Rice Varieties (75% adoption) 13,408 6,233 10,158 2,401 32,199 Total Estimated Savings (Preliminary) 44,336 41,252 34,316 5, ,548 - $$ $A $$ <$ $ % $$ %$$ 979>$

46 5.0 Facility Siting (Engineering) Working in tandem with the river water availability study, stakeholders and advisory groups, the facility siting study explores possible locations, configuration and sizing of Project components such as diversion points, off-channel storage, pipelines, and other important Project elements. The results of this study will also help guide SAWS selection of potential transmission pipeline routes to the San Antonio area. The 2005 work effort was designed to assess potential site characteristics needed for the major facilities as well as conditions that would limit the ability to construct the Project components. The process includes compiling readily available information such as threatened and endangered species habitat, wetlands, and existing utilities, as well as potential areas where construction of Project elements would be compatible with existing land uses based on technical criteria. Once the technical information is compiled, costs can be estimated and then possible economic, environmental, and social impacts can be assessed through public involvement processes. Study Status A database search was performed to gather environmental, cultural and archeological, existing infrastructure and utilities, Federal Emergency Management Agency (FEMA) floodplains, and land use constraints within Colorado, Wharton, and Matagorda counties. The data search was limited to publicly available information including the following resources: Satellite Imagery/Aerial Photography Geology/Soils Topography Vegetation Community Types Threatened & Endangered Species (Known Occurrences) Recorded Cultural Resources Sites National Wetland Inventory Floodplains Land Use/Land Cover (from Texas Parks and Wildlife Department [TPWD]) Prime Farmland Oil and Gas Wells and Pipelines (from Texas Railroad Commission) Mines and Quarries Hazardous material sites/landfills Government-owned Parks and Wildlife Management Areas Available Electrical Transmission Facilities In general, the preliminary data has been obtained for the study area: Colorado, Wharton and Matagorda counties. This high level examination of existing infrastructure and utilities, and environmental and cultural resources will help identify possible impediments to locating potential off-channel storage facilities (OCSF) and associated intake structures, pumping stations, and pipelines. Figure 5-1 shows one example of data collected related to oil and gas wells and pipelines. The basic approach to siting a facility is designed to avoid constraints and minimize potential impacts. 08_FINAL2005PVA SEC5_SW.DOC LSW

47 FIGURE 5-1 Potential Impediments to Siting in Project Area, Example of Mapped Oil and Gas Pipelines Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project An evaluation matrix will be used to help evaluate and screen potential sites identified. The matrix will consider four main areas: land use, environmental considerations, technical elements (i.e., soil type, elevation), and costs. Findings Maps of existing features (natural and manmade) have been developed as identified from literature searches, aerial photography, helicopter surveys, and field surveys from publicly accessible property in Colorado, Wharton, and Matagorda counties. The information will help efficiently evaluate potential sites for facilities. The largest facilities related to the Project are the OCSF s, which could range from 1,000 acres to 8,000 acres in surface area. Intake facilities include river intake(s), river pumping station(s), pipelines, and ancillary facilities from the Colorado River to the OCSF sites. Transmission facilities include conveyance pumping stations, pipelines, terminal storage tank, and ancillary facilities from the OCSF to the delivery point (i.e., extent of LCRA statutory district). 08_FINAL2005PVA SEC5_SW.DOC 5-2

48 FIGURE 5-2 Sample Diagram of Off-Channel Storage Facility Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project In addition to mapping the study area to identify potential sites for various Project components, the facilities siting effort during 2005 focused on conceptual sizing of various elements. Based on modeling by the Surface Water Availability Team, flows available for diversion during the period of record were determined. Similarly, delivery rates to the San Antonio area were determined based on a constant flow rate (i.e. 215 cfs) needed to deliver 150,000 acre-feet per year over a period of 50 weeks, which assumes a 2 week period of down time for annual maintenance). Considering Colorado River diversions, evaporative and seepage losses and delivery rate, calculations of storage capacity necessary to develop a firm yield were performed. These calculations determine necessary sizes for diversion facilities, off-channel storage and other components of the Project. At this conceptual design phase, facilities have been sized for the purpose of identifying potentially suitable locations and as a basis for cost estimates. Risks There are potential risks and benefits associated with facility siting aspects of the Project. As the studies progress, more detailed daily river modeling information may allow more efficient design of facilities, potentially reducing costs. On the other hand, design issues (i.e., sub-surface soil conditions) may be identified that increase costs. 08_FINAL2005PVA SEC5_SW.DOC 5-3

49 The future field assessment of potential sites may identify environmental, cultural, or other constraints not currently identified at this high level of analysis. Fortunately, the alternative sites are numerous, which will help manage this risk. As with any infrastructure project involving land acquisition, sites preferred for technical, environmental or cost reasons may or may not be owned by one or more willing sellers. 08_FINAL2005PVA SEC5_SW.DOC 5-4

50 6.0 Environmental Issues If constructed, the LSWP creates a potential to change the timing and volume of flow in the Colorado River and delivery of freshwater inflow into Matagorda Bay. Several LSWP studies are currently underway to evaluate the potential environmental effects of the Project. A summary of the status of these studies and their implication for the viability of the Project is provided in this section. 6.1 River Water Quality The goal of the Water Quality study during 2005 is to collect data from various segments of the lower Colorado River and refine models to estimate potential changes in water quality that could result from the LSWP. Once completed, the model and results will be used by biologists studying river aquatic habitat and the Matagorda Bay and estuary system to predict potential effects on the flora and fauna of those systems. Results of the studies will also affect the design and operation of the water treatment facilities and processes to ensure drinking water standards are met. Study Status To enhance understanding of existing river water quality conditions, the Water Quality Team performed an intensive low-flow water quality survey of the lower Colorado River in November This study included round-the-clock sampling at 38 stations, including 11 wastewater treatment plants, 8 tributaries, and 19 stations on the main stem of the river. The study was performed when the flow at Bastrop was approximately 600 cubic feet per second (cfs). The QUAL-TX model is used by TCEQ to evaluate likely effects on water quality of wastewater discharges, river diversions, and other activities requiring permits from the state. This field study was the first comprehensive survey of the river from Austin to Matagorda Bay suitable for calibration of the QUAL-TX model to study potential changes to water quality related to the LSWP. Since the completion of the November 2004 low-flow survey, the Water Quality Team has extended the existing TCEQ QUAL-TX model from its traditional end point at Smithville to Bay City, entering updated hydraulic coefficients based on a series of dye studies, and calibrating the model to the 2004 low-flow survey data, as well as other datasets. This model is herein referred to as the LSWP QUAL-TX model. To increase the certainty of current model predictions, a low-flow validation study slated for implementation in 2005 has also been designed. This study, which is similar to the low-flow calibration survey performed in November 2004, will be used to further refine the LSWP QUAL-TX coefficients. The model is currently being modified to allow for future simulations, preliminary results of which will be available in late 2005, with final results available in Figure 6-1 shows some of the upper model segments. 09_FINAL2005PVA SEC6_SW.DOC LSW

51 FIGURE 6-1 Upper Model Segments on the Colorado River Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Based on an October 2004 recommendation of the Science Review Panel (SRP), the Water Quality Team also designed a monitoring study (the Diel DO Study ) to evaluate daily fluctuations in dissolved oxygen (DO) in the lower Colorado River. Dissolved oxygen levels fluctuate naturally during a 24-hour period due to plants generating oxygen during the daylight hours. For this reason, minimum dissolved oxygen conditions frequently occur just after dawn. The Diel DO Study was conducted in late July and early August, 2005 to evaluate the current ranges in these daily fluctuations during high temperature conditions. This information will be used to evaluate if these daily DO swings may be a concern under future project conditions. The other major water quality-related effort was the development of the initial model (using a program called BATHTUB developed and maintained by the U.S. Army Corps of Engineers) that will be used to predict water quality in the off-channel storage facilities. Once potential sites for the off-channel storage are selected and diversion rates are determined, this model will be applied. Findings Based on the existing data and calibration, no water quality concerns were identified in the river below Smithville. Because the section of the river between Austin and Smithville has the highest levels of wastewater discharges, it is the reach most likely to experience potential changes in water quality if the river flow regime changes. 09_FINAL2005PVA SEC6_SW.DOC 6-2

52 For the 2004 PVA, a water quality analysis was performed (Chapter 5) using the TCEQ QUAL-TX model available at that time, with specific modifications to approximate summertime conditions. Since the finalization of the 2004 PVA, TCEQ has modified several characteristics of the input files to their QUAL-TX model of the lower Colorado River. This new QUAL-TX model, coupled with the changes implemented for the 2004 PVA, generates a similar overall result to the model version used in the 2004 PVA. Therefore, the recent changes to the TCEQ QUAL-TX model do not appear to change the results of Chapter 5 of the 2004 PVA. Because the preliminary results are limited by the model and the input parameters used in the evaluation, refinements to the QUAL-TX model and additional low flow water quality testing were included as part of the 2005 work program. In late 2005, the recent changes made to the TCEQ QUAL-TX model will be reviewed and incorporated into the LSWP QUAL-TX model. Combined with the updated coefficients from the calibration and validation low-flow surveys, the final LSWP QUAL-TX model will give the clearest picture, to date, of potential future water quality in the river. QUAL-TX provides a single estimate of dissolved oxygen at each point in the model grid for the flow, temperature, and discharge conditions of the specific model run. Once the model is updated and validated in fall 2005, the likelihood that some combination of conditions would result in a certain DO level will be characterized in the LSWP QUAL-TX model through simulation algorithms, called an uncertainty analysis. The simulations, commonly used in modeling, run the model many times, changing the inputs and conditions for the model in a way that matches the likelihood of each input or condition occurring. The result allows estimates of the probability that a specific model result will occur over time. While not required at this time as part of the regulatory process, this analysis will provide estimates of risks and the probability of their occurrence that may be helpful in designing key facilities for the Project, developing operational guidelines, and evaluating the potential effects in the Matagorda Bay Health Evaluation. Risks The water quality studies associated with the LSWP are intended to increase the understanding of the existing conditions in the lower Colorado River, predict possible changes to those conditions, and assess the likely result that those changes could have on water quality. Potential risks (and benefits) related to water quality include: Because operation of the LSWP may result in lower Highland Lake releases to meet downstream irrigation needs during the summer months, low-flow conditions could exist when temperatures are higher. While this is a more natural condition in rivers without upstream reservoirs, it could result in decreased levels of dissolved oxygen in the river and potentially increased levels of nutrients resulting from treated wastewater discharges during low-flow conditions. Changes in regulations or wastewater discharge permit limits could also affect water quality. Better water clarity resulting from lower flows during the spring spawning season could benefit reproduction of aquatic species such as the blue sucker. 09_FINAL2005PVA SEC6_SW.DOC 6-3

53 6.2 River Habitat Study Status The LSWP has the potential to alter the flow regime for the lower Colorado River. As with any change of this type on a controlled (dammed) river system, the ecosystem can be affected both positively and negatively. The study team is therefore developing ecologically based tools, or models, using data from existing studies and additional information gathered in the field. The models developed will help predict the effects of a range of flows on the ecology of the lower Colorado River system. For example, does a flow of x cfs create more or less riffle habitat, and what organisms depend on that type of habitat? Would this change benefit some organisms and be detrimental to others? In addition, is that habitat more important to the organism in a certain season (because of spawning or another reason)? In January 2005, the study team finished selecting ten intensive study sites on the river to help develop these models (Figure 6-2). The sites were selected following aerial and field reconnaissance to effectively and efficiently reflect the representative habitats and regions of the river. The resulting maps were used to calculate the relative proportion of each habitat type for each of the five river segments. Webberville Segment: (River Mile (RM) 290 to RM 258) Austin to Utley Bastrop Segment: (RM 258 to RM 237) Utley to Bastrop Smithville Segment: (RM 237 to RM 137) Bastrop to the confluence of Cummins Creek in Columbus Eagle Lake Segment: (RM 137 to RM 100) downstream of Columbus to Garwood Egypt Segment: (RM100 to RM 34) downstream of Garwood to Bay City The study team used the representative reach approach to select the ten intensive study sites. The rationale behind this approach is that in general, the mesohabitat types within each segment tend to occur in a repetitive pattern and each major mesohabitat type found per segment is represented at least once in a relatively long reach of stream. The general rule of thumb for a representative reach is approximately 10 to 30 channel widths for the length of the reach. For the lower Colorado River that would result in reaches for intensive sites of approximately 0.5 to 1.0 mile in length. The study team then identified multiple representative reaches within each river segment. Criteria used to evaluate these reaches included: Types of instream (e.g. backwater, boulders, islands, riffles, runs, sand-gravel bars, etc.) and riparian mesohabitats found within each representative reach and how similar it was to the characteristics of the overall segment; Areas where water quality may be of greatest concern during low and/or high flows; Special aquatic habitat features important to key species (such as the blue sucker); Distance to boat ramp (for ease of access); In February 2005, the study team performed an initial reconnaissance to identify river shape and structure (called geomorphology) and habitat in greater detail at the selected ten locations (see example, Figure 6-3). 09_FINAL2005PVA SEC6_SW.DOC 6-4

54 FIGURE 6-2 Map of 10 Intensive Study Sites Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Beginning in spring 2005, the Project team surveyed all ten Intensive Study Sites collecting detailed bathymetric data (measurement of the depth of water), water surface elevations, flow rates, and edge of water coordinates (to indicate the range of flows). This information needs to be collected during three distinct flow conditions (low, moderate, high) to develop, calibrate, and validate the model. Most moderate flow data and some low and high flow data have been collected as of spring Given appropriate flow conditions, the remainder of the high flow data should be collected late summer 2005 (during releases from the Highland Lakes to meet irrigation demands) and the remainder of low flow data collected in fall Biological validation data, including fish surveys at a range of river depths and velocities, are also being collected at each flow range. 09_FINAL2005PVA SEC6_SW.DOC 6-5

55 The study team also began a series of studies specific to a resident fish, the blue sucker, of the lower Colorado River (Figure 6-4). FIGURE 6-3 Example of Habitat Mapping at 10 Intensive Study Sites Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project 09_FINAL2005PVA SEC6_SW.DOC 6-6

56 FIGURE 6-4 Cycleptus elongatus - Blue Sucker Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project The blue sucker is not listed as an endangered species (neither federally nor by the state), indicating that the species is not at immediate risk. However, it is found on a state list of threatened species (or species meriting special observation), so it is a focus for study as part of the Project. Because little is known about the life-cycle of the species, the study was designed to help understand the habitat needs for the blue sucker and to help design facilities in ways that protect the species. In the fall of 2004, 30 adult blue suckers were collected and implanted with radio tags for scientific purposes (Figure 6-5). 09_FINAL2005PVA SEC6_SW.DOC 6-7

57 FIGURE 6-5 Columbus Riffle Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project The tags allow the fish to be tracked as they move upstream and downstream in the lower Colorado River. The information obtained provides the study team with data on migration (triggers, distances, and timing), habitat preferences, and spawning locations. During the spring, over 70 percent of the movement was upstream with fish swimming over 170 river miles to reach suitable spawning locations. At the conclusion of spawning activities, the study team focused on the collection of larval and juvenile blue suckers to identify preferred habitat locations for these early life-stages. To date, no larval or juvenile blue suckers have been located, but sampling during low flows will likely increase the effectiveness of sampling techniques and increase the probability of locating habitats for these early life stages. As the study progresses, additional migration, spawning, and detailed habitat information will be collected and ultimately input into the environmental flow/habitat model to assess potential impacts and/or benefits to this species and the aquatic community in the lower Colorado River. The study findings will also be used in developing site plans and operating procedures that consider the needs of this important species. Preliminary Results The initial year of studies have provided substantial preliminary information, including the documentation of the following: The study team has visited the ten intensive survey sites several times to document river shape and structure (geomorphology), evaluate habitat, and sample aquatic species present. 09_FINAL2005PVA SEC6_SW.DOC 6-8

58 The study team has begun developing models to relate river flow to quantity and quality of aquatic habitat. The 30 blue suckers (species of interest in the Colorado River basin) that were tagged with radio transmitters in 2004 have been tracked. Upstream movement of some individuals over 170 river miles was observed in the spring. The team observed and videotaped spawning of approximately 40 to 50 blue suckers below Longhorn Dam in Austin during March event, when flows and water depth were appropriate for spawning. Larval and juvenile blue suckers have been difficult to locate and collect (through June 2005), as reported in other river basins, so work will continue to better understand this phase of their life cycle. Specific habitat preferences for adults (boulder/bedrock/structure habitats) have been identified, which will be important for assessing potential impacts from facilities or changes to the flow regime on specific sites. Risks The assessment of the effect of the Project on the riverine environment centers on how potential changes may influence the flow regime and water quality for the lower Colorado River. Flow regime changes on the lower Colorado River have the potential to affect aquatic habitat, fish migration, and recreation in potentially both beneficial and detrimental ways. There are potential risks and benefits associated with the flow relationships to habitat aspect of the Project. It is possible that alterations to the flow regime will be beneficial for some physical, chemical, and biological components of the river. It is also likely that the alterations will be less beneficial or detrimental for other species and habitats in the river. Changes in flow depth, velocity, and timing could either reduce or increase the available habitat for different species, including the blue sucker. In addition, changes may affect the life stages of each species differently. Improved water clarity, as a result of decreased river flow, during the spring spawning season could be beneficial for spawning of a number of species. LSWP facilities and structures could impede adult blue sucker migration on the river. Alternately, the results of the study will provide information that helps design facilities that protect fish passage. The timing of changes in habitat availability will strongly influence the assessment of risks/benefits (i.e., adult and juvenile habitat should be available year round, discharge dependent migration corridors in November to March, spawning habitat in late February to early April, and larval rearing habitat in mid-march through April). Potential risks include streambed aggradation, decreased channel maintenance/sediment flushing capabilities, increased sediment deposition in key habitats (i.e., spawning cobbles and/or larval rearing or nursery habitat), or increased bank erosion. These risks, if realized, would decrease several desirable types of habitat. The study and models developed will help identify whether flow regime changes are detrimental or beneficial at a specific time and location. 09_FINAL2005PVA SEC6_SW.DOC 6-9

59 Potential benefits include modified sediment transport pattern to create beneficial habitat for fish or other components of the biological community (sand or gravel/cobble bar development, etc.), improved flushing of silt and sand material from gravel habitats, reduced sediment deposition, or reduced bank erosion. These benefits, if realized, would increase or protect several desirable types of habitat. The study and models developed will help identify whether flow regime changes are detrimental or beneficial at a specific time and location. Potential risks include reduction in recreational fishing via watercraft (motorized boats, kayaks or canoes) during summer low-flow conditions; however, such conditions could be beneficial for wade-fishing and swimming. It should be noted, however, that the recreational use of the lower Colorado River is limited compared with the upper river and Highland Lake system and the neighboring Guadalupe River. Furthermore, recreational impacts are expected only with a dramatic reduction in flow conditions which is not expected to happen as a result of the implementation of the LSWP. 6.3 Bay Health The Matagorda Bay Heath Evaluation is studying bay health from several different perspectives to help understand current conditions in the bay, and to predict the potential effects, of the Project on the Matagorda Bay system shown in Figure 6.6. Study Status Several key areas of the study have progressed this year, and considerably more progress is projected by year s end. Collected and compiled extensive key data sources Developed and documented the Framework for Assessing Bay Health describing the approach for measuring the health and productivity of the Matagorda Bay system Started development of a salinity and hydrodynamic model of the bay, including some focused bathymetric mapping of key areas Started mapping of habitat and marsh areas of the bay, including field studies to ground truth available information Began to summarize, analyze and plot biological and chemical data on the bay Initiated additional statistical analysis of the TPWD Coastal Fisheries data Conducted an analysis of nutrient loading into the bay system Began the development of relationships between habitat and key species found in Matagorda Bay. 09_FINAL2005PVA SEC6_SW.DOC 6-10

60 FIGURE 6-6 Matagorda Bay System Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Bay Health Framework and the State Methodology One of the legislative requirements of the LSWP is that freshwater inflows after the project is implemented are adequate to maintain the health and productivity of Matagorda Bay. A Framework for Assessing Bay Health (Framework) has been developed as part of the feasibility analysis for the LSWP to guide the studies that will provide answers to how bay health will be maintained after the Project. The Framework approaches bay health by focusing on three components: inflows, and how they will be altered by LSWP; habitat, including salinity, vegetation, substrate, and other components; and biology, which will attempt to link changes in inflow and habitat to biological changes. This approach focuses on the different functions of various parts of the bay (open bay, secondary bays, marshlands, deltas) to better determine how they might be impacted by varying inflows. The State Methodology is a method for determining optimal inflow requirements to the bay system developed by the state resource agencies. How do the existing State Methodology and models relate to the framework? A substantial amount of resources has been expended over the past ten years in applying the state methodology to Matagorda Bay. Numerous insights about the bay have been developed because of those efforts. The State Methodology and the Framework are dealing with the same issue, namely bay health and productivity; however, there is not a tremendous amount of overlap between the two approaches because they are designed to answer fundamentally different questions. The Framework directs a set of studies that will determine the health and productivity of Matagorda Bay today, as well as projecting what the health of the bay will be in the future, both with and without LSWP. 09_FINAL2005PVA SEC6_SW.DOC 6-11

61 In contrast, the State Methodology was designed to determine the freshwater inflow patterns needed to optimize the productivity of the entire bay complex. This optimization model was not developed to, and indeed cannot, answer the questions posed about the future health of the bay. Because models are typically only able to answer the questions they were specifically developed to answer the State Methodology may not be well-suited to answer the questions that the legislative mandate requires be addressed. The impact of the LSWP will most likely be a result of reduced freshwater inflows during higher inflow conditions, and/or changes in the timing of inflows. The State Methodology cannot be readily adapted to assess the potential impacts on bay productivity resulting from such changed conditions. Preliminary Results Bay Health Framework The full Framework document can be found at A summary of the Framework follows. The principal charge for the Matagorda Bay Health Evaluation component of the Project is to assess the environmental effects that could result from changes in inflow patterns to the Matagorda Bay system. The study is to respond directly to the requirement in Section (n)(3) of the Texas Water Code, which codifies the LCRA Act, to ensure that beneficial inflows remaining after any water diversions will be adequate to maintain the ecological health and productivity of the Matagorda Bay system. The LCRA Act further charges that the analyses use the best science available. The Framework is centered on an understanding of three primary elements: namely, Inflow and modifications thereof, Habitat, and Biology. Said another way, the route to understanding and quantifying potential environmental effects on the bay system starts with a driver Inflow, which could be affected by the Project; continues with an understanding of the effect that inflow changes could have on bay physical, chemical and biological/vegetative makeup (Habitat); and concludes with the potential changes in the Biology of the bay system. This multi-faceted approach characterizes inter-related elements of the health of the bay, which collectively provide a basis for measuring overall bay health (Figure 6-7). It is important to note, that while the initial emphasis will be placed on the analysis of the effects that changes in inflow may have on bay health, inflow is certainly not the sole driver of conditions in the bay. Many other factors, some controllable and others not, are potential drivers of bay health, and will be accounted for insofar as possible in the evaluation. The major components of the proposed approach are summarized below. Habitat provides a powerful framework for viewing the health of the ecosystem. Water chemistry, including salinity, is an important component of habitat, along with many other factors. Salinity is driven largely by changes in freshwater inflow, and will be investigated using a hydrodynamic/salinity model. The Framework also provides for improved understanding of direct relationships between inflow and species productivity and benthic diversity. 09_FINAL2005PVA SEC6_SW.DOC 6-12

62 FIGURE 6-7 Schematic of Bay Health Evaluation Framework Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Inflow An initial analysis is underway of preliminary future monthly bay inflows, developed as part of the river modeling component of the Project (see Section 4.1 of this document). This preliminary information will change as part of the ongoing modeling and refinement of the Project design during the Study Period. Nevertheless, this preliminary information was useful in providing insight into existing inflow conditions, potential future inflow conditions, and a possible inflow scenario associated with the Project in the future. This information and subsequent refinements will be used as inputs to the bay study, and in return, the bay study will provide guidance based on its findings to help guide the conceptual design of the Project and the overall operation of the LCRA system. A couple of examples from this analysis are shown in the following two figures. Preliminary estimates of Colorado River inflows to Matagorda Bay are shown for the winter month January (Figure 6-8) and the late summer month September (Figure 6-9). The preliminary estimates were summarized for future conditions with and without the project and over a long simulation period based on the rainfall and streamflow conditions from 1940 to The January graph shows little change (a slight decrease in flow) with and without the project as water is diverted and stored during the winter, while the September graph shows some increase in inflow with the Project, due principally to reduced irrigation demand and altered operation of the overall system. 09_FINAL2005PVA SEC6_SW.DOC 6-13

63 FIGURE 6-8 Preliminary Future January Monthly Bay Inflows Without and With Project Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project FIGURE 6-9 Preliminary Future September Monthly Bay Inflows Without and With Project Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project 09_FINAL2005PVA SEC6_SW.DOC 6-14

64 It is important to note that the Colorado River is not the only source of freshwater inflow to the bay. Numerous coastal basin drainages flow into the bay. In addition, a significant portion of the Gulf Coast Irrigation District, where river water is delivered to irrigate rice, eventually drains to the coastal marshes of East Matagorda Bay. The location of these drainages may feed more habitats of greater ecologic value than the main river channel. In addition, the timing of irrigation releases has the potential to provide water to these areas during even severe droughts, when many organisms retreat to these areas as a refuge. More information on the timing and volume of these releases, and their potential impact on bay health, will be developed as the study progresses. This information will be developed through close cooperation with the River Water Availability study team and Agricultural Conservation study team. Habitat The habitat in the bay (e.g., open bay, brackish marsh, sea grasses, freshwater marsh) provides the home for the organisms that live there, providing shelter, food sources, hiding places, nurseries, and so forth. The Bay Study will map the physical, chemical, and biological characteristics of key portions of the Matagorda Bay System. This information will later be linked to the preferences of different species and life stages and, to the extent practicable, modeled to allow projection of how habitat might be affected by changes in the volume, timing, and location of freshwater inflow. FIGURE 6-10 Matagorda Bay System Marsh Classifications Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project 09_FINAL2005PVA SEC6_SW.DOC 6-15

65 FIGURE 6-11 Oyster Reef and Seagrass Distribution Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Marsh and sea grasses are important habitat for fish and wildlife. The study team will be refining and adding detail to the mapping of this habitat component, particularly along the northern shore of Matagorda Bay east and west of the Colorado River in the areas potentially affected by changes in inflow attributable to the LSWP (Figure 6-11). These early results, coupled with observations by the Project team during field studies conducted during 2005, indicate that seagrasses are somewhat more abundant in Matagorda Bay than had been previously reported. The team will next focus on evaluation of changes that are occurring in marsh distribution and characteristics over time. There does not appear to be significant overall increase or decrease in wetland habitat within Matagorda Bay, although some erosion is occurring on wetland margins along the Gulf Intracoastal Waterway (GIWW), and the deltaic development at the Diversion Channel mouth continues. The aerial extents of the developing marshes were digitized from an historical sequence of aerial images: 1995, 1999, 2001, and A 1989 photo was used to document pre-diversion channel conditions. The historical sequence of photos and corresponding maps of the marsh coverage revealed the pattern of deltaic marsh development since the dredging of the diversion channel. Results show that after an initial phase of dramatic marsh growth which colonized all of the suitable dredge spoil areas, marsh growth has now dramatically slowed. 09_FINAL2005PVA SEC6_SW.DOC 6-16

66 Biology The organisms that live in and depend on the bay are a key focus of the study. To date, an extensive database of data on the bay, including biological data, has been gathered, organized, and placed in a form for use by the study team in its evaluations. Initial summaries of some of the key data sets, including the TPWD Coastal Fisheries data, have been prepared to guide the upcoming statistical modeling efforts. Spatial summaries of the data have been prepared similar to the example in Figures 6-12 and 6-13, below. These examples illustrate when and where brown shrimp were in the bay (present in late spring and summer 1995, but not in winter or early spring), and if so, where. Development of statistical relationships and models for bay biology is ongoing, with results available in 2006 to support the bay health evaluation. FIGURE 6-12 Abundance of Brown Shrimp in TPWD Data, March 1995 Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project 09_FINAL2005PVA SEC6_SW.DOC 6-17

67 FIGURE 6-13 Abundance of Brown Shrimp in TPWD Data, May 1995 Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Risks and Benefits Potential risks and benefits associated with the Matagorda Bay aspects of the LSWP include: The bay system is complex, and the studies and analyses that support this evaluation are similarly complex. Because the bay framework looks at the bay from a number of different perspectives, it is likely that the results will not provide simple guidance for decision-makers and regulatory agencies. The results will likely show that some organisms and habitats favor certain conditions, while others favor different conditions. This will place an additional burden on regulatory agencies as they make decisions regarding the permits associated with the project. A component of the flow into the Matagorda Bay system comes from coastal drainage basins that include irrigation districts. The savings achieved through agricultural conservation have the potential to decrease irrigation return flows to these drainage basins which generally flow into the marsh areas on the northern boundary of the bay system. However these irrigation return flows may also decrease without implementation of this Project because of the limited availability of water for irrigation. These return flows, and their potential effects on the bay, will be evaluated as part of the study. The potential for delivery of water to these marsh areas by using the irrigation water delivery system provides an opportunity for enhancing productivity by timely delivery of freshwater to the marsh complex. 09_FINAL2005PVA SEC6_SW.DOC 6-18

68 The models and relationships developed as part of the study might not reflect future conditions and responses in the bay as accurately as desired. The development of a long-term monitoring plan as envisioned as part of the Project will help alleviate this risk. 09_FINAL2005PVA SEC6_SW.DOC 6-19

69 7.0 Permitting Requirements During the development of the Study Period Plan, key local, state, and federal permits required for implementation of the Project were identified. The Project is taking a proactive approach to permitting, proceeding concurrently with both the feasibility studies and the permitting processes. The major permits for the Project include: Water rights permits or amendments, including the interbasin transfer authorization, under the jurisdiction of the Texas Commission on Environmental Quality (TCEQ) Section 404/10 permit under the Clean Water Act, under the jurisdiction of United States Army Corps of Engineers (USACE) Requires compliance with the National Environmental Policy Act (NEPA) Requires issuance of a Section 401 water quality certification by TCEQ Permits for construction and operation of groundwater wells, under the jurisdiction of Groundwater Conservation Districts Additional permits that are more routine may be needed during the Implementation Phase when construction and operation are underway. Status During 2005, the permitting efforts focused on pre-application coordination with the key local, state, and federal agencies described above. Each of the technical studies were reviewed and refined to ensure that permitting requirements are met by the individual study teams. Pre-application coordination continues with Groundwater Conservation Districts in the study area, TCEQ, Texas Parks and Wildlife Department (TPWD), U.S. Fish and Wildlife Service (USFWS), Environmental Protection Agency (EPA), and the Galveston and Fort Worth Districts of USACE. Socio-economic assessments are required for both state and federal permitting processes as well as to satisfy legislative requirements that the water transfer will protect and benefit users within the lower Colorado River watershed and the LCRA service area. Significant preparatory economic work has occurred during The geographic scope and economic sectors to be analyzed have been identified. Data sets that provide basic information for the economic models have been acquired and/or requested. The next steps include determining which economic forecast models will be used to assess the potential benefits, costs, and direct and indirect effects of the LSWP over time. The economic models for the LSWP will be selected later in As discussed throughout this assessment, key elements of the Project are being developed in Two of the most important elements associated with permitting will be developed in early 2006: 1) the detailed statement of purpose and need, and 2) the project alternatives. These two elements, and the analyses thereof, will serve as the bases for the federal and state permit applications. The development of the alternatives, and their subsequent analysis, will to a large degree be driven by the relationships between and among the studies. For example, the results of the Water Quality and Aquatic Health studies may provide indications of preferred flow regimes. This data, in turn, would affect river water availability modeling constraints and therefore the size of off-channel storage capacity necessary to attain project 10_FINAL2005PVA SEC7_SW.DOC LSW

70 yield. The sizing and location of facilities affects not only the capital and operational costs of the Project, but also the potential for terrestrial impacts. Both the operational and structural components and alternatives for the Project will become the basis for the major permit applications and impact analyses. Findings/Results In March 2005, an overview of the LSWP was submitted to the USACE Galveston District to obtain pre-application guidance regarding the Section 404/10 permit. In a July response to this submittal, the Galveston District indicated their role as the lead district for the Project. The District also indicated that a draft permit application would be necessary to determine whether an Environmental Assessment or Environmental Impact Statement would be required. The Project Team is continuing an active dialogue with USACE including regular follow-up meetings with the District to continue to coordinate submittal of the application and NEPA compliance. Risks There are potential risks associated with the permitting the Project. These include: Water rights permits from TCEQ, including amendments to authorize interbasin transfer, could be affected or their issuance delayed by a number of factors. These factors include ongoing litigation on water rights in the basin or on other statewide water resource issues, other pending water rights application processes, potential protests to the LCRA submittals, environmental flow issues, return flows and others. It is possible that some of these unresolved statewide issues (e.g. environmental flows and return flows) may be addressed through legislative action that could ultimately affect either positively or negatively the permitting of the Project. Although indications are that the federal Section 404/10 permits can be obtained, federal permitting could be affected by timing and delays in the USACE decision regarding the level of environmental documentation they will require for the Project. Statutory changes or changes in Groundwater Conservation District (GCD) rules could affect permitting. The Project Team is working closely with the GCD s to provide information as it becomes available and updated groundwater models for possible use in preparation and issuance of operating and production permits. 10_FINAL2005PVA SEC7_SW.DOC 2

71 8.0 Study Period Costs FIGURE 8-1 Overview of Study Period Costs Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project Total Cost = $41.6 mil Engineering $7.8 mil (22%) Adaptive Management $2.5 mil (6%) Environmental $13.9 mil (32%) Permitting $6.2 mil (15%) Yield $11.2 mil (25%) Figure 8-1 summarizes by major category the estimated funding necessary for the Study Period of the LSWP if the program is implemented as planned. The budget estimate assumes that permits will be obtained on or before the scheduled target date of March 1, 2010, and annual funding commensurate with meeting this schedule will be provided by SAWS. The budget also reserves about $2.5 million in funds specifically to pay for the potential unknowns that arise on any project of this magnitude (Adaptive Management), including the possible preparation of an Environmental Impact Statement. The original estimate for the cost of the Study Period was reduced by $1.4 million in 2004, to a revised total of $41.6 million. At this time, Program Management for the Project is confident that the studies and initial permit processes can be completed on time and within the estimated Study Period budget, assuming those funds are made available (Table 8-1). The study expenditures to date have tracked projections, and projected study period costs have not changed since the 2004 PVA. The United States Fish and Wildlife Service authorized, and Congress has approved, $400,000 to support the Project s Aquatic Habitat Study in The funding, once received, will be applied directly to that study. 11_FINAL2005PVA SEC8_SW.DOC LSW

72 TABLE 8-1 Projected Study Period Costs Lower Colorado River Authority-San Antonio Water System (LCRA-SAWS) Water Project 11_FINAL2005PVA SEC8_SW.DOC 8-2