ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

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Vernalis Adaptive Management Plan VAMP, officially initiated in 2000 as part of the SWRCB Decision 1641 (as revised),is a large-scale, long-term (12-year), experimental/management program designed to protect juvenile Chinook salmon migrating from the San Joaquin River through the Sacramento-San Joaquin Delta. VAMP is also a scientifically recognized experiment to determine how salmon survival rates change in response to alterations in San Joaquin River flows and SWP/CVP exports with the installation of the Head of Old River Barrier(HORB). VAMP employs an adaptive management strategy to use current knowledge of hydrology and environmental conditions to protect Chinook salmon smolts,while gathering information to allow more efficient protection in the future. 4.13.2 ENVIRONMENTAL IMPACTS ANALYSIS METHODOLOGY Approach Overview The proposed project could change water quality in the San Joaquin River, in the vicinity of the discharge(i.e., near-field),and at downstream Delta locations (fully mixed far-field). The project would have negligible, if any, effects on water quality in water bodies (other than the San Joaquin River)upstream of Manteca. Moreover,the project would not cause, either directly or indirectly,hydrologic changes of a magnitude and frequency that could adversely affect aquatic resources, either upstream or downstream of the point of effluent discharge(see Section 4.9, "Hydrology and Water Quality"of this EIR for further discussions regarding hydrologic effects of the proposed project). The statewide SWP/CVP system could undergo hydrologic and operational changes in the future that would have seasonal effects on San Joaquin River flows. These changes would be caused by increased diversion demands (resulting from population growth within the region)and increased water releases (resulting from water quality management and/or environmental restoration initiatives), and associated changes in SWP/CVP operations. The potential impacts of future hydrologic and SWP/CVP operational changes on fisheries and aquatic resources, caused by future changes in surface water hydrology within the Manteca WQCF project vicinity,have already undergone CEQA review(see Final EIR for Meeting Flow Objectives for the San Joaquin River Agreement 1999- 2010 [1999] and Supplemental EIS/EIR for Acquisition of Additional Water for Meeting the San Joaquin River Agreement Flow Objectives, 2001-2010 [2001])and,therefore, are not re-assessed in this EIR. These documents are hereby incorporated by reference into this EIR. Based on the above and the project description(see Chapter 3),the potential for the project to adversely affect fisheries and aquatic resources within the study area is via effects on water quality. Consequently, a thorough analysis of the project's effects on the water quality of the San Joaquin River in the vicinity of the discharge and at downstream Delta locations is presented in Section 4.9, "Hydrology and Water Quality."The methodology used for these water quality assessments is presented in Section 4.9 with additional detail provided in Appendix C (LWA 2007). Effects of project-related water quality on fish and other aquatic resources downstream of the Manteca WQCF discharge were evaluated based on appropriate water quality criteria for the protection of freshwater aquatic life and other relevant technical information as reported in scientific literature. Separate discussions for the assessment of conventional parameters and priority pollutants, and temperature are provided below. Conventional Parameters and Priority Pollutants A step-wise evaluation process was employed to assess the potential effects of conventional parameters(e.g.,pH, BOD,turbidity,nutrients, etc.) and priority pollutants under proposed project conditions (see Section 4.9). The first step involved evaluating compliance with applicable water quality criteria(CTR/NTR), water quality Manteca WQCF and Collection System Master Plans EIR EDAW City of Manteca 4.13-15 Fisheries and Aquatic Resources