System Reoperation, Phase 3 Appendix D: Ecosystem Evaluation

Senate Bill (SB) X2 1 mandated and allocated resources for “planning and feasibility studies to identify potential options for the reoperation of the state’s flood protection and water supply systems that will optimize the use of existing facilities and groundwater storage capacity.” Specifically, SB X2 1 stipulated that the studies shall be designed to determine the potential to achieve integration of flood protection and water supply systems to increase water supply reliability and flood protection, improve water quality, and provide for ecosystem protection and restoration. For this evaluation, a suite of ecosystem evaluation metrics were developed to evaluate the effects of reoperation scenarios simulated in Phases II and III of the SRP.

Phase II reoperation scenarios were used to develop and test the ecosystem evaluation framework, and to quantify the effects of reoperation at Shasta and Oroville paired with conjunctive use and spring pulse flows. The next step was studying the ecosystem effects of Forecast-Based-Operation (FBO) at Shasta and Oroville combined with conjunctive use and spring pulse flows. Finally, t additional scenarios were developed and evaluated to explore the sensitivity of ecosystem performance to FBO and the potential for reoperation to enhance major ongoing ecosystem restoration efforts in the system. The purpose of this report is to document and describe the methods and results from the ecosystem evaluation to date, and to outline additional steps that could optimize reoperation scenarios for ecosystem improvement.

RELATED DOCUMENTS:

System Reoperation Study, Phase 1: Plan of Study

System Reoperation Study, Phase 2: Strategy Formulation and Refinement

System Reoperation Study, Phase 2: Appendix A: Forecast?Based Operations Analysis

System Reoperation Study, Phase 2: Appendix B: Tradeoff Analysis

System Reoperation Study, Phase 3 Report: Assessment of Reoperation Strategies

System Reoperation, Phase 3: Appendix C: State Water Project and Central Valley Project Integrated Operations Analysis

System Reoperation, Phase 3 Appendix D: Ecosystem Evaluation