State Water Project Long-Term Drought Plan

California Department of Water Resources (DWR) | May 21st, 2024

The 2024 State Water Project (SWP) Long-Term Drought Plan consolidates information and actions taken during past droughts along with descriptions of the actions taken by

The 2024 State Water Project (SWP) Long-Term Drought Plan consolidates information and actions taken during past droughts along with descriptions of the actions taken by the SWP to plan for and prepare for future droughts.

State Water Project Seismic Loading Criteria Report

California Department of Water Resources (DWR) | September 19th, 2012

Seismic loading criteria are developed for various types of structures in the State Water Project (SWP) to use in future designs and evaluations. The SWP system supplies

Seismic loading criteria are developed for various types of structures in the State Water Project (SWP) to use in future designs and evaluations. The SWP system supplies water for almost two third of Californians and about 750,000 acres of irrigated farmlands. It is critical for the California economy. Seismic risk is considered one of the greatest contributors of all potential risk categories for the SWP. California is considered one of most seismically vulnerable areas in the world and most of the SWP facilities are located in central and southern California, which are seismically active areas. The purpose of developing seismic loading criteria was to have an economically feasible SWP system that would provide adequate protection against the loss of life, property damage, and interruption of water delivery during and immediately after a seismic event. Most of the existing SWP facilities have not been evaluated since they were built in the 1960s. The knowledge of ground motion predictions and seismic analytical methodologies has significantly progressed since the1960s. As part of the development of the seismic loading criteria, current design standards used by Department of Water Resources (DWR), other similar agencies, and regulatory/code entities were gathered and utilized to select appropriate minimum loading levels for different types of SWP facilities. In addition, the process of criteria selection included consideration of the consequences of failure such as loss of life, property damage, and interruption of water delivery. The consequence of interruption of water delivery was somewhat difficult to quantify because DWR delivers water to the water contractors and they either store it in their storage facilities or distribute to the local agencies. The recommended loading criteria include consideration of consequences of failures in the selection process. The Division of Engineering (DOE) in DWR should use the seismic loading criteria recommended in this report for the design and evaluation of both new and existing SWP facilities. Seismic loading criteria is provided for most of the structures associated with the SWP—reservoirs , dams, canals, pipelines, tunnels, check structures, pumping and power plants, buildings, bridges and utility overcrossings of the aqueduct. The seismic loading criteria should be used for these structures and associated appurtenant facilities in the future. A project engineer can use a larger loading criteria than what is recommended in this report based on project specific factors such as: 1) the consequences of interruption of water delivery, 2) the impact on existing habitats and the environment, 3) the operational aspects of the facility in relation to water delivery, 4) the repair cost and time to return the system back to operational status, and 5) the availability of an emergency back-up system to temporarily make the facility operational until all the repairs are completed. The criteria recommended in this report are considered current; however, these seismic loading criteria should be reviewed and updated every five years to make appropriate changes based on future operational requirements and on changes in state-of-practice. This is the first time DWR has developed loading criteria for the entire SWP facility and many of these facilities have not been evaluated to determine how vulnerable the system would be based on any seismic criteria. Therefore, these criteria are considered preliminary until the recommendations can be confirmed to be reasonable for the SWP facilities.

State Water Project Table A Allocations 1967-1995

California Department of Water Resources (DWR) | January 14th, 2022

Summary Report on the Transactions of the Smelt Working Group in Water Year 2014

Delta Stewardship Council (Delta Council) | August 29th, 2014

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opi

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opinion on the Central Valley Project (CVP) and State Water Project (SWP) Long‐term Operations (BiOp) in Water Year (WY) 2014. In addition to background information pertinent to implementation of the BiOp , this report provides a summary of the transactions of the Smelt Working Group (SWG), as well as water operations and during WY 2014. The SWG is a technical team that evaluates biological and technical issues regarding Delta Smelt (Hypomesus transpacificus) and develops recommendations for consideration by the Service during implementation of the BiOp’s Reasonable and Prudent Alternative (RPA) actions. During WY 2014 the SWG made no recommendations for more restrictive water operations and the Service issued no determinations to reduce water exports.

System Reoperation Study, Phase 1: Plan of Study

California Department of Water Resources (DWR) | June 16th, 2011

System reoperation is generally defined as changing the operational and management procedures of existing water system facilities to obtain water resources related benefi

System reoperation is generally defined as changing the operational and management procedures of existing water system facilities to obtain water resources related benefits. Reoperation is considered an alternative to constructing major new facilities, although it may consist of physical modification of existing facilities. The specifics associated with a system reoperation strategy will vary among water purveyors depending upon the complexity of their system and their interest in participating in local and or interregional efforts. There may be opportunity to reoperate portions of California’s statewide water system to yield increased water resources related benefits. This opportunity was recently recognized by the State Legislature in Senate Bill X2 1 (SB X2 1) (Perata, 2008 – Water Code Section 83002.5), which 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 incorporate appropriate climate change strategies and be designed to determine the potential to achieve the following objectives: (I) 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. (II) Reoperation of existing reservoirs, flood facilities, and other water facilities in conjunction with groundwater storage to improve water supply reliability, flood hazard reduction, and ecosystem protection and to reduce groundwater overdraft. (III) Promotion of more effective groundwater management and protection and greater integration of groundwater and surface water resource uses. (IV) Improvement of existing water conveyance systems to increase water supply reliability, improve water quality, expand flood protection, and protect and restore ecosystems. RELATED DOCUMENTS: 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

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

California Department of Water Resources (DWR) | March 3rd, 2014

The System Reoperation Study is designed to identify potential options for the reoperation of the state’s flood control and water supply systems to meet the following o

The System Reoperation Study is designed to identify potential options for the reoperation of the state’s flood control and water supply systems to meet the following objectives: Water supply reliability Flood hazard reduction Ecosystem protection and restoration Reoperation options include integration of flood control and water supply systems, effective conjunctive management, and improvements to existing water conveyance systems. This phase of the analysis focuses on integration of flood control enhancing water supply systems and expanded conjunctive management with existing conveyance systems. An analysis was designed and performed with the goal of identifying potential reoperation options and to improve understanding of existing system constraints. The analysis is referred to as the tradeoff analysis in recognition of the fact that the existing flood control/water supply system is highly integrated and currently operated to meet water supply, flood control, and ecosystem purposes. Current system operations are complex and frequently constrained by flood control and ecosystem requirements and water rights and contracts for the beneficial use of water. Therefore, reoperation options designed to meet one of the three objectives of the System Reoperation Study frequently create tradeoffs with the other objectives. For example, reductions in required reservoir space for flood control may improve water supply reliability but increase risk of flood damage. The tradeoff analysis is a reconnaissance-level study designed to help illustrate how operational changes designed for one purpose can affect other objectives. Because the existing reservoir and conveyance system is highly integrated and constrained, changes in operation for one purpose create tradeoffs with other purposes. A reconnaissance-level study can help identify these tradeoffs, some of which may be unexpected or unintended, and thereby help guide refinement of more promising options. Model simulations performed in the tradeoff analysis are not refined for the purpose of quantifying benefits or impacts, but rather are intended to illustrate how operational changes in one area affect other areas. For example, how Central Valley Project (CVP) operations can affect State Water Project (SWP) operations, and vice versa. 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

System Reoperation Study, Phase 2: Strategy Formulation and Refinement

California Department of Water Resources (DWR) | March 3rd, 2014

The California Department of Water Resources (DWR) is conducting a system reoperation study (SRS) in cooperation with other State and federal agencies, local water distri

The California Department of Water Resources (DWR) is conducting a system reoperation study (SRS) in cooperation with other State and federal agencies, local water districts, groundwater managers, and other stakeholders, to identify potential strategies for reoperation of the statewide flood protection and water supply systems. The opportunity to reoperate portions of California’s statewide water system to yield increased water resources-related benefits was recognized by the State Legislature in Senate Bill X2 1 (SB X2 1) (Perata, 2008 – Water Code Section 83002.5). California’s statewide water system is comprised of a multitude of local, state, and federal projects. These projects include facilities such as dams and reservoirs, hydropower plants, canals, and water diversion structures. Many of these facilities were developed in the early to mid-20th century, and were not designed, constructed, or operated as an integrated water supply and flood management system. Over time, operations of the two largest water supply projects, the State Water Project (SWP), operated by DWR and the Central Valley Project (CVP), operated by the U.S. Department of the Interior’s Bureau of Reclamation (Reclamation), have been integrated to a certain degree. California’s water supply and flood management infrastructure is physically interconnected to the extent that it is technically feasible to move water around the system from Trinity County in the north to Imperial County in the south. However, the management of the water system is not as well integrated as it could be. The underlying logic of the SRS is that California can do much more with its existing water infrastructure by taking advantage of the physical interconnections (and enhancing them) while also operating the system in a coordinated manner to optimize the benefits. The current focus of the SRS is the Central Valley because this region has the highest integration of water supply and flood management facilities. Additionally, the greatest potential for ecosystem restoration through infrastructure reoperation is found in the Central Valley because the existing infrastructure has had a profound effect on aquatic ecosystems. 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

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

California Department of Water Resources (DWR) | August 21st, 2017

The California Department of Water Resources (DWR) is conducting a System Reoperation Study (SRS) in cooperation with other State and federal agencies, local water distri

The California Department of Water Resources (DWR) is conducting a System Reoperation Study (SRS) in cooperation with other State and federal agencies, local water districts, groundwater managers, and other stakeholders, to identify potential strategies for reoperation of the statewide flood protection and water supply systems. The opportunity to reoperate portions of California’s statewide water system to yield increased water resources-related benefits was recognized by the State Legislature in Senate Bill X2 1 (SB X2 1) (Perata 2008). In support of the legislative objectives, DWR developed the SRS to identify viable reoperation strategies and understand how integrated management can: • Improve the reliability of municipal and irrigation water supply. • Reduce flood hazards. • Restore and protect ecosystems. • Buffer the hydrologic variations expected from climate change. • Improve water quality. California’s statewide water system is composed of a multitude of local, State, and federal projects. These projects include dams and reservoirs, hydropower plants, canals, and water diversion structures. Many of these facilities were developed in the early to mid-20th century, and were not designed, constructed, or operated as an integrated water supply and flood management system. Over time, operations of the two largest water supply projects, the State Water Project (SWP), operated by DWR, and the Central Valley Project (CVP), operated by the U.S. Department of the Interior’s Bureau of Reclamation (Reclamation), have been integrated to a certain degree. California’s water supply and flood management infrastructure is physically interconnected to the extent that it is technically feasible to move water around the system, from Trinity County in the north to Imperial County in the south. However, the management of the water system is not as well integrated as it could be. The underlying logic of the SRS is that California can do much more with its existing water infrastructure by taking advantage of the physical interconnections (and enhancing them) while also operating the system in a coordinated manner to optimize the benefits. The current focus of the SRS is the Central Valley, because this region has the highest integration of water supply and flood management facilities. Additionally, the greatest potential for ecosystem restoration through infrastructure reoperation is found in the Central Valley, because the existing infrastructure has had a profound effect on aquatic ecosystems. Figure ES-1 shows the location of the Central Valley and the study area for the SRS. Figure 1-1 also shows major features of the CVP and SWP. 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

System Reoperation, Phase 3 Appendix D: Ecosystem Evaluation

California Department of Water Resources (DWR) | August 21st, 2017

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 prot

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

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

California Department of Water Resources (DWR) | August 21st, 2017

The California Department of Water Resources (DWR) is conducting a system reoperation study (SRS) in cooperation with other state and federal agencies, local water distri

The California Department of Water Resources (DWR) is conducting a system reoperation study (SRS) in cooperation with other state and federal agencies, local water districts, groundwater managers, and other stakeholders to identify potential strategies for reoperation of the statewide flood protection and water supply systems. The opportunity to reoperate portions of California’s statewide water system to yield increased water resources–related benefits was recognized by the State Legislature in Senate Bill (SB) X2 1 (Perata, 2008 – Water Code Section 83002.5). In support of the legislative objectives, DWR developed the SRS to identify viable reoperation strategies and understand how integrated management can: • Improve the reliability of municipal and irrigation water supply • Reduce flood hazards • Restore and protect ecosystem function and habitat conditions • Buffer the hydrologic variations expected from climate change • Improve water quality A component of the SRS is to evaluate how operational improvements of the state and federal water Projects in California may increase water supply and enhance ecosystem function and habitat. The Central Valley Project (CVP) generally has more storage and less conveyance flexibility; the opposite is generally true for the State Water Project (SWP). The SWP and CVP are operated by DWR and the U.S. Bureau of Reclamation (Reclamation), respectively. The operation of the two Projects is coordinated in accordance with the 1986 Coordinated Operating Agreement and other agreements. Though the operation is coordinated, the SWP and CVP are operating as two distinct units. They each have different contractual obligations and operating constraints. Operational improvements using strengths and assets of both Projects may result in improved operational efficiency and help achieve goals of the SRS. The purpose of this effort is to assess potential benefits of operating the SWP and CVP as a single, integrated Project. 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