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 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

Systematic Screening of Dams for Environmental Flow Assessment and Implementation

Bioscience (Oxford University Press) | November 30th, 2014

Technical Report on the Scientific Basis for Alternative San Joaquin River Flow and Southern Delta Salinity Objectives

California State Water Resources Control Board (SWRCB) | February 15th, 2012

The State Water Resources Control Board (State Water Board) is in the process of reviewing the San Joaquin River (SJR) flow objectives for the protection of fish and wild

The State Water Resources Control Board (State Water Board) is in the process of reviewing the San Joaquin River (SJR) flow objectives for the protection of fish and wildlife beneficial uses, water quality objectives for the protection of southern delta agricultural beneficial uses, and the program of implementation for those objectives contained in the 2006 Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (2006 Bay- Delta Plan). Figure 1.1 displays the project area corresponding to SJR flow objectives and program of implementation and Figure 1.2 displays the project area for the southern Delta water quality objectives and program of implementation. The information and analytical tools described in this report (referred to hereafter as Draft Technical Report or Technical Report) are intended to provide the State Water Board with the scientific information and tools needed to consider potential changes to these objectives and their associated program of implementation. In this quasi-legislative process, State Water Board staff will propose amendments to the SJR flow objectives for the protection of fish and wildlife beneficial uses, southern Delta water quality objectives for the protection of agricultural beneficial uses, and the program of implementation contained in the 2006 Bay-Delta Plan. Also, the environmental impacts of these amendments will be evaluated in a Substitute Environmental Document (SED) in compliance with the California Environmental Quality Act. Any changes to water rights consistent with the revised program of implementation will be considered in a subsequent adjudicative proceeding.

Technologies for Passing Fish at Large Dams

California Department of Water Resources (DWR) | June 1st, 2013

Given the possible conditions that may exist in Central Valley streams as the climate warms, many researchers and agencies have recognized the need to evaluate opportunit

Given the possible conditions that may exist in Central Valley streams as the climate warms, many researchers and agencies have recognized the need to evaluate opportunities to provide Central Valley salmonid species access to currently inaccessible habitat (DWR 2008, NMFS 2009, and CA Resources Agency 2009). In addition, Lindley et al. (2007) stated that in order to recover Central Valley salmonids, some populations will need to be established in areas now blocked by dams. “The state should work with dam owners and operators, federal resource management agencies, and other stakeholders to evaluate opportunities to introduce or reintroduce anadromous fish to upper watersheds. Reestablishing anadromous fish, such as salmon, upstream of dams may provide flexibility in providing cold water conditions downstream, and thereby help inform system reoperation.” (CA Resources Agency 2009) The U.S. Bureau of Reclamation dedicates over 1.2 million acre-feet of water, through operation of the Central Valley Project, to fish and wildlife. DWR releases water to meet minimum flow and temperature requirements downstream of Oroville Dam. Climate change may warm rivers and streams, with less water available for ecosystem flow and temperature needs in spring and summer (CA Resources Agency 2009). As temperatures warm, more cold water storage may be needed so that releases can be made to meet temperature requirements downstream. Providing anadromous1 fish passage to areas upstream of reservoirs could eliminate or reduce the need for cold water releases and give water managers additional flexibility in meeting downstream water supply and flood protection needs. In addition, it is prudent to consider fish passage opportunities as part of potential systems reoperations because other agencies are conducting planning efforts for fish passage ...

Term 91: Stored Water Bypass Requirements

California State Water Resources Control Board (SWRCB) | April 8th, 2012

Pursuant to numerous Board decisions (D-1485, D-1641, Order 2001-05), the Projects are required to release stored water to meet water quality standards in the Delta (incl

Pursuant to numerous Board decisions (D-1485, D-1641, Order 2001-05), the Projects are required to release stored water to meet water quality standards in the Delta (including flow and salinity standards) where natural flows are insufficient. The obligation was originally placed on the Projects as an interim measure pending future studies of how the obligation to meet water quality standards would be shared with other appropriators. In return for resolving Project protests on subsequent applications to appropriate water, Term 91 was developed and made a condition to permits issued after 1965. Term 91 prohibits diversions by these Permittees when natural and abandoned flows to the Delta are insufficient to meet the water quality standards and the Projects are supplementing such flows with previously stored water to meet the standards. The purpose of this report is to explore the enhanced use and more vigorous enforcement of diversion curtailments as a means to achieve flow standards. This subject matter is relevant to the Delta even through the Projects are under a present and legal obligation to meet existing flows standards.

The 1976-1977 California Drought - A Review

California Department of Water Resources (DWR) | May 1st, 1978

This is the fifth and final Department of Water Resources' report on the 1976-1977 California drought, the worst in the State's history, which saw 1976, the fourth-driest

This is the fifth and final Department of Water Resources' report on the 1976-1977 California drought, the worst in the State's history, which saw 1976, the fourth-driest year of record, give way to 1977, the driest ever.  These reports provide the most comprehensive documentation of a drought in history. The 1976-1977 drought has again shown the finite nature of our resourcees and our limited ability to control nature.  This report, prepared by the Department's Drought Information Center, updates the August 1977 report and places the entire two-year period in perspective.  It documents the impact of the drought and details the response by federal, State, and local governments and the public. This report also discusses lessons learned from the drought and suggest future actions to enable us to better use our State's limited water resources.

The Decline of Striped Bass in the Sacramento-San Joaquin Estuary, California

American Fisheries Society (AFS) | July 1st, 1985

The abundance of young striped bass Morone saxatilis in the Sacramento-San Joaquin Estuary has suffered an unsteady but persistent decline from population levels that wer

The abundance of young striped bass Morone saxatilis in the Sacramento-San Joaquin Estuary has suffered an unsteady but persistent decline from population levels that were high in the middle 1960s. The decline was particularly severe in 1977 and abundance of young striped bass has been low every subsequent year. The adult striped bass population also has fallen during the past 20 years, but the exact period over which the decline occurred and the rate of decline are not clear. The adult population is now about one-quarter of its former size and there is little sign of recovery. We believe the Sacramento-San Joaquin striped bass population and the fishery that it supports are in serious danger. The cause is most likely one or more of four factors. (1) The adult population is now so low that egg production may be inadequate. (2) The plankton food supply of young striped bass in the western Sacramento-San Joaquin Delta and Suisun Bay has been greatly reduced each spring. Diversion of water from the delta for agricultural purposes is a prime suspect for the decrease in food production. (3) Large numbers of young fish are lost by entrainment in water diversions. (4) The population is stressed by toxic substances such as petrochemicals and pesticides. Additional studies are underway to help determine the principal cause(s) of the striped bass decline.

The Delta Pool

State of California | January 2nd, 1961

The Draft State Water Project Delivery Capability Report 2021

California Department of Water Resources (DWR) | December 31st, 2021

The California Department of Water Resources (DWR) has authority under state law to construct, operate, and maintain the State Water Project (SWP) to manage, store and de

The California Department of Water Resources (DWR) has authority under state law to construct, operate, and maintain the State Water Project (SWP) to manage, store and deliver water for the benefit of the State. This report is intended to provide information about the key factors affecting the operation of the SWP in California, its long-term capability as a source of water for beneficial use, and an estimate of its current delivery capability. This report meets the requirements of Attachment B to the Monterey Plus Settlement Agreement of May 2003. Water provided by the SWP is a major source of the water supplies available to many SWP contractors. SWP contractors consist of 29 public entities that include cities, counties, urban water agencies, and agricultural irrigation districts. SWP contractors’ local/-regional water users have long-term contracts with the DWR for all, or a portion of their water supply needs. Thus, the delivery capability of water from the SWP system is an important component in the water supply planning of its recipients, and ultimately affects the amount of water available for beneficial use in California. The availability of these water supplies may be highly variable. A sequence of relatively wet water years1 may be followed by a varying sequence of dry or critically dry years. Having good and reliable estimates on how much water each contractor will receive each year —- whether it be a wet water year, a critical year, or somewhere in between -- gives contractors a better sense of the degree to which they may need to implement increased conservation measures, or plan for new facilities or back up sources of water to meet their needs. The geography of California and the infrastructure of water transfer from the source areas, located in the Sierra Mountain Range, to areas of demand for water, makes the Sacramento-San Joaquin Delta a key feature of the SWP’s ability to deliver water to its agricultural and urban contractors in the North Bay, the South Bay, California Central Valley, and Southern California. All but five of the 29 SWP contractors receive water deliveries by diversions from the Delta. These water diversions are pumped by either the Harvey O. Banks or Barker Slough pumping plants. DWR and the United States Bureau of Reclamation (USBR), the managing entities of the two statewide systems of water transfer in California, face numerous challenges in the operation of their diversion facilities in the Delta, and are regulated by several state and federal agencies to maintain, and enhance the Delta’s long-term sustainability. Maintaining suitable quality of water flowing in the channels of the Delta for the numerous in-basin beneficial uses, and the protection of endangered and threatened fish species are important factors of concern for the operators of the Delta export diversion facilities. Ongoing regulatory restrictions, such as those aimed at protecting the estuary’s resident and migratory fish species, are major challenges to a reliable and sustainable water delivery capability of both, SWP and the Central Valley Project (CVP) systems. Complications induced by climate change also pose the threat of increased variability in the frequency and magnitude of floods and droughts. The projected sea level rise caused by the increase in average temperature complicate efforts to manage salinity levels in the channels affected by tides. Additionally, higher ocean levels could result in more frequent water quality degradation in the Delta channels requiring additional Delta outflow to maintain water quality objectives. The 2021 Final Main Report (released at the end of March 2022) may include further information on climate change. Previously, the climate change scenario results were only discussed and presented in the Technical Addendum which is not published during the draft phase of the Delivery Capability Report (DCR). Other challenges include continued subsidence of Delta islands, many of which are already below sea level and supported by relatively unstable levee systems. Thus, the threat of a catastrophic levee failure becomes more significant as water pressure increases against the already fragile levees. The analyses in this report factor in all the current regulations governing SWP and CVP operations in the Delta and assumptions about water uses upstream in the Sacramento River and San Joaquin River watersheds. Analyses were conducted that determined the amounts of water that SWP contractors receive and the amounts of water they choose to hold for use in a subsequent year. SWP Delta exports have decreased since 2005, although the bulk of the change occurred between 2005 and 2009 and in 2019. The former reduction is due to the Delta regulations which constrained exports that culminated in the federal Biological Opinions (BiOps) which went into effect in 2008-2009. These BiOps restricted operations of the CVP and SWP diversion pumps. The later reduction is due to two main factors: 1) the amended Coordinated Operation Agreement (COA) with accompanying project operation changes which reduced SWP exports and increased CVP exports, and (2) a more conservative operation of Lake Oroville by the SWP. Many of the same assumptions on SWP operations described in the 2019 Report remains the same in this update for 2021, however, there were a few notable changes. These include the transition from CalSim II to CalSim 3 and CVP and SWP operational refinements. As a result, the differences between the 2019 and 2021 Reports can be attributed primarily to differences in hydrology, spatial and temporal expansion, more explicit groundwater and surface water interaction representation, and operational refinements. The most salient findings in this report are: Under existing conditions, the estimated average annual delivery of Table A water for this 2021 Report is 2,309 thousand acre-feet (TAF)/year, 105 TAF less than the 2,414 TAF/year estimated for the 2019 Report (Table 5-2). The likelihood of existing condition SWP Article 21 deliveries (supplemental deliveries to Table A water) being greater than 20 TAF/year has decreased by 20% relative to the likelihood presented in the 2019 Report (Figure 5-7).