California’s Agricultural and Urban Water Supply Reliability and the Sacramento–San Joaquin Delta

University of California, Davis (UC Davis) | October 13th, 2016

Much of the water supplied in California for agriculture and cities is taken directly from the Sacramento–San Joaquin Delta (Delta) or indirectly from surface and groun

Much of the water supplied in California for agriculture and cities is taken directly from the Sacramento–San Joaquin Delta (Delta) or indirectly from surface and groundwater diversions upstream. These water supplies have great economic and social value, and considerable ecosystem effects. Long thought of as the major source of water for economic growth in California, the reliability of water supplied from the Delta is threatened by drought, flood, climate change, earthquakes, growing water demands, and deteriorating conditions for endangered species and native ecosystems. Research in recent years has improved understanding of how management of the Delta ties together the quantity and quality of water available statewide. These ties run from the Sierra mountains and coastal streams, through the Central Valley, to the San Francisco Bay Area, and over the Tehachapi Mountains to southern California. For decades, Californians counted on reducing Delta outflows to supply water for growing water demands in its watershed and in water importing areas. With greater competition for water, concern for environmental effects, and a changing climate, the reliability of such supplies is now diminishing. This must lead to tighter accounting and modeling of water supplies in the Delta and throughout its watershed. This paper reviews issues about Delta water supplies, operations, regulations, and reliability; the economic value of supply; costs of unreliability in quantity and quality; and several directions for further scientific and technical work on water supply reliability.

CalSim 3 Results for 2070 Climate Change and Sea Level Projections and Sensitivity Analysis

California Department of Water Resources (DWR) | January 17th, 2024

This Technical Memorandum (TM) summarizes the key findings from a sensitivity analysis performed to analyze operations of the proposed Delta Conveyance Project (DCP) and

This Technical Memorandum (TM) summarizes the key findings from a sensitivity analysis performed to analyze operations of the proposed Delta Conveyance Project (DCP) and potential project water supply benefits under a range of potential scenarios for 2070 conditions. These scenarios consider climate change, sea level rise (SLR), and various water management responses. In addition, this sensitivity analysis also helps to identify whether proposed project operations and potential project impacts detailed in the Final DCP Environmental Impact Report (EIR) would remain similar or differ under a different climate change and SLR scenario under 2070 conditions, a more distant future.

Carriage Water

California Department of Water Resources (DWR) | September 26th, 2001

Carriage water is defined as marginal export costs, that is, the extra water needed to carry a unit of water across the Delta to the pumping plants while maintaining a co

Carriage water is defined as marginal export costs, that is, the extra water needed to carry a unit of water across the Delta to the pumping plants while maintaining a constant salinity. Or more practically, when the exports are increased by one unit, the Sacramento flow is increased by one unit plus carriage water to maintain a constant Delta salinity. It has been known for several years that the current method of estimating carriage water in DWRSIM, called the Minimum Delta Outflow (MDO) Routine, is not particularly accurate in individual years and a better method needed. The Delta is a complex system and past attempts at developing a useful method for measuring carriage water and ultimately an MDO replacement always had at least one major flaw. An attempt was made to search for carriage water directly in the historical data, that is, to find a period of time when Net Delta Outflow (NDO) is fairly constant, but Sacramento flow and exports are increasing. If carriage water existed, salinity at interior Delta stations should increase. While there are a few times when this seems to be true (e.g. summer 1979 and 1994), the salinity increase could also be explained by antecedent conditions, that is, previous to the period of constant NDO, NDO was much higher, and the salinity increase could be simply due to the Delta gradually reaching new equilibrium. Thus it became apparent that only a model of the Delta could say anything about carriage water.

Central Valley Flood Protection Plan: Conservation Strategy

California Department of Water Resources (DWR) | August 8th, 2017

In the Central Valley of California, flood risks, water supplies, and the functioning of ecosystems are linked, with actions in one area affecting the other areas. The ma

In the Central Valley of California, flood risks, water supplies, and the functioning of ecosystems are linked, with actions in one area affecting the other areas. The majority of flows that pass through the State Plan of Flood Control (SPFC) are regulated by reservoirs operated for flood management, water supply, water quality, power generation, wildlife and fisheries habitat, and recreation. Similarly, the system of river and bypass channels, levees, and water control structures in the Central Valley does more than just contain floodwaters that previously flooded the valley floor for months at a time. It supports agricultural uses in the bypasses, serves as valued recreational areas and open space, helps in the management of surface water supplies and management of groundwater and water quality, and provides critical remnant riparian and floodplain habitats for numerous fish and wildlife species. The Central Valley Flood Protection Plan (CVFPP) recognizes these interconnections in its approach to flood management. The CVFPP is a long-term planning document that provides a framework for prioritization of investments in the SPFC. It seeks to improve flood risk management (the primary goal), as well as improve operations and maintenance (O&M), promote ecosystem functions, improve institutional support, and promote multi-benefit projects where feasible (supporting goals) (California Department of Water Resources [DWR] 2012a). This Conservation Strategy (or Strategy) is an integral part of the CVFPP. It supports the attainment of all CVFPP goals, but focuses on the improvement of ecosystem functions through the integration of ecological restoration with flood risk reduction projects where feasible. This Conservation Strategy, including Appendices A-L, describes the basis for recommending various conservation actions and setting long-term objectives for the Central Valley flood management system as a whole. The integration of specific environmental restoration features with DWR’s proposed flood management system improvements is summarized in Chapters 2 and 3 of the CVFPP and will also be described further in the 2017 CVFPP update and supporting documents, such as the Sacramento River Basin-Wide Feasibility Study (BWFS) and the San Joaquin River BWFS. The Conservation Strategy and CVFPP as a whole would contribute to achieving the California Water Action Plan’s overarching goals of  reliability, restoration, and resilience (California Natural Resources Agency, California Department of Food and Agriculture, and California Environmental Protection Agency 2015, 2016). In particular, this Strategy and the CVFPP as a whole are integral to three of the 10 “key actions” identified in the California Water Action Plan: Increase flood protection. Protect and restore important ecosystems. Increase operational and regulatory efficiency. Note: This document has extensive appendices and errata. Appendix A: Regulatory Setting, Appendix B: Advance Mitigation; Appendix C: Description of Construction Activities for Structural Modifications; Appendix D: Vegetation Management Strategy; Appendix E: Invasive Plant Management Plan; Appendix F: Existing Conditions; Appendix G: Identification of Target Species and Focussed Conservation Plans; Appendix H: Central Valley Chinook Salmon Rearing Habitat Needed to Satisfy the Anadromous Fish Restoration Program (AFRP) Doubling Goal; Appendix I: Floodplain Restoration Opportunities Analysis; Appendix J: Existing Conservation Objectives from other Plans; Appendix K: Synthesis of Fish Migration Improvement Opportunities in the Central Valley Flood System; Appendix L: Measurable Objectives Development - Summary of Conservation Needs and Scale of Restoration Opportunities; 2016 CVFPP Conservation Strategy: Errata; Conservation Strategy Development Process Overview

Central Valley Project (CVP) Water Contracts Fact Sheet

U.S. Bureau of Reclamation (USBR) | April 6th, 2016

Reclamation fact sheet on the Central Valley Project water contracts.

Reclamation fact sheet on the Central Valley Project water contracts.

Central Valley Project and State Water Project Drought Operations Plan and Operational Forecast April 1, 2014 through November 15, 2014

Delta Stewardship Council (Delta Council) | April 8th, 2014

Central Valley Project Improvement Act Implementation Plan For Fish Programs

U.S. Bureau of Reclamation (USBR) | July 20th, 2015

The purpose of this Plan is to describe the approach for prioritizing and implementing the anadromous fish-related provisions under the CVPIA over the next 5-10 years. Th

The purpose of this Plan is to describe the approach for prioritizing and implementing the anadromous fish-related provisions under the CVPIA over the next 5-10 years. This Plan will build upon the Final Restoration Plan (FRP, USFWS 2001) to integrate a decision-making framework across all programs with the goal of making all reasonable efforts to at least double natural production of anadromous fish in California’s Central Valley on a long-term, sustainable basis. The Plan develops an annual process for setting priorities and funding projects across CVPIA fish-related provisions and watersheds in the Central Valley. The new process uses an Adaptive Resource Management (ARM) approach with support from Decision-Support Models (DSMs) to prioritize implementation of management actions that have the highest probability of achieving biological objectives for wild populations of native anadromous fish. The ARM approach will also guide plans for monitoring and research by synthesizing existing monitoring data, annually updating DSMs using new information, and estimating the value of new information to the decision making process.

Central Valley Project Municipal and Industrial Water Shortage Policy Guidelines and Procedures

U.S. Bureau of Reclamation (USBR) | February 2nd, 2017

The Bureau of Reclamation (Reclamation) prepared the Central Valley Project (CVP) Municipal and Industrial (M&I) Water Shortage Policy (WSP) Environmental Impact Stat

The Bureau of Reclamation (Reclamation) prepared the Central Valley Project (CVP) Municipal and Industrial (M&I) Water Shortage Policy (WSP) Environmental Impact Statement (EIS) to evaluate the potential impacts of CVP M&I WSP alternatives. A Record of Decision was signed on November 13, 2015, to implement Alternative 4 (Appendix A), Updated M&I WSP (preferred alternative). The purposes of the M&I WSP are to: Define water shortage terms and conditions for applicable CVP Contractors. Determine the quantity of water made available to CVP Contractors from the CVP that; together with the M&I Contractors’ drought water conservation measures and other Non-CVP water supplies, would assist the M&I Contractors in their efforts to protect public health and safety (PHS) during severe or continuing droughts. Provide information to Contractors for their use in water supply planning and development of drought contingency plans.

Central Valley Project Operations, Total Water Management Study, Central Valley Basin, California

U.S. Bureau of Reclamation (USBR) | January 1st, 1975

Central Valley Project Water Supply and Yield Study

U.S. Bureau of Reclamation (USBR) | December 26th, 2007

The CALFED Bay-Delta Authorization Act, Title 1 of Public Law 108-361 (the Water Supply, Reliability, and Environmental Improvement Act of 2004) directed the Secretary of

The CALFED Bay-Delta Authorization Act, Title 1 of Public Law 108-361 (the Water Supply, Reliability, and Environmental Improvement Act of 2004) directed the Secretary of the Interior (Secretary), acting through the Bureau of Reclamation (Reclamation), to conduct a study of available water supplies and existing and future needs for water in the State of California. The Secretary is to prepare a report identifying possible projects and water management actions that could provide new firm yield and water supply improvements for the CVP. The Secretary is also required to incorporate and revise, as necessary, the results of the 1995 Least-Cost CVP Yield Increase Plan originally required by section 3408(j) of Central Valley Project Improvement Act (CVPIA) of 1992. The purpose of this Water Supply and Yield (WSAY) Study is to identify the following: 1. Opportunities for new firm yield and water supply improvements for CVP water service contractors (entities with contracts for the delivery of CVP water) 2. Water management actions or projects that would improve firm yield for the CVP while balancing the available supplies with existing demands 3. The financial costs of the water management actions or projects 4. Beneficiaries and beneficiaries’ willingness to pay for identified improvements