San Joaquin River

Recent Scientific Contributions by the U.S. Geological Survey in the San Francisco Bay and Sacramento–San Joaquin Delta Estuary

U.S. Geological Survey (USGS) | January 26th, 2026

Recharge Area Identification, Utilization, and Protection Resource Management Strategy

California Department of Water Resources (DWR) | April 29th, 2024

This resource management strategy (RMS) advances water supply augmentation, resilience, and equity in California by providing summaries of the state of knowledge, applica

This resource management strategy (RMS) advances water supply augmentation, resilience, and equity in California by providing summaries of the state of knowledge, applications, and available information and resources on recharge area identification, utilization, and protection.

Recharge Net Metering to Enhance Groundwater Sustainability

University of California, Berkeley (UC Berkeley) | April 2nd, 2018

Groundwater sustainability depends on balancing aquifer inflows and outflows. Extraction (pumping of groundwater, typically for human use) and recharge (inflow of

Groundwater sustainability depends on balancing aquifer inflows and outflows. Extraction (pumping of groundwater, typically for human use) and recharge (inflow of water to an aquifer from the land surface and streams) are central components of this water balance. Often, increasing demands for groundwater are exacer- bated by stresses on limited surface water supplies. Changes in land use and shifting climate can result in less infiltration of precipitation into the ground, reducing recharge. Increasing water scarcity has led to increased pumping, and in turn, unsustainable management of groundwater in many basins, resulting in depleted supplies, degraded water quality, and other impacts.

Recommendations for a Modeling Framework to Answer Nutrient Management Questions in the Sacramento-San Joaquin Delta

San Francisco Estuary Institute (SFEI) | March 1st, 2016

Management actions in the Delta related to nutrients could cost billions of dollars to implement in the coming decades depending on decisions that will come before the Ce

Management actions in the Delta related to nutrients could cost billions of dollars to implement in the coming decades depending on decisions that will come before the Central Valley Regional Water Quality Control Board (Water Board). The complexity of the Delta ecosystem and the range of questions to be addressed demand that numerical, processed-based water quality modeling be part of Delta management efforts. In light of this fact, the Water Board convened the Modeling Science Workgroup in 2015, and tasked it with advising on the development and use of water quality models as one component of the Water Board’s Nutrient Research Plan. The Charge to the Modeling Science Workgroup (included in Appendix B) was to provide advice to the Water Board on:  · The types of models would be needed to answer the nutrient management questions raised by stakeholders,  · Organizational arrangements to support and maximize the benefits of models, and  · Cost estimates for the modeling task and how such work might be phased over time. 

Recommendations to the State Water Resources Control Board Pursuant to California Water Code Section 10609

California Department of Water Resources (DWR) | September 29th, 2022

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and

The Department of Water Resources (DWR) is pleased to provide the following recommendations developed in response to the 2018 Legislation (Senate Bill 606 [Hertzberg] and Assembly Bill 1668 [Friedman]) enacted in support of “Making Water Conservation a California Way of Life.” The Legislation included provisions for advancing urban water use efficiency through developing and implementing various water use efficiency standards, variances for unique uses of water, and commercial, industrial, and institutional (CII) performance measures, among other requirements. Full reports detailing our methods, technical analyses, studies, public input, and recommendations will follow. These recommendations for long-term urban water use efficiency reflect technical considerations, public input, and the imperative to continue California’s progress in urban efficient use of water for future generations. If adopted DWR's recommendations on outdoor residential and CII water use on landscapes with dedicated irrigation meters, combined with the indoor residential water use standard recommendations submitted to the Legislature jointly by DWR and State Water Resources Control Board (State Water Board), pursuant to Water Code 10609.4 (b)(1), would result in expected long-term water savings of approximately 450,000 acre-feet per year starting in 2030 – considering 2019 population and 2017-2019 water use data, the water savings are enough to supply about 1.6 million homes or 4.7 million residents for both indoor and outdoor annual water needs.

Record of Decision Friant-Kern Canal Middle Reach Capacity Correction Project

U.S. Bureau of Reclamation (USBR) | November 4th, 2020

The United States Department of the Interior, Bureau of Reclamation (Reclamation), as the Federal lead agency under the National Environmental Policy Act (NEPA), and Fria

The United States Department of the Interior, Bureau of Reclamation (Reclamation), as the Federal lead agency under the National Environmental Policy Act (NEPA), and Friant Water Authority (FWA) as the State lead agency under the California Environmental Quality Act (CEQA), prepared the Friant-Kern Canal Middle Reach Capacity Correction Project (Project) Environmental Impact Statement/Environmental Impact Report (EIS/EIR) to assess impacts of the Project. The Project is being proposed to restore the capacity of a 33-mile reach of the Friant-Kern Canal (FKC) to its original design and constructed conveyance capacity. Click here for a directory with links to the federal environmental documents for the Friant-Kern Canal Middle Reach Capacity Correction Project.

Record of Decision, Trump Administration Action 5 Operations Plan for the Central Valley and State Water Projects, per Executive Order 14181

U.S. Bureau of Reclamation (USBR) | December 4th, 2025

On January 24, 2025, President Donald J. Trump issued Executive Order 14181 “Emergency Measures To Provide Water Resources In California And Improve Disaster Response I

On January 24, 2025, President Donald J. Trump issued Executive Order 14181 “Emergency Measures To Provide Water Resources In California And Improve Disaster Response In Certain Areas.” A Presidential Memorandum titled “Putting People Over Fish” was signed four days before the Executive Order and references a reliable water supply, but the specific direction to the CVP is found in Executive Order 14181. Section 2 of Executive Order 14181 requires, among other measures, (c) The Secretary of the Interior, including through the Bureau of Reclamation, shall utilize his discretion to operate the CVP to deliver more water and produce additional hydropower, including by increasing storage and conveyance, and jointly operating federal and state facilities, to high­need communities, notwithstanding any contrary State or local laws. The Bureau of Reclamation shall take all available measures to ensure that State agencies — including the California Department of Water Resources — do not interfere with the Bureau of Reclamation’s operation of the project to maximize water delivery to high­need communities or otherwise, including but not limited to the issuance of a new Record of Decision maximizing water deliveries and consistent with the 2020 Record of Decision. Subsection (g) calls for a “proposed plan, for review by the Secretaries, to appropriately suspend, revise, or rescind any regulations or procedures that unduly burden such projects and are not necessary to protect the public interest or otherwise comply with the law.” This ROD implements initial actions in response to Executive Order 14181. Click here for the Reclamation Long Term Operations page,  here for response to the Trump Action 5 gambit from California Department of Water Resources, and here for the response from the State Water Resources Control Board

Recovery plan for Central Valley winter-run chinook salmon, spring-run chinook salmon, and steelhead

National Marine Fisheries Service (NMFS) | July 7th, 2014

Recovery is the process by which listed species and their ecosystems are restored and their future is safeguarded to the point that protections under the Endangered Speci

Recovery is the process by which listed species and their ecosystems are restored and their future is safeguarded to the point that protections under the Endangered Species Act (ESA) are no longer needed. The goal of this Recovery Plan is to recover the endangered Sacramento River winter-run Chinook salmon Evolutionarily Significant Unit (ESU), the threatened Central Valley spring-run Chinook salmon ESU, and the threatened California Central Valley steelhead Distinct Population Segment (DPS). Recovering these species and the Central Valley, San Francisco Bay-Delta Estuary, and Pacific Ocean ecosystems that support them will be challenging and will require shifts in societal values. Californians must work together towards a conservation ethic and practice that ensures wild salmon and steelhead are an important part of coastal California and Central Valley culture for many generations to come.

Recovery Plan for Sacramento-San Joaquin Delta native fishes

U.S. Fish and Wildlife Service (FWS) | November 26th, 1996

Eight fish species are included in the Sacramento-San Joaquin Delta Native Fishes Recovery Plan. The delta smelt is listed as a threatened species. The Sacramento splitta

Eight fish species are included in the Sacramento-San Joaquin Delta Native Fishes Recovery Plan. The delta smelt is listed as a threatened species. The Sacramento splittail (splittail) was proposed as a threatened species on January 6, 1994. This recovery plan will recommend restoration criteria for the splittail that would be appropriate recovery criteria should the species be listed. Longfin smelt, green sturgeon, spring-run, late fall-run, and San Joaquin fall-run chinook salmon are species of concern for which restoration criteria are recommended. Information is also included on Sacramento perch, a species believed to be extirpated from the Delta at this time. Habitat Requirements and Limiting Factors: The eight species included in this recovery plan depend on the Sacramento-San Joaquin Delta for a significant segment of their life history. Threats to the Delta ecosystem and these species include loss of habitat due to increased freshwater exports resulting in increased salinity, loss of shallow-water habitat due to dredging, diking and filling, introduced aquatic species that have disrupted the food chain, and entrainment (movement offish by currents produced by diversions) in State, Federal and private water diversion. State and Federal water projects have also changed the pattern and timing of flows through the Delta. The salmon races are affected by sport and commercial harvest as well as by interactions with hatchery stocks. Recovery and Restoration Objective: Delisting of delta smelt. Restoration of splittail, longfin smelt, green sturgeon, spring-run, late fall-run, San Joaquin fall-run chinook salmon, and Sacramento perch. Recovery and Restoration Criteria: Recovery criteria are quantifiable and species specific and can be used to (1) monitor effectiveness of recovery actions, (2) determine when a species has recovered to a secure level (stabilized), and (3) determine when a species qualifies for delisting. In many cases, criteria are based on two independent measures: population abundance and geographic distribution. For each species a historic base period was established using available data to characterize abundance and distribution during a pre-decline period. The time period over which abundance and distribution criteria must be met was set at five generations. For five of the eight species there is an additional requirement of meeting the criteria through a minimum number of years of stressful environmental conditions. Action Needed: 1. Enhance and restore aquatic and wetland habitat in the Sacramento-San Joaquin River estuary. 2. Reduce effects of commercial and recreational harvest. 3. Reduce effects of introduced aquatic species on Delta native fishes. 4. Change and improve enforcement ofregulatory mechanisms. 5. Conduct monitoring and research on fish biology and management requirements. 6. Assess recovery management actions and re-assess prioritization of actions. 7. Increase public awareness of importance of Delta native fishes.

Regional Governance of Flood Management in the Central Valley

California Department of Water Resources (DWR) | May 30th, 2014

California faces significant challenges in managing its highly variable water resources, particularly as climate change and a growing population exacerbate drought and fl

California faces significant challenges in managing its highly variable water resources, particularly as climate change and a growing population exacerbate drought and flood risks.  The California Department of Water Resources (DWR) and other state agencies have been encouraging integrated approaches to water management, taking into account the connections between water supply, water quality, flood protection, and ecosystem health. The recent California Water Action Plan calls for improved coordination between local, state and federal agencies and tribal governments in order to develop multi-­benefit water management strategies. Regional-­scale planning has become a crucial avenue for advancing these efforts. Initiated in 2002, the Integrated Regional Water Management Planning (IRWM) process has led to the formation of 48 water planning regions statewide, in which diverse local agencies have developed integrated plans for managing all aspects of a region’s water management. More recently, a Regional Flood Management Planning (RFMP) process was created in the context of the Central Valley Flood Protection Plan to advance integrated approaches to reducing flood risks. Six flood planning regions, overlapping with nine IRWM regions, were formed in 2012. This study analyzes the origins and functioning of the IRWM and RFMP processes, and the degree of coordination between them to address flood risks in the Central Valley. In particular, it examines how each is working to generate multi-­benefit strategies, and how they account for climate change. It also discusses opportunities for future coordination between the IRWM and RFMP processes, and DWR’s role in supporting this. This study is primarily based upon an analysis of publicly available documents related to the IRWM and RFMP processes. It is also informed by meeting observations and conversations with staff at DWR and the Central Valley Flood Protection Board, and participants in IRWM and RFMP processes. Since RFMPs were not yet completed at the time of this writing, this study’s findings are preliminary. Nonetheless, this report provides an indication of the overall functioning of these RFMP and IRWM regions, and some general considerations for DWR as it assesses next steps in supporting these programs.