SacPAS Fish Model: A model for emergence, migration and survival of Sacramento River salmon

Delta Stewardship Council (Delta Council) | November 1st, 2017

Sacramento and San Joaquin Basins Climate Impact Assessment

U.S. Bureau of Reclamation (USBR) | September 8th, 2014

Through West-Wide Climate Risk Assessments (WWCRAs) conducted under that program, Reclamation is conducting reconnaissance-level assessments of risks to water supplies an

Through West-Wide Climate Risk Assessments (WWCRAs) conducted under that program, Reclamation is conducting reconnaissance-level assessments of risks to water supplies and related resources in eight major Reclamation river basins in the Western United States. This report presents the results of the Sacramento and San Joaquin Climate Impact Assessment (SSJIA), which addresses impacts in two of these major basins in California. The SSJIA also includes the Tulare Lake Basin in the southern part of the Central Valley of California; part of the Trinity River watershed from which some water is diverted into the Central Valley; and a portion of California’s central coast region where Central Valley Project (CVP) and State Water Project (SWP) water supplies are delivered. The water supplies and demands analyzed in the SSJIA include CVP water users, SWP water users, and the other non-project water users in the study area. Included in the report is an overview of the current climate and hydrology of California’s Central Valley (Sacramento, San Joaquin and Tulare Lake Basins), an analysis of observed trends in temperature and precipitation over historical record, and a comparison of these trends to future water operation projections not considering climate change. The report then presents hydrologic projections developed from global climate models to evaluate the ways that projected climatic and hydrologic changes could impact water availability and management and water demands within the Sacramento, San Joaquin and Tulare Lake basins. The SSJIA analyzes potential impacts of climate change under a current trends projection of future urban growth considering the conversion of agricultural to urban land use and assuming the continuation of current crop types in the Central Valley. Finally, the SSJIA assesses risks to the eight major resource categories identified in the SWA by looking at a range of climate futures and attempting to book-end future uncertainties.

Sacramento River Temperature Task Group Annual Report of Activities October 1, 2013 through September 30, 2014

Delta Stewardship Council (Delta Council) | October 6th, 2014

Sacramento River Temperature Task Group Annual Report of Activities October 1, 2017 through September 30, 2018

Delta Stewardship Council (Delta Council) | November 21st, 2018

Salinas Valley Integrated Hydrologic and Reservoir Operations Models, Monterey and San Luis Obispo Counties, California

Monterey County Resources Agency (MCRA) | April 5th, 2025

To evaluate the challenging water management issues in the Salinas Valley, the U.S. Geological Survey, Monterey County Water Resource Agency, and the Salina

To evaluate the challenging water management issues in the Salinas Valley, the U.S. Geological Survey, Monterey County Water Resource Agency, and the Salinas Valley Basin Groundwater Sustainability Agency developed a comprehensive suite of models that represent the Salinas Valley Hydrogeologic system called the Salinas Valley System Model. The Salinas Valley Geologic Framework was developed to characterize the subsurface using various topographic and geologic data sources, including information on hydrogeologic units, their surfaces and extents, geologic structures, lithology, and elevations from borehole data and cross sections, as well as details on faults and existing models. The Salinas Valley Watershed Model simulates the entire Salinas River watershed. Monthly surface water inflows into the integrated hydrologic model domain were simulated using the Salinas Valley Watershed Model. The historical model uses historical climate data, water and land use data, and reservoir releases to simulate agricultural operations, including landscape water demands, diversions, and reclaimed wastewater. The operational model adds an embedded reservoir operations framework to the simulation of the historical model that allows specified operational rules to simulate reservoir releases and changes in reservoir storage. The operational model assumes current reservoir operations and constant land use, which differs from historical conditions. Thus, the operational model is a hypothetical baseline model that can be used by local water managers to evaluate and quantify potential benefits of water supply projects. Together, the geologic framework, watershed, historical, and operational models form a tool that can be used to simulate irrigated agriculture and associated reservoir operations of the integrated hydrologic system of the Salinas Valley.

Salinity Incursion and Water Resources, Appendix to Bulletin No. 76, Delta Water Facilities

California Department of Water Resources (DWR) | April 16th, 1962

Data and analyses contained in this appendix were utilized to determine the present and future quantity and quality of water supplies within the Delta and to determine

Data and analyses contained in this appendix were utilized to determine the present and future quantity and quality of water supplies within the Delta and to determine the conditions under which the State Water Facilities must operate within the Delta with the various facilities proposed in Bulletin No. 76 constructed therein. In general, the conditions imposed result from conservative assumptions of available water supply and Delta channel hydraulics.

San Francisco Bay: A Freshwater Starved Estuary

Bay Institute | September 1st, 2016

How Reducing Flows Harms the Ecosystems of San Francisco Bay and Coastal Waters The Bay Institute’s major new study, San Francisco Bay: The Freshwater – Starved Estu

How Reducing Flows Harms the Ecosystems of San Francisco Bay and Coastal Waters The Bay Institute’s major new study, San Francisco Bay: The Freshwater – Starved Estuary, documents how the ecological health of San Francisco Bay and the nearby ocean is at high risk because large-scale water diversion in the Bay’s watershed severely limits the amount of fresh water that reaches the Bay and alters the timing of that flow. Inflow to the Bay from its Central Valley watershed now averages less than half of what it would be without diversions; in some years just one-third of the runoff makes it to the Bay. The result is a nearly permanent drought for the Bay’s fish, wildlife, and their habitats. This radical alteration creates severe consequences for the Bay and marine ecosystems – and Bay Area residents pay the price. The study shows how unsustainable diversion of the Bay’s freshwater inflow: Dramatically cuts production of fish and shrimp that are the food source for marine mammals, like Orca Whales, and birds; Allows pollutants to accumulate to dangerous levels and encourages blooms of toxic algae; Reduces sediment supply to Bay Area wetlands and beaches; Makes it easier for undesirable non-native species to successfully invade the Bay Estuary. The San Francisco Bay Estuary is created by the mixing of fresh water from the Central Valley’s rivers with salt water from the Pacific Ocean. Dramatically reducing the inflow of fresh water generates cascading effects in the Bay’s watershed, the Bay itself, and coastal ocean waters. The report’s major findings include: On average, since 1975 more than half (53%) of runoff from the Central Valley watershed has been diverted, stored, or exported before it can reach the Bay – and in many years two-thirds or more of the Bay’s inflow is captured; As a result of intensive water diversions, the Bay experiences catastrophically dry years almost half the time (only one “supercritically dry” year occurred naturally between 1975-2014, but the Bay experienced nineteen supercritical years during that period); Numerous unrelated fish species – from sharks to salmon, from sturgeon to smelt – show strong positive correlations with Bay Inflow; many of these species are now endangered, and even commercially viable fisheries are in decline; Predators that feed on flow-dependent fish and shrimp are feeling the pinch – for example, dwindling supplies of Central Valley Chinook salmon may restrict the recovery of the local Orca whale population; Blooms of toxic “algae” (cyanobacteria) are becoming more frequent, and other pollutants are becoming more concentrated, as a result of reductions in freshwater flows from the Bay’s watershed; Bay Area beaches and tidal wetlands are deprived of sediment that was once transported by high river flows. The study reports that local businesses are likely to suffer from the Bay’s continued decline, including those related to commercial fishing and tourism. As our Bay, beaches, wetlands, and fish and wildlife populations deteriorate, the quality of life for many Bay Area residents will also be severely – and perhaps permanently – damaged. The study identifies four important approaches to improving Bay inflows: Update the State’s 21 year old water quality standards for the Bay Estuary to ensure adequate inflow Require all those who divert water destined for the Bay, not just a subset, to contribute their fair share of fresh water to support benefits enjoyed by all Californians Invest in local water supplies around the state including conservation, and recycling, that can generate millions of acre-feet of water and reduce reliance on water diverted from the Estuary and its watershed Coordinate management of flows with wetland and beach restoration to more effectively protect shorelines The study was prepared for the San Francisco Estuary Partnership, a coalition of resource agencies, non-profits, citizens, and scientists working to protect, restore, and enhance water quality and fish and wildlife habitat in and around the San Francisco Bay Delta Estuary, which also provided the majority of funding for the project.

San Joaquin River Restoration Settlement

Congressional Research Service (CRS) | November 9th, 2007

Historically, Central California’s San Joaquin River supported large Chinook salmon populations. Since the Bureau of Reclamation’s Friant Dam on the San Joaquin River

Historically, Central California’s San Joaquin River supported large Chinook salmon populations. Since the Bureau of Reclamation’s Friant Dam on the San Joaquin River became fully operational in the 1940s, much of the river’s water has been diverted for off-stream agricultural uses. As a result, approximately 60 miles of the river bed is dry in most years. Thus, the river no longer supports Chinook salmon populations in its upper reaches. In 1988, a coalition of conservation and fishing groups sued Reclamation (Natural Resources Defense Council v. Rodgers). A U.S. District Court judge has ruled that operation of Friant Dam violates state law because of its destruction of downstream fisheries. Faced with mounting legal fees, uncertainty, and the possibility of dramatic cuts to water diversions, parties negotiated a settlement instead of proceeding to trial. In September 2006, an agreement, commonly called the Settlement, was reached. It calls for new releases of water from Friant Dam to restore fisheries, as well as for efforts to mitigate reductions in off-stream deliveries lost to restoration flows. Congressional authorization and appropriations are required for full Settlement implementation. Legislation based on the Settlement (H.R. 4074, H.R. 24 and S. 27) is pending. Related bills have also been introduced. A key legislative issue is how to finance the Settlement, specifically how to resolve congressional pay-as-you-go (PAYGO) issues. Other challenges are how to achieve the Settlement’s dual goals of fisheries restoration and water management, and how to address concerns of stakeholders not party to the Settlement, without disrupting the negotiated agreement. The amount of water projected for restoration flows and the volume of reduced Friant water deliveries are related, but the relationship would not necessarily be one-for-one. Available estimates for total annual Friant water supplies (including both contract and temporary water) are, on average, 15% to 16% less under the Settlement than under current operations; but such estimates do not account for improvements in water management that might reduce the impact on water users. For three-quarters of water contractors, the reduction would represent a reduction in one of their available sources of water. The impacts of such reductions will vary by contractor depending on the firmness of existing surface water supplies and the reliability of groundwater supplies. How to offset the decrease and who would pay for investments in other water sources and improved efficiency has not been determined. Although the region may benefit from increased recreational expenditures and investment in river restoration activities under the Settlement, studies suggest its largest and mostly negative economic impact would be on the agriculture industry, at least in the short term. In addition, downsteam interests not party to the Settlement have been concerned about increased flooding, groundwater infiltration, and competition with existing federal financial commitments. Nearby communities fear harm to groundwater quantity and quality. Some of these concerns have been addressed in the legislation, but some remain. On the other hand, some communities and interests believe restoration will bring other benefits to the river, such as improved surface water quality in lower San Joaquin River reaches. Ultimate Settlement costs and benefits are very difficult to predict.

San Joaquin Valley Conveyance Study

California Department of Water Resources (DWR) | November 24th, 2025

This San Joaquin Valley Conveyance Study analyzes water conveyance needs in the San Joaquin Valley (Figure ES-1). The purpose of this study is to: •Describe the impa

This San Joaquin Valley Conveyance Study analyzes water conveyance needs in the San Joaquin Valley (Figure ES-1). The purpose of this study is to: •Describe the impacts of subsidence on San Joaquin Valley conveyance facilities. •Evaluate the need for improved or expanded conveyance facilities throughout the San Joaquin Valley.  

San Luis Obispo Coastkeeper v. Santa Maria Valley Water Conservation District

United States District Court, Central District of California | September 23rd, 2022