San Joaquin River

Contributions of Climate Change and ENSO Variability to Future Precipitation Extremes Over California

American Geophysical Union (AGU) | June 14th, 2023

Coordinated Long-Term Operation of the Central Valley Project and State Water Project, Final Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | November 30th, 2015

Costs of Ecosystem Management Actions for the Sacramento-San Joaquin Delta

Public Policy Institute of California (PPIC) | April 22nd, 2013

California is at a critical juncture on policy for the Sacramento–San Joaquin Delta. This report summarizes the results of a wide-ranging study of cost-effective wa

California is at a critical juncture on policy for the Sacramento–San Joaquin Delta. This report summarizes the results of a wide-ranging study of cost-effective ways to improve the health of the Delta ecosystem. It highlights the need for science-based, integrated management of the many sources of ecosystem stress. The report also recommends improvements to the highly fragmented system of oversight that now involves dozens of federal, state, and local agencies. Several companion reports contain related findings: Aquatic Ecosystem Stressors in the Sacramento–San Joaquin Delta (Mount et al. 2012) summarizes the science of Delta ecosystem stressors for a policymaking audience. Integrated Management of Delta Stressors: Institutional and Legal Options (Gray et al. 2013) lays out proposals for institutional reform of science, management, and regulation. Scientist and Stakeholder Views on the Delta Ecosystem (Hanak et al. 2013) presents detailed results of the two surveys conducted by the report’s authors. Stress Relief: Prescriptions for a Healthier Delta Ecosystem (Hanak et al. 2013) summarizes the overall research project and the recommendations it generated. Where the Wild Things Aren’t: Making the Delta a Better Place for Native Species (Moyle et al. 2012) outlines a realistic long-term vision for achieving a healthier ecosystem.

Counties Wresting Control: Local Responses to California's Statewide Water Market

University of Denver Water Law Review (UDWLR) | January 1st, 2003

Cover cropping and no-tillage improve soil health in an arid irrigated cropping system in California’s San Joaquin Valley, USA

Soil and Tillage Research (Elsevier) | January 3rd, 2017

The concept of soil health has attracted considerable attention during the past two decades, but few studies have focused on the effects on soil health of long-term soil

The concept of soil health has attracted considerable attention during the past two decades, but few studies have focused on the effects on soil health of long-term soil management in arid irrigated environments. We investigated the effects of cover cropping and no-till management on soil physical and chemical properties during a 15-year experiment in California’s San Joaquin Valley (SJV) USA. Our objective was to determine if soil health could be improved by these practices in an annual crop rotation. The impact of long-term no-tillage (NT) and cover cropping (CC) practices, alone and in combination, was measured and compared with standard tillage (ST) with and without cover crops (NO) in irrigated row crops after 15 years of management. Soil aggregation, rates of water infiltration, content of carbon, nitrogen, water extractable organic carbon (WEOC) and organic nitrogen (WEON), residue cover, and biological activity were all increased by NT and CC practices relative to STNO. However, effects varied by depth with NT increasing soil bulk density by 12% in the 0–15 cm depth and 10% in the 15–30 cm depth. Higher levels of WEOC were found in the CC surface (0–5 cm) depth in both spring and fall samplings in 2014. Surface layer (0–15 cm) WEON was higher in the CC systems for both samplings. Tillage did not affect WEON in the spring, but WEON was increased in the NT surface soil layer in the fall. Sampling depth, CC, and tillage affected 1-day soil respiration and a soil health index assessment, however the effects were seasonal, with higher levels found in the fall sampling than in the spring. Both respiration and the soil health index were increased by CC with higher levels found in the 0–5 cm depth than in the 5–15 and 15–30 cm depths. Results indicated that adoption of NT and CC in arid, irrigated cropping systems could benefit soil health by improving chemical, physical, and biological indicators of soil functions while maintaining similar crop yields as the ST system.

Critical Aquifer Overdraft Accelerates Degradation of Groundwater Quality in California's Central Valley During Drought

American Geophysical Union (AGU) | September 1st, 2021

It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood. 

It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood. This study examined 30 yr of data from California's Central Valley to find dramatic groundwater-level declines during drought were associated with worsening groundwater quality. This likely happens because increased pumping during drought can draw shallow, contaminated groundwater to depths commonly tapped by public drinking water wells. This is the first study of its kind to show direct linkages between drought and groundwater quality at such a broad spatial scale

Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

University of California, Davis (UC Davis) | July 1st, 2005

Cultivating climate resilience in California agriculture: Adaptations to an increasingly volatile water future

National Academy of Sciences (NAS) | July 29th, 2024

CV SALTS Prioritization & Optimization Study Year 1 Progress Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | March 24th, 2023

CV-SALTS Central Valley Region Salt & Nitrate Control Program Surveillance and Monitoring Program

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | February 3rd, 2023

The prioritized Nitrate Control Program and phased Salt Control Program are designed to address both legacy and ongoing salt and nitrate accumulation issues in groundwate

The prioritized Nitrate Control Program and phased Salt Control Program are designed to address both legacy and ongoing salt and nitrate accumulation issues in groundwater and salinity concerns in surface waters. However, the primary focus of early actions being implemented under the Nitrate Control Program (i.e., the first ten years) is on groundwater quality and in particular nitrate impacts to drinking water supplies. The overarching management goals and priorities of the SNCP are to: Ensure safe drinking water supply; Reduce salt and nitrate loading so that ongoing discharges neither threaten to degrade high quality waters absent appropriate findings by the Central Valley Board, nor cause or contribute to exceedances of water quality objectives; and Implement long-term, managed restoration of impaired waterbodies.