San Joaquin River

Nearly a Million Californians Lack Access to Safe Drinking Water

State of California | July 26th, 2022

Our audit of the State Water Board’s efforts to help provide Californians with safe drinking water highlighted the following: More than 370 of the State’s water

Our audit of the State Water Board’s efforts to help provide Californians with safe drinking water highlighted the following: More than 370 of the State’s water systems, serving nearly a million Californians, exceed the maximum contaminant levels for substances that are harmful to human health. More than 150 of these systems have been failing for at least five years. Hundreds of additional water systems are currently at risk of failing. The State Water Board has not prioritized the processing of water systems’ funding applications so that the systems can improve their water quality. Over the past five years, the average length of time for water systems to complete their applications and receive funding nearly doubled, from 17 months to 33 months. The State Water Board has not established performance goals or metrics related to its cumbersome application process. Although the State Water Board provides water systems with technical assistance to plan their improvements and apply for funds, it has not adequately monitored the performance of the technical assistance providers with which it contracts. The State Water Board needs to better ensure that its staff and its contracted providers do not duplicate each other’s outreach efforts.

Necessity for Comprehensive Adjudication of Water Rights on the Sacramento and San Joaquin Rivers in Aid of the Central Valley Project

U.S. Government Publishing Office (GPO) | November 30th, 1942

New Stone Water District Groundwater Sustainability Plan

New Stone Water District (NSWD) | December 23rd, 2019

This GSP covers about 4,200 acres in the northwestern area of the basin that is adjacent to the Chowchilla Bypass covering the New Stone Water District Groundwater Sustai

This GSP covers about 4,200 acres in the northwestern area of the basin that is adjacent to the Chowchilla Bypass covering the New Stone Water District Groundwater Sustainability Agency. The NSWD GSA is coterminous with the New Stone Water District (NSWD or District) boundary. The District is predominantly agriculture and consists of two landowners. The New Stone Water District Groundwater Sustainability Agency was created on December 22, 2016.

New Stone Water District GSA Groundwater Sustainability Plan

New Stone Water District (NSWD) | September 23rd, 2019

New Stone Water District Revised Groundwater Sustainability Plan

New Stone Water District (NSWD) | March 20th, 2023

Nitrate Implementation Measures Study (NIMS) Final Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | March 31st, 2016

This report summarizes the Nitrate Implementation Measures Study (NIMS) which addresses nitrate contamination in the groundwater basins underlying the floor of the Centra

This report summarizes the Nitrate Implementation Measures Study (NIMS) which addresses nitrate contamination in the groundwater basins underlying the floor of the Central Valley and appropriate implementation measures to mitigate nitrate contamination for these areas using a phased approach that includes providing safe drinking water, reducing or eliminating impacts to drinking water sources and implementing managed restoration activities where needed to restore beneficial uses in groundwater. These implementation measures will be incorporated into the SNMP. The findings from both the SSALTS and the NIMS will be used to guide discussions regarding the need for changes to the existing Basin Plan to facilitate salt disposal and mitigation measures for nitrate in a manner that is most beneficial to the region covered by the SNMP. 

Nitrogen Fertilizer Loading to Groundwater in the Central Valley

University of California, Davis (UC Davis) | October 31st, 2017

Nitrate‐nitrogen is the most common pollutant found in the Central Valley aquifer system of California. This project provides a long‐term assessment of past and curr

Nitrate‐nitrogen is the most common pollutant found in the Central Valley aquifer system of California. This project provides a long‐term assessment of past and current potential nitrogen loading to groundwater on irrigated and natural lands across the entire Central Valley of California using a nitrogen mass balance approach; assesses the long‐term implications for groundwater quality in the Central Valley (Sacramento Valley, San Joaquin Valley, and Tulare Lake Basin); evaluates potential best management practices to reduce groundwater nitrogen loading from irrigated lands; and provides a planning tool to better understand local and regional groundwater quality response to specific best management practices and policy/regulatory actions. The project complements other work to assess the vulnerability of Central Valley groundwater to nitrate contamination, sources of nitrate in groundwater, and how to reduce source loading.

No-tillage and high-residue practices reduce soil water evaporation

California Agriculture (UCANR) | April 1st, 2012

Reducing tillage and maintaining crop residues on the soil surface could improve the water use efficiency of California crop production. In two field studies co

Reducing tillage and maintaining crop residues on the soil surface could improve the water use efficiency of California crop production. In two field studies comparing no-tillage with standard tillage operations (following wheat silage harvest and before corn seeding), we estimated that 0.89 and 0.97 inches more water was retained in the no-tillage soil than in the tilled soil. In three field studies on residue coverage, we recorded that about 0.56, 0.58 and 0.42 inches more water was retained in residue-covered soil than in bare soil following 6 to 7 days of overhead sprinkler irrigation. Assuming a seasonal crop evapotranspiration demand of 30 inches, coupling no-tillage with practices preserving high residues could reduce summer soil evaporative losses by about 4 inches (13%). However, practical factors, including the need for different equipment and management approaches, will need to be considered before adopting these practices.

North American diadromous fishes: Drivers of decline and potential for recovery in the Anthropocene

American Association for the Advancement of Science (AAAS) | January 28th, 2022

Diadromous fishes migrate between freshwater and marine habitats to complete their life cycle, a complexity that makes them vulnerable to the adverse effects of current

Diadromous fishes migrate between freshwater and marine habitats to complete their life cycle, a complexity that makes them vulnerable to the adverse effects of current and past human activities on land and in the oceans. Many North American species are critically endangered, and entire populations have been lost. Major factors driving declines include overfishing, pollution, water withdrawals, aquaculture, non-native species, habitat degradation, over-zealous application of hatcheries designed to mitigate effects of other factors, and effects of climate change. Perhaps, the most broadly tractable and effective factors affecting diadromous fishes are removals of the dams that prevent or hinder their migrations, alter their environment, and often favor non-native biotic communities. Future survival of many diadromous fish populations may depend on this.

North Delta Water Management Program

California Department of Water Resources (DWR) | March 1st, 1988

Water management issues surrounding the Sacramento-San Joaquin Delta continue to challenge water resource planners in California. Many agree there are problems and urge

Water management issues surrounding the Sacramento-San Joaquin Delta continue to challenge water resource planners in California. Many agree there are problems and urge that they be corrected, but a consensus on how best to solve them has not yet been reached. Problems include frequent flooding due to unstable levees and constricted channels, flow patterns that are unfavorable for fish and water quality, and water level and circulation patterns that hinder irrigation. During the last several years, various water resources problems have been corrected through application of the public environmental documentation and regulatory permit process. This process has also shown the importance of Federal permit regulations in governing projects in the Delta estuary. To facilitate planning, the estuary has been divided into three study areas for evaluation of problems and needs unique to each area -- North, South, and West. This report discusses concepts for a North Delta Water Management Program. The long-term planning and environmental documentation process will includeother reports and will take about three years to complete. Planning flexibility afforded by the environmental documentation and regulatory permit process is expected to allow many of the concerns surrounding Delta water management to be resolved.