San Joaquin Valley – Chowchilla
Statistics
- Basin Name
- San Joaquin Valley – Chowchilla
- Basin Number
- 5-022.05
- SGMA Basin Priority
- High
- Critically Overdrafted
- Yes
- Hydrologic Region Name
- San Joaquin River
- Counties
- Madera
Basin Notes
2003: Bulletin 118 basin description
2018: Priority – High. CRITICAL OVERDRAFT
2020: January – Chowchilla Subbasin Sustainabile Groundwater Management Act Groundwater Sustainability Plan published
2021: November – GSP deemed insufficient
2022: July 27 – Chowchilla plan managers submit a revised GSP
2023: March 2 – DWR deems the revised GSP inadequate
2025: April 1 – Water Board defers putting basin on probation and refers it back to DWR to evolve its GSPs
At-A-Glance

California Water Library Documents About This Basin
Chowchilla Subbasin Staff Assessment
California State Water Resources Control Board (SWRCB) | April 1st, 2025
The state intervention process for the Chowchilla Subbasin was triggered in March 2023 when DWR determined the subbasin’s 2022 GSP was inadequate and identified multipl
Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan (3rd Revision)
Madera County | January 3rd, 2025
In 2024-2025, the GSAs revised the Subbasin GSP to: Amend the Domestic Well Mitigation Program Refine the Groundwater Level Representative Monitoring Sites (RMS
Quantification of record-breaking subsidence in California’s San Joaquin Valley
Nature Portfolio (Springer Nature) | November 19th, 2024
Replenishing Groundwater in the San Joaquin Valley: 2024 Update
Public Policy Institute of California (PPIC) | June 6th, 2024
Strategies to replenish groundwater basins—long used in some areas of the San Joaquin Valley—have increasingly come into focus as the region seeks to bring its overd
Status of Water Quality in Groundwater Resources Used for Drinking-Water Supply in the Southeastern San Joaquin Valley, 2013–15: California GAMA Priority Basin Project
U.S. Geological Survey (USGS) | April 25th, 2024
The California Groundwater Ambient Monitoring and Assessment Program Priority Basin Project (GAMA-PBP) investigated water quality of groundwater resources used for drinki
Groundwater sustainability and land subsidence in California’s Central Valley
Water (MDPI) | April 22nd, 2024
The Central Valley of California is one of the most prolific agricultural regions in the world. Agriculture is reliant on the conjunctive use of surface-water and groundw
Thousands of domestic and public supply wells face failure despite groundwater sustainability reform in California’s Central Valley
Nature Portfolio (Springer Nature) | September 8th, 2023
LandFlex Program’s Guidelines
California Department of Water Resources (DWR) | December 8th, 2022
LandFlex is a program that will provide $25 million in block grants to local government agencies to grant to farmers who limit agricultural water use. Local government ag
Modeling the dynamic penetration depth of post-1950s water in unconfined aquifers using environmental tracers: Central Valley, California
Journal of Hydrology (Elsevier) | December 5th, 2022
The penetration depth of post-1950s recharge (D-1950) in aquifers is a marker that is frequently used to identify groundwater that is susceptible to anthropogenic contami
Subsurface water flux in California's Central Valley and its source watershed from space geodesy
American Geophysical Union (AGU) | September 29th, 2022
We combine measurements from Global Positioning System positioning and Gravity Recovery and Climate Experiment gravity to infer change in water components in Central Vall
Chowchilla Subbasin Sustainable Groundwater Management Act (SGMA) Groundwater Sustainability Plan (Revised)
Chowchilla Subbasin GSP Advisory Committee | July 27th, 2022
Due to file size, this document has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Par
Statement of Findings regarding the Determination of Incomplete Status of the Chowchilla Subbasin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | January 28th, 2022
The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP or Plan) conforms to specific requirements
Post-Drought Groundwater Storage Recovery in California's Central Valley
American Geophysical Union (AGU) | October 5th, 2021
California's Central Valley has experienced chronic groundwater depletion over the past few decades, the rate of which was amplified by droughts in 2007–2009 and 2012?
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.
Identification of Bacteria in Groundwater Used for Domestic Supply in the Southeast San Joaquin Valley, California, 2014
U.S. Geological Survey (USGS) | June 22nd, 2021
Groundwater is an important source of drinking water in California. Water-borne diseases caused by microbial contamination are a growing concern. The MI test, a membrane
Groundwater development leads to decreasing arsenic concentrations in the San Joaquin Valley, California
Science of the Total Environment (Elsevier) | January 18th, 2021
In the San Joaquin Valley (SJV), California, about 10% of drinking water wells since 2010 had arsenic concentrations above the U.S. maximum contaminant level of 10μg/L.
Base of fresh water, groundwater salinity, and well distribution across California
National Academy of Sciences (NAS) | December 9th, 2020
The depth at which groundwaters transition from fresh to more saline—the “base of fresh water”—is frequently used to determine the stringency and types of measure
Divergent effects of climate change on future groundwater availability in key mid-latitude aquifers
Nature Portfolio (Springer Nature) | July 24th, 2020
Groundwater provides critical freshwater supply, particularly in dry regions where surface water availability is limited. Climate change impacts on GWS (groundwater stora
Groundwater Management and Safe Drinking Water in the San Joaquin Valley
Water Foundation | June 2nd, 2020
Domestic well vulnerability to drought duration and unsustainable groundwater management in California's Central Valley
Environmental Research Letters (IOP) | March 18th, 2020
Millions of Californians access drinking water via domestic wells, which are vulnerable to drought and unsustainable groundwater management. Groundwater overdraft and th