San Joaquin Valley – Chowchilla
- Basin Name
- San Joaquin Valley – Chowchilla
- Basin Number
- SGMA Basin Priority
- Critically Overdrafted
- Subject to SGMA
- DWR Region & POC
South Central Region Office
- Number of Wells
- Hydrologic Region Name
- San Joaquin River
Located in California’s San Joaquin River hydrologic region, the San Joaquin Valley – Chowchilla is 145,574.30 acres in size. This High priority basin is home to an estimated 15,100 people (2010 value), which have been at a rate of 29. San Joaquin Valley – Chowchilla is a(n) basin with approximately 1489 wells, of which approximately 16 are water supply wells. Groundwater accounts for approximately 95.58 percent of the basin’s water supply.
2014: CASGEM basin prioritization – high
2016: Basin boundary modification with the Madera subbasin
2018: Draft basin priority – high. Comments on groundwater levels and subsidence:
- CRITICAL OVERDRAFT 2016. Source: DWR 1) CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR
- 2) Groundwater levels in the Chowchilla Groundwater Basin have declined an average of 40 ft from 1970 through 2000. Limited information is available on groundwater trends for the Chowchilla Groundwater Basin after the year 2000.
- Sources : 1) Current land subsidence in the San Joaquin Valley, USGS; 2) 2014 – Land Subsidence from Groundwater Use in California, California Water Foundation / James W. Borchers / Michael Carpenter, Luhdorff & Salmanini, April 2014; 3) Progress Report: Subsidence in the Central Valley, California, Jet Propulsion Laboratory, California Institute of Technology, NASA 2015-16; 4) San Joaquin River Restoration Program / US Bureau of Reclamation monitoring
Groundwater Quality in the Shallow Aquifers of the Madera– Chowchilla and Kings Subbasins, San Joaquin Valley, California, U.S. Geological Survey, January 2018
2019: Basin boundary modification. Per DWR: It “revises the easterly portion of the Chowchilla Merced subbasins boundary to follow the Madera- Merced County line.” Phase 2 draft priority remains high.