San Joaquin Valley – Turlock
Statistics
- Basin Name
- San Joaquin Valley – Turlock
- Basin Number
- 5-022.03
- SGMA Basin Priority
- High
- Critically Overdrafted
- No
- Hydrologic Region Name
- San Joaquin River
- Counties
- Merced, Stanislaus
- Adjacent Basins
Basin Notes
2003: Bulletin 118 basin description
2008: Turlock Groundwater Basin Draft Groundwater Management Plan
2014: CASGEM prioritization. High
2018: Draft basin prioritization. High. Comment: CASGEM/WDL/GWIDS: Longterm hydrographs show groundwater level decline. Source: DWR 2) Pumping depressions and groundwater level decline stated in GWMP
Final Basin Prioritization: High.
2022: January 28 – GSP submitted to DWR
2024: January 18 – GSP deemed incomplete by DWR
July 12 – Revised GSP submitted to DWR
July 18 – Comment period opened by DWR until 9/16
July 31 – US Fish and Wildlife Service releases the 15-year plan, the San Luis National Wildlife Refuge Complex Final Comprehensive Conservation Plan and Environmental Assessment
At-A-Glance

California Water Library Documents About This Basin
2024 Annual Multibenefit Land Repurposing Program Report
California Department of Conservation (CDoC) | May 29th, 2025
The Multibenefit Land Repurposing Program (MLRP) increases regional capacity for repurposing irrigated agricultural land to uses that reduce reliance on groundwater while
Statement of Findings Regarding the Approval of the San Joaquin Valley – Turlock Subbasin 2024 Groundwater Sustainability Plan
California Department of Water Resources (DWR) | February 27th, 2025
CV-SALTS Preliminary Management Zone Proposal for Priority 2 Management Zones
Valley Water Collaborative | December 30th, 2024
The Nitrate Control Program is designed to achieve the following three management goals in the Central Valley Region: Goal 1 – Ensure a safe drinking water
Quantification of record-breaking subsidence in California’s San Joaquin Valley
Nature Portfolio (Springer Nature) | November 19th, 2024
San Luis National Wildlife Refuge Complex Final Comprehensive Conservation Plan and Environmental Assessment
U.S. Fish and Wildlife Service (FWS) | July 31st, 2024
This Comprehensive Conservation Plan (CCP) will guide the management of the Merced National Wildlife Refuge (NWR), San Luis NWR and Grasslands Wildlife Management Area (W
Turlock Subbasin Groundwater Sustainability Plan (Revised)
West and East Turlock Subbasin Groundwater Sustainability Agencies | July 12th, 2024
The Turlock GSAs submitted the first version of the Turlock GSP to the Department of Water Resources (DWR) in January 2022. DWR determined the GSP to be incomplete in J
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
Multibenefit Land Repurposing Program Annual Report 2023
California Department of Conservation (CDoC) | April 9th, 2024
The Multibenefit Land Repurposing Program (MLRP) increases regional capacity for repurposing irrigated agricultural land to uses that reduce reliance on groundwat
Statement of Findings Regarding the Determination of Incomplete Status of the San Joaquin Valley - Turlock Subbasin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | January 18th, 2024
The Department of Water Resources (Department) is required to evaluate whether a submitted groundwater sustainability plan (GSP or Plan) conforms to specific requirements
CV-SALTS Turlock Management Zone Implementation Plan
Valley Water Collaborative | September 5th, 2023
The Central Valley Regional Water Quality Control Board (Central Valley Water Board) adopted amendments to the Water Quality Control Plan for the Sacramento River and San
Quality of Groundwater Used for Domestic Supply in the Modesto, Turlock, and Merced Subbasins of the San Joaquin Valley, California
U.S. Geological Survey (USGS) | January 6th, 2023
More than 2 million Californians rely on groundwater from privately owned domestic wells for drinking-water supply. This report summarizes a water-quality survey of domes
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
Turlock Subbasin Groundwater Sustainability Plan
West and East Turlock Subbasin Groundwater Sustainability Agencies | January 6th, 2022
The Turlock Subbasin Groundwater Sustainability Plan (GSP) was adopted January 6, 2022, and covers the Turlock Subbasin (5-22.03), which has been designated a high-priori
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.
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
A hybrid machine learning model to predict and visualize nitrate concentration throughout the Central Valley aquifer, California, USA
Science of the Total Environment (Elsevier) | June 9th, 2017
Intense demand for water in the Central Valley of California and related increases in groundwater nitrate concentration threaten the sustainability of the groundwater res
Simulations of Ground-Water Flow and Particle Pathline Analysis in the Zone of Contribution of a Public-Supply Well in Modesto, Eastern San Joaquin Valley, California
U.S. Geological Survey (USGS) | July 1st, 2008