San Joaquin Valley – Turlock

Statistics

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

View Document Download

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

View Document Download

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

View Document Download

Quantification of record-breaking subsidence in California’s San Joaquin Valley

Nature Portfolio (Springer Nature) | November 19th, 2024

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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?

View Document Download

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. 

View Document Download

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.

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

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

View Document Download

GSA Information