San Joaquin Valley – Westside
Statistics
- Basin Name
- San Joaquin Valley – Westside
- Basin Number
- 5-022.09
- SGMA Basin Priority
- High
- Critically Overdrafted
- Yes
- Hydrologic Region Name
- Tulare Lake
- Counties
- Fresno, Kings
Basin Notes
2003: Bulletin 118 basin description
2014: CASGEM basin prioritization – high
2016: Basin boundary modifications approved with Kings 5-022.08, Madera 5-022.06, Delta-Mendota 5-022.07 and Tracy 5-022.15 subbasins An amended, approved modification was also made with the border of Pleasant Valley subbasin 5-022.09
Revised basin boundary description
2018: Draft priority : High. Groundwater level and subsidence comments:
- CRITICAL OVERDRAFT. 1) CASGEM/WDL/GWIDS: No data or data insufficent to determine GWL status. Source: DWR 2) The canal, now considered the middle section of the California Aqueduct, passes through three major subsidence bowls: 1) southwest of Mendota, 2) near the town of Cantua Creek, and 3) near the town of Huron (Ireland and others, 1984). Because subsidence due to groundwater extraction had adversely affected the earlier-built Delta-Mendota Canal, designers incorporated as much as 10 feet of extra freeboard into the San Luis Canal, adding $30.7 million (2013 dollars) to construction costs. Sources: Land Subsidence from Groundwater Use in California, James W. Borchers, Michael Carpenter, Luhdorff & Scalmanini, California Water Foundation, April, 2014 2) Current Land Subsidence in the San Joaquin Valley, USGS; 3) Progress Report: Subsidence in the Central Valley, California, Jet Propulsion Laboratory, California Institute of Technology, NASA 2015-16
Final Basin Prioritization: High.
2020:
- January 23 – Westlands Water District GSA submitted a Groundwater Sustainability Plan (GSP) to the Department of Water Resources (DWR)
2022:
- January 21 — DWR found the GSP incomplete and gave the GSA 180 days to address deficiencies.
- July 18 — GSA resubmits an amended GSP
2023: October 26 – DWR approved the GSP
2024: 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
The State Water Project Delivery Capability Report 2023 Addendum - Impacts of Subsidence
California Department of Water Resources (DWR) | May 7th, 2025
The purpose of this addendum is to show how ongoing subsidence effects on the California Aqueduct will impact operation of the State Water Project (SWP). The addendum pro
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
Drought, water management, and agricultural livelihoods: Understanding human-ecological system management and livelihood strategies of farmer’s in rural California
Elsevier | July 11th, 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
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
CV-SALTS Groundwater Sustainability Plan Data Collection - Pilot Study Results
Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | February 1st, 2024
The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize relevan
Statement of Findings regarding the Approval of the San Joaquin Valley – Westside Subbasin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | October 26th, 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
Westside Subbasin Groundwater Sustainability Plan (Clarified and Amended GSP)
Westlands Water District | July 18th, 2022
Due to size, this file has been divided into 11 parts. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11
Statement of Findings regarding the Determination of Incomplete Status of the San Joaquin Valley - Westside Subbasin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | January 21st, 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?
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
Westside Subbasin Groundwater Sustainability Plan
Westlands Water District | January 23rd, 2020
Report of Waste Discharge and Technical Report
Westlands Water District | July 10th, 2019
This Technical Report is in support of a Report of Waste Discharge (ROWD) for an agricultural aquifer storage and recovery (Ag-ASR) program for Westlands Water District
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