San Gabriel Valley
Statistics
- Basin Name
- San Gabriel Valley
- Basin Number
- 4-013
- SGMA Basin Priority
- Very Low
- Critically Overdrafted
- No
- Hydrologic Region Name
- South Coast
- Counties
- Los Angeles
Basin Notes
1973-present: History of the basin adjudication, San Gabriel Valley Watermaster
1993: San Gabriel Basin Water Quality Authority formed by legislature in response to groundwater contamination
2003: Bulletin 118 basin description
2005: San Gabriel River Corridor Master Plan hydrology chapter, LA County Department of Public Works
2006: June – San Gabriel River Corridor Master Plan, LA County Department of Public Works
2012: June 21 – Upper San Gabriel Valley Municipal Water District v. City of Alhambra et al
2014: CASGEM basin priority – high. Comment – Superfund sites in basin.
2016: May – San Gabriel Valley Groundwater Basin Salt and Nutrient Management Plan
An Evaluation of California’s Adjudicated Groundwater Basins, Langridge et al, (UC Davis) 2016
2017: August 30 – Contaminated ground water in San Gabriel Valley gets $250 million boost, extending cleanup until 2027, San Gabriel Valley Tribune
2018: Draft basin prioritization – Very Low. Comments:
- 1) CASGEM/WDL/GWIDS: Long term hydrographs more or less stable. Source: DWR
- 2) Water Master Annual report hydrograph for key well shows a decline of about 50 feet since 1989. Source: Main San Gabriel Basin Watermaster Annual Report 2015-2016
2017-18 Main San Gabriel Basin Watermaster Annual Report; previous yearly reports Basin 97.01 adjudicated. Web page: Main San Gabriel Basin Watermaster
2018 Final Basin Prioritization: changed to Very Low
2021: May – San Gabriel Valley Superfund Sites Progress Update – US Environmental Protection Agency (USEPA)
2022: September 15 — Fourth Five Year Review Report for the San Gabriel Valley Area 2 Superfund Site, Los Angeles, California
2023: April 30 – 2022 Annual Performance Evaluation Report – Volume 1 – Baldwin Park Operable Unit Of The San Gabriel Valley Superfund Sites Los Angeles County, California, U.S. Environmental Protection Agency
2024: January 31 – DWR acknowledges a GSP submitted for unadjudicated areas of the basin
2025: Groundwater Sustainability Plan for unadjudicated areas deemed incomplete by DWR
At-A-Glance
California Water Library Documents About This Basin
Statement of Findings Regarding the Determination of Incomplete Status of the San Gabriel Valley Basin Groundwater Sustainability Plan
California Department of Water Resources (DWR) | April 28th, 2025
The Plan does not demonstrate that areas within the San Gabriel Valley Basin that are not covered by an adjudication and are outside the area covered by the Plan (i.e., t
Depth-dependent seismic sensing of groundwater recovery from the atmospheric-river storms of 2023
American Association for the Advancement of Science (AAAS) | February 13th, 2025
In early 2023, a series of intense atmospheric-river storms eased California’s historic drought, yet the spatiotemporal extent of groundwater recovery remains poorly un
Advancing Stormwater Capture for Greener Schools in Los Angeles
Pacific Institute | August 15th, 2024
In communities across the United States, schools provide an enriching and safe environment for children to learn and grow. Yet urban schools, particularly those serving
Evidence for faulting and fluid-driven earthquake processes from seismic attenuation variations beneath metropolitan Los Angeles
Nature Portfolio (Springer Nature) | July 30th, 2024
Los Angeles County’s Climate Cost Challenge
Center for Climate Integrity | April 2nd, 2024
Within the first two months of 2024, the City of Los Angeles had already exceeded its average annual rainfall, receiving nearly 15 inches of rain in back-to-back deluges.
Los Angeles County Water Plan 2023
Los Angeles County Department of Public Works (LACDPW) | December 5th, 2023
Over 200 agencies in Los Angeles County manage a complex network of water systems to meet the needs of our communities and environment. To achieve sustainability, resilie
Fourth Five Year Review Report for the San Gabriel Valley Area 2 Superfund Site, Los Angeles, California
U.S. Environmental Protection Agency (EPA) | September 15th, 2022
This is the fourth Five-Year Review of the San Gabriel Valley Area 2 (Site) located in the San Gabriel Valley in Los Angeles County, California. The purpose of this Five-
Equity in Stormwater Investments: Measuring Community Engagement and Disadvantaged Community Benefits for Equitable Impact in the Safe Clean Water Program
Publisher not available | August 4th, 2022
The Safe, Clean Water Program (SCWP) reflects the will of the voters of Los Angeles County, who approved Measure W in 2018 by close to 70%. The ballot measure established
Groundwater Sustainability Plan for the Spadra Basin
Spadra Basin Groundwater Sustainability Agency (Spadra Basin) | January 17th, 2022
The Spadra Basin is a small, non‐adjudicated subbasin of the San Gabriel Valley Basin (Basin 4-013 as defined by DWR). The DWR designated the San Gabriel Valley Basin a
San Gabriel Valley Superfund Sites Progress Updates
U.S. Environmental Protection Agency (EPA) | May 31st, 2021
Historical Ecology of the Los Angeles River Watershed and Environs, Infrastructure for a Comprehensive Analysis
University of Southern California (USC) | June 15th, 2020
Achievements in Conservation, Recycling, and Groundwater Recharge Covering Fiscal Year July 2018-June 2019
Metropolitan Water District of Southern California (MWD) | March 1st, 2020
One Water LA 2040 Plan
City of Los Angeles | April 30th, 2018
The purpose of the One Water LA 2040 Plan (Plan) is to increase sustainable water management for the City of Los Angeles (City). The City launched One Water LA with two p
Estimating Spatially and Temporally Varying Recharge and Runoff from Precipitation and Urban Irrigation in the Los Angeles Basin, California
U.S. Geological Survey (USGS) | October 6th, 2016
A daily precipitation-runoff model, referred to as the Los Angeles Basin watershed model (LABWM), was used to estimate recharge and runoff for a 5,047 square kilometer st
Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century
Environmental Research Letters (IOP) | September 21st, 2016
The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of C
San Gabriel Valley Groundwater Basin Salt And Nutrient Management Plan
Publisher not available | May 31st, 2016
Upper San Gabriel Valley Municipal Water District v. City of Alhambra et al
Superior Court of California, County of Los Angeles | June 21st, 2012
Background note from An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, (UC Davis) 2016 The Main San Gabriel Basin is one of the larges
Groundwater Quality in the San Fernando–San Gabriel Groundwater Basins, California
U.S. Geological Survey (USGS) | March 31st, 2012
Final Groundwater Assessment Study: A Status Report on the Use of Groundwater in the Service Area of the Metropolitan Water District of Southern California
Metropolitan Water District of Southern California (MWD) | September 3rd, 2007
Los Angeles County Department of Public Works Hydrology Manual
Los Angeles County Department of Public Works (LACDPW) | January 30th, 2006
This manual establishes the Los Angeles County Department of Public Works' hydrologic design procedures and serves as a reference and training guide. This manual contains