California Water Science Center


Filter Total Items: 92
Date published: September 28, 2021
Status: Completed

Los Angeles Coastal Plain Groundwater-flow Model

The Los Angeles Coastal Plain Groundwater-flow Model (LACPGM) is a tool to help water managers better understand groundwater flow and seawater intrusion in the Los Angeles coastal plain basins. It is the culmination of years of data collection and studies in the area and builds on our understanding of the area’s geology and hydrology obtained through the geologic and groundwater flow models....

Contacts: Scott Paulinski
Date published: August 11, 2021
Status: Active

Investigation of Groundwater and Surface Water Interactions in Support of Ecosystem Management at San Sebastian Marsh, California

To help the U.S. Bureau of Land Management determine the long-term sustainability of the San Sebastian Marsh, and its critical role for the survival of the endangered desert pupfish (Cyprinodon macularius), the USGS is evaluating the potential interactions and relation between groundwater and surface water at the San Sebastian Marsh.

Contacts: Gregory Mendez
Date published: June 30, 2020
Status: Active

Hydrogeological Evaluation of the Edwards Air Force Base Air Force Research Laboratory Area, Antelope Valley, California

In cooperation with Air Force Civil Engineer Center (AFCEC), the U.S. Geological Survey (USGS) is evaluating the hydrogeology of the Air Force Research Laboratory (AFRL) and Site 25 areas of Edwards Air Force Base (EAFB) and the adjacent North-Muroc groundwater subbasin to help determine regional groundwater movement and the possible long-term movement and pathways of contaminated...

Contacts: Nicole C Fenton
Date published: April 8, 2020
Status: Active

Evaluation of Groundwater Resources in the Adelaida Area of San Luis Obispo County, California

Stakeholders in San Luis Obispo County are concerned that the increased demand for water use has, and will continue to, affect groundwater levels and availability in the Adelaida area. To address stakeholder concerns, the County of San Luis Obispo Board of Supervisors has asked the USGS to conduct a comprehensive evaluation of groundwater resources of the Adelaida area. 

Date published: April 7, 2020
Status: Completed

MODFLOW One-Water Hydrologic Flow Model—Conjunctive Use Simulation Software (MF-OWHM)

The MODLFOW One-Water Hydrologic Flow Model (MF-OWHM) Conjunctive Use Simulation Software (Boyce and others, 2020Hanson and others, 2014) is a MODFLOW-2005-based integrated hydrologic flow model (IHM) that is the most complete...

Date published: February 18, 2020
Status: Active

Evaluation of groundwater resources of the Anza-Terwilliger area, Anza, California

Groundwater is the sole source for water use to the rural community and two Native American tribes in the Cahuilla Valley and Terwilliger Valley groundwater basins, which are located approximately 35 miles southwest of Palm Springs, California. The characteristics and sustainable yield of the basins are not well understood and are threatened by increasing water use and potential changes in...

Date published: June 12, 2019
Status: Active

Land Subsidence in California

Extensive groundwater withdrawals from aquifer systems have caused land subsidence in many California basins. Land subsidence can cause infrastructure damage, not only to buildings and roads but also to water conveyence systems. Groundwater-level and land-subsidence monitoring provide the information needed to guide mitigation efforts and management of future effects.

Date published: May 16, 2019
Status: Active

San Diego Hydrogeology

This is the first comprehensive geologic and hydrologic study for the San Diego area. This study will provide the integrated hydrogeologic knowledge necessary in this important and highly visible area of the United States and will serve as a role model for similar coastal settings throughout the world that have modest rainfall and small aquifers. Locally, results will help...

Contacts: Wesley Danskin
Date published: May 2, 2019
Status: Active

Groundwater Ambient Monitoring & Assessment (GAMA)

The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the...

Contacts: Miranda Fram
Date published: April 26, 2019
Status: Active

Occurrence of natural and anthropogenic hexavalent chromium (Cr VI) in groundwater near a mapped plume, Hinkley, CA

Between 1952 and 1964, cooling water was treated with a compound containing chromium to prevent corrosion within the Pacific Gas and Electric Company (PG&E) Hinkley Compressor Station. This water was discharged to unlined ponds, resulting in contamination of soil and groundwater within the underlying alluvial aquifer. The purpose of this study is to evaluate the occurrence of natural and...

Contacts: John Izbicki
Date published: April 26, 2019
Status: Active

Regional Groundwater Availability Study of the California Coastal Basins

This study seeks to quantify water availability in the California Coastal Basins (CCBs). The CCBs vary greatly in their geologic, hydrologic, and climatic conditions; predominant water uses (agricultural, urban, or environmental); and how water availability changes in response to natural and anthropogenic stresses. Considering the complex dynamics of the CCBs and the history of managing water...

Date published: February 27, 2019
Status: Active

Groundwater Age

The age of groundwater is key in predicting which contaminants it might contain. There are many tracers and techniques that allow us to estimate the age—or mix of ages—of the groundwater we depend on as a drinking water supply.