California Water Science Center


The U.S. Geological Survey, California Water Science Center (CAWSC) provides reliable, impartial, foundational data and scientific analysis to address water issues facing California today. We conduct hydrologic monitoring and investigative studies in partnership with Federal, State, and local agencies to assist them in managing California's water resources.

Find out more about about CAWSC science programs and partnerships

Water Research Projects

Water Research Projects

Over 100 research projects addressing California's key water issues including: long-term water supply and availability, water quality, droughts and floods, climate change, aquatic ecology, the Delta, management of watersheds and groundwater.

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Partnering with Us

Partnering with Us

The USGS partners with local, state, and other federal agencies to provide scientific information needed by water-resources managers across the Nation.

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California Water Data

Basic hydrologic data collection, processing, analysis, dissemination, and archiving are major parts of the California Water Science Center program.

National Water Information System Mapper

Current California Streamflow Conditions

California Runoff

USGS WaterWatch

USGS Flood Event Viewer

California Post-Fire Debris-Flow Maps

California Water-Quality Mapper

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Date published: January 23, 2020

USGS Scientists Use Sound and Light to Measure Sediment in Water

In two recent publications, California Water Science Center scientists discuss their research using acoustic and optic technology to measure the quantity and movement of sediment in rivers and reservoirs.

Date published: December 9, 2019

USGS Hydrologist Collaborates with Danish Scientists on Groundwater Research

Groundwater provides much of the world's drinking water. When a supply of groundwater becomes contaminated, determining the timing and source of the contamination is an obvious concern. But the answers aren’t always clear. Contaminants may have different sources, even in a single groundwater well.

Date published: November 7, 2019

USGS Scientist to Discusses the Impacts of Agricultural Runoff in California’s Bay-Delta

Research Chemist, Dr. Michelle Hladik, presented her research on current-use pesticides being introduced into certain areas of California’s Bay-Delta ecosystem. Dr. Hladik’s presentation took place at the Society of Environmental Toxicology and Chemistry (SETAC) Annual...


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Year Published: 2020

Multiple-well monitoring site adjacent to the Lost Hills oil field, Kern County, California

The U.S. Geological Survey (USGS), in cooperation with the California State Water Resources Control Board, is evaluating several questions about oil and gas development and groundwater resources in California, including (1) the location of groundwater resources; (2) the proximity of oil and gas operations and groundwater and the geologic materials...

Everett, Rhett R.; Kjos, Adam; Brown, Anthony A.; Gillespie, Janice M.; McMahon, Peter B.
Everett, R.R., Kjos, A., Brown, A.A., Gillespie, J.M., and McMahon, P.B., 2020, Multiple-well monitoring site adjacent to the Lost Hills oil field, Kern County, California: U.S. Geological Survey Open-File Report 2019–1114, 8 p.,

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Year Published: 2020

Uptake, metabolism, and elimination of fungicides from coated wheat seeds in Japanese quail (Coturnix japonica)

Pesticides coated to the seed surface potentially pose an ecological risk to granivorous birds that consume incompletely buried or spilled seeds. To assess the toxicokinetics of seeds treated with current-use fungicides, Japanese quail (Coturnix japonica) were orally dosed with commercially coated wheat seeds. Quail were exposed to metalaxyl,...

Gross, Michael S.; Thomas G. Bean; Hladik, Michelle; Rattner, Barnett A.; Kuivila, Kathryn

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Year Published: 2020

Daily stream samples reveal highly complex pesticide occurrence and potential toxicity to aquatic life

Transient, acutely toxic concentrations of pesticides in streams can go undetected by fixed-interval sampling programs. Here we compare temporal patterns in occurrence of current-use pesticides in daily composite samples to those in weekly composite and weekly discrete samples of surface water from 14 small stream sites. Samples were collected...

Norman, Julia E.; Mahler, Barbara; Nowell, Lisa H.; Van Metre, Peter C.; Sandstrom, Mark W.; Corbin, Mark A.; Qian, Yaorong; Pankow, James F.; Luo, Wentai; Fitzgerald, Nicholas B.; Asher, William E.; McWhirter, Kevin J.