Water Quality
Providing foundational data and scientific analysis to address water quality issues facing California
Providing foundational data and scientific analysis to address water quality issues facing California
California Flood Science
Helping emergency managers and others protect life and property from floods and other water-related hazards
Helping emergency managers and others protect life and property from floods and other water-related hazards
Surface Water
Understanding the science about California surface-water use for irrigation, public consumption, and ecosystems
Understanding the science about California surface-water use for irrigation, public consumption, and ecosystems
Science Programs and Partnerships
Supplying necessary scientific information to local, state, and federal agencies, and non-governmental organizations
Supplying necessary scientific information to local, state, and federal agencies, and non-governmental organizations
Aquatic Ecology
Gaining better understanding of the effects that human activity, hydrologic extremes, and climate change have on aquatic ecosystems
Gaining better understanding of the effects that human activity, hydrologic extremes, and climate change have on aquatic ecosystems
Groundwater
Using science to assess and quantify the availability and quality of California's groundwater resources
Using science to assess and quantify the availability and quality of California's groundwater resources
California Drought
Monitoring the effects of drought in California through data collection and research
Monitoring the effects of drought in California through data collection and research
California Water Science Center
The U.S. Geological Survey, California Water Science Center 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 tribal, federal, state, and local agencies to assist them in managing California's water resources.
Large Storms & Floods in California History
Large Storms & Floods in California History
Storms unleash torrential rain and intense winds, posing significant challenges to infrastructure and triggering widespread flooding. Since it became a state in 1850, California has experienced numerous large storms and floods.
New Study on Mercury Contamination
New Study on Mercury Contamination
Legacy Mercury Contamination from Historical Gold Mining -- A visualization tool for spatial data on sediment, water, and biota in the Sierra Nevada, California
California Water & Drought Data
California Water & Drought Data
Basic hydrologic data collection, processing, analysis, dissemination, and archiving are major parts of the California Water Science Center program.
News
California Waters - Vol. V | Issue I
California Waters - Vol. V | Issue I
Protecting Protected Land from Pesticides
Protecting Protected Land from Pesticides
New Data on Salinas Valley Hydrology
New Data on Salinas Valley Hydrology
Publications
Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—Comparison of four (2018, 2020, 2021, 2022) spring high-resolution mapping surveys Assessing spatial variability of nutrients, phytoplankton, and related water-quality constituents in the California Sacramento–San Joaquin Delta at the landscape scale—Comparison of four (2018, 2020, 2021, 2022) spring high-resolution mapping surveys
Executive SummaryThis report summarizes results from boat-based, high-resolution water-quality mapping surveys completed before, during, and after upgrades to the EchoWater Resource Recovery Facility (EchoWater Facility), the regional wastewater facility for the City of Sacramento and surrounding areas, near Elk Grove, California. Surveys were completed in the tidal aquatic environments...
Pyrethroid insecticides implicated in mass mortality of monarch butterflies at an overwintering site in California Pyrethroid insecticides implicated in mass mortality of monarch butterflies at an overwintering site in California
Since the 1980s, monarch butterfly (Danaus plexippus plexippus) populations across North America have declined by 80–95%. Although several studies have implicated pesticides as a contributing factor to their population declines, our understanding of monarch exposure levels in nature remains limited. In January 2024, a mass mortality event near an overwintering site in Pacific Grove...
Public supply water delivery analysis and estimation for the conterminous United States Public supply water delivery analysis and estimation for the conterminous United States
Public supply water withdrawals represent 14% of all withdrawals in the conterminous United States (CONUS), supplying approximately 87% of the population with fresh water. Deliveries for public water supply are crucial for associating water use amounts with populations because they often differ from total withdrawals due to wholesales, transfers, losses, and other factors. Understanding...
Science
Sentinel Site Modeling
The California Department of Fish and Wildlife (CDFW) installed more than 40 climate and biodiversity monitoring stations, called sentinel sites, on public lands across the state. These sites collect detailed data on things like temperature, precipitation, soil moisture, and more to track how the environment is changing. Each site is meant to reflect conditions in the surrounding area, but...
Leading the Way: Specialized Laboratory Contributions to Environmental Health
The Environmental Health Program features a Unified Core Technology Team comprised of multiple laboratories with specialized expertise that support the overall program research assessing actual and perceived risks from environmental contaminants and pathogens. Individual Core Technology Teams work closely with the Integrated Science Teams to ensure current and emerging techniques are being used to...
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Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Columbia Environmental Research Center, Eastern Ecological Science Center, Kansas Water Science Center, Maryland-Delaware-D.C. Water Science Center, New England Water Science Center, New Jersey Water Science Center, Upper Midwest Water Science Center, Utah Water Science Center, Wetland and Aquatic Research Center
Decoding Harmful Algal Blooms: Unraveling the Mystery
Harmful algal blooms (HABs) are a significant environmental concern due to their potential effects on health, ecosystems, and economies. Algal toxins, which are toxic compounds produced by certain species of cyanobacteria and algae, are commonly linked to these blooms. It's important to note that algal toxins can still be present even when a bloom is not visible, highlighting the need for ongoing...
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Ecosystems Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Caribbean-Florida Water Science Center (CFWSC), Kansas Water Science Center, Maryland-Delaware-D.C. Water Science Center, National Wildlife Health Center, Nevada Water Science Center, New England Water Science Center, New Jersey Water Science Center, New Mexico Water Science Center, South Atlantic Water Science Center (SAWSC), St. Petersburg Coastal and Marine Science Center, Upper Midwest Environmental Sciences Center, Upper Midwest Water Science Center