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Aquatic Ecology

Gaining better understanding of the effects that human activity, hydrologic extremes, and climate change have on aquatic ecosystems

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Groundwater

Using science to assess and quantify the availability and quality of California's groundwater resources

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Science Programs and Partnerships

Supplying necessary scientific information to local, state, and federal agencies, and non-governmental organizations

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Water Quality

Providing foundational data and scientific analysis to address water quality issues facing California

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Surface Water

Understanding the science about California surface-water use for irrigation, public consumption, and ecosystems

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California Flood Science

Helping emergency managers and others protect life and property from floods and other water-related hazards

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California Drought

Monitoring the effects of drought in California through data collection and research

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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.

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Wetland Restoration on Molokaʻi

A woman stands in the distance of a coastal wetland covered in pickleweed

A new study by USGS Research Hydrologist, Dr. Judith Drexler, details actions needed for re-establishing coastal wetlands on Molokaʻi, Hawaiʻi.

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Join the USGS Team

Hydrologic technicians, Kyle Nakatsuka and Thomas Jetson, deploying a flow sensor on a shoal in San Francisco Bay.

Explore careers at the USGS, experience a day in the life of employees, navigate USAJobs, and see frequent questions on Federal hiring.

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California Water & Drought Data

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

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News

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California Water Science Center Returns to ACWA

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California Waters - Fall 2023 - Vol. III | Issue III

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USGS Youth Outreach at Expanding Your Horizons Conference

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Publications

A novel boat-based field application of a high-frequency conductometric ammonium analyzer to characterize spatial variation in aquatic ecosystems

Documenting dissolved inorganic nitrogen (DIN) concentration and form at appropriate temporal and spatial scales is key to understanding aquatic ecosystem health, particularly as DIN fuels primary productivity. In addition to point and non-point source nutrient inputs, factors such as hydrology, geomorphology, temperature, light, and biogeochemical transformations influence nutrient dynamics in su
Authors
Emily Teresa Richardson, Angela Hansen, Tamara E. C. Kraus, Bryan D. Downing, Don Forsberg, John Stillian, Katy O'Donnell, Crystal Lee Sturgeon, Brian A. Bergamaschi
By
Water Resources Mission Area, California Water Science Center

Multiple-well monitoring site adjacent to the Elk Hills Oil Field, Kern County, California

IntroductionThe Elk Hills Oil Field is one of the many fields selected for regional groundwater mapping and monitoring by the California State Water Resources Control Board as part of the Oil and Gas Regional Monitoring Program (California State Water Resources Control Board, 2015, 2022b; U.S. Geological Survey, 2022a). The U.S. Geological Survey (USGS), in cooperation with the California State Wa
Authors
Rhett R. Everett, Janice M. Gillespie, Mackenzie M. Shepherd, Andrew Y. Morita, Maryanne Bobbitt, Christopher A. Kohel, John G. Warden
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Water Resources Mission Area, California Water Science Center

An agricultural package for MODFLOW 6 using the Application Programming Interface

An agricultural water use package has been developed for MODFLOW 6 using the MODFLOW Application Programming Interface (API). The MODFLOW API Agricultural Water Use Package (API-Ag) was based on the approach to simulate irrigation demand in the MODFLOW-NWT and GSFLOW Agricultural Water Use (AG) Package. The API-Ag Package differs from the previous approach by implementing new features and support
Authors
Joshua Larsen, Christian D. Langevin, Joseph D. Hughes, Richard G. Niswonger
By
Water Resources Mission Area, California Water Science Center
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Science

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Image: Looking South at the Salton Sea

Water Availability of the Salton Sea Watershed

Throughout history, the Salton Sea has formed and dried up due to flooding from the Colorado River. It was most recently formed in 1905 when the Colorado River broke through an irrigation canal and flowed uncontrolled into the Salton Sea watershed. The Salton Sea is a terminal lake (it has no outlets). It is also in transboundary watershed, with area in both the state of California and Mexico’s...
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California Water Science Center
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Water Availability of the Salton Sea Watershed

Throughout history, the Salton Sea has formed and dried up due to flooding from the Colorado River. It was most recently formed in 1905 when the Colorado River broke through an irrigation canal and flowed uncontrolled into the Salton Sea watershed. The Salton Sea is a terminal lake (it has no outlets). It is also in transboundary watershed, with area in both the state of California and Mexico’s...
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Forest of dead trees. No live vegetation anywhere.

Hazards Summary for Mammoth Mountain

Pyroclastic flow and carbon dioxide hazards at Mammoth Mountain.
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California Water Science Center, Mammoth Mountain
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Hazards Summary for Mammoth Mountain

Pyroclastic flow and carbon dioxide hazards at Mammoth Mountain.
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Lake Oroville showing extremely low water under the Enterprise Bridge during 2021 drought.

About Drought

The USGS closely monitors the effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information that takes into account long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues...
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California Water Science Center, Land Subsidence in California
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About Drought

The USGS closely monitors the effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information that takes into account long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues...
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