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
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 making decisions.
Historical Floods
Historical Floods
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.
Golden State Reflections
Golden State Reflections
Our science supports the Department’s commitment to national resilience and resource management by providing expertise and delivering well-documented data and interpretive products.
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
From Streamgage to Smartphone
From Streamgage to Smartphone
A More Intelligent World
A More Intelligent World
As Wildfires Burn, Rainfall Can Strip Oxygen From Rivers, Killing Fish
As Wildfires Burn, Rainfall Can Strip Oxygen From Rivers, Killing Fish
Publications
Evaluation and synthesis of the Yolo Bypass fish monitoring program Evaluation and synthesis of the Yolo Bypass fish monitoring program
The Yolo Bypass is the largest functional remnant floodplain of the Sacramento River, providing benefits to aquatic taxa of the San Francisco Bay and Sacramento–San Joaquin Delta (hereafter, Bay-Delta). Because of the Yolo Bypass’s vital role in flood control and its ecological effects, the California Department of Water Resources started the Yolo Bypass Fish Monitoring Program (YBFMP)...
Field sampling guidelines for developing and verifying satellite remote sensing chlorophyll a concentration and fluorescence models in inland waters Field sampling guidelines for developing and verifying satellite remote sensing chlorophyll a concentration and fluorescence models in inland waters
Harmful algal blooms are increasing in frequency in inland waters across the United States, resulting in a need to monitor phytoplankton bloom events to track ecosystem health and productivity. Remote sensing of chlorophyll a values offers a cost-effective and powerful method for early detection and characterization of bloom events and serves as an overall indicator of water quality and...
Assessing the status and drivers of phytoplankton blooms along the riverine to freshwater-tidal continuum in a modified delta Assessing the status and drivers of phytoplankton blooms along the riverine to freshwater-tidal continuum in a modified delta
Shifts in phytoplankton communities, from beneficial taxa that fuel food webs to harmful taxa that degrade water quality, are often linked to anthropogenic modifications to estuaries. We analyzed monitoring data from 2000 to 2023 in the heavily modified southern, landward portion of the Sacramento-San Joaquin Delta (California, USA) to determine the status and drivers of phytoplankton...
Science
Santa Ana River Native Fish Study
Native Fish Population and Habitat Study, Santa Ana River, California The Santa Ana River stretches approximately 96 miles (154 kilometers) from its headwaters in the San Bernardino Mountains to its mouth at the Pacific Ocean near Huntington Beach, flowing through high desert and dense urban development in San Bernardino, Riverside, and Orange Counties. Native fish, also known as indigenous fish...
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.
WaterMAP: Water Monitoring Above the Planet
WaterMAP, or Water Monitoring Above the Planet, is an interactive web application that brings together surface water observations across the U.S. The application allows users to explore water conditions over time using both remotely sensed satellite and field measured data.