Web Tools

The USGS first identified uranium as a potential issue in California's groundwater during studies conducted in the Modesto area funded by the USGS National Water Quality Assessment Program. Subsequently, the GAMA program undertook a broader analysis of uranium concentrations across the State.

Arsenic is known to be a problem in groundwater used for drinking water supplies in the San Joaquin Valley. About 10% of the are of groundwater resources used for public supply contain more than the USEPA MCL of 10 µg/L. Most public-supply and domestic wells currently yield groundwater with arsenic levels below 3 µg/L and do not exhibit trends in concentration.

This interactive webmap shows USGS dam removal monitoring locations in the Klamath River basin. Monitoring activities include: suspended-sediment, macroinvertebrates, suspended sediment sampling, topographic surveying, bathymetric surveying, geomorphologic mapping, and riparian vegetation mapping.

Data viewer that allows users to see the streamflow and water quality monitoring sites at Clear Lake and its tributaries. Data is from the USGS National Water Information System and California Department of Water Resources and Lake County databases.

The Lake Tahoe Hydro Mapper is web-based application that provides access to real-time and historical data for Lake Tahoe and surrounding areas.

Wildfires pose significant threat in an increasingly arid California landscape, threatening life, property, and air quality, and having long-term impacts on the state's water. Knowing the location and extent of wildfire events that effect California may help scientists and resource managers predict and manage potential impacts burns may have upon water quality, availability and movement.

Take a 3D tour along the Mojave River and learn about its contribution to groundwater and surface water supply and the geologic characteristics that control it.

The National Water Dashboard (NWD) is a mobile, interactive tool that provides real-time information on water levels, weather, and flood forecasts - all in one place on a computer, smartphone, or other mobile device. The NWD presents real-time stream, lake and reservoir, precipitation, and groundwater data from more than 13,500 USGS observation stations across the country.

San Francisco Bay-Delta Water Quality, Nutrient, and Phytoplankton Mapping, 2018-2020-2021-2022-2023-2024 Comparison

A majority of the water in the western U.S. comes from snowmelt, but changes in the timing, magnitude, and duration of snowmelt can alter water availability downstream. This data visualization story explores what changing snowmelt means for water in the West, and how new USGS efforts can advance snow science by modeling snowpack and snowmelt dynamics and linking these results to streamflow.

Since 1969, USGS has collected water-quality data along the deep-channel longitudinal axis of the San Francisco Bay-Delta system at 37 fixed locations spaced 3-6 kilometers apart. The Water Quality of San Francisco Bay Data Query provides access to the entire dataset.

The USGS is conducting a comprehensive evaluation of groundwater resources of the Adelaida area. Use this map to explore the hydrogeology of the area, including land use, geology, and USGS hydrologic data by watershed or water management district.