California Water Science Center

Surface Water

Streams, rivers, lakes and reservoirs - collectively referred to as surface water - are important natural resources for irrigation, public supply, wetlands and wildlife. Surface water is also measured as annual runoff, which is the amount of rain and snowmelt drainage left after the demands of nature, evaporation from land, and transpiration from vegetation have been supplied. It supplies most of our basic water needs.

Filter Total Items: 114
Date published: October 31, 2018
Status: Active

Improved Lower South Bay suspended-sediment flux measurements

Tidal marshes provide animal habitats and prevent erosion. Expanding towns and cities have claimed major parts of San Francisco Bay’s marshland. Sediment deposits are essential to rebuilding tidal marshes and keeping existing marshes intact. In the southern part of the Bay, the largest tidal wetland restoration project on the west coast is underway. Sediment flux measurements are key in...

Date published: October 29, 2018
Status: Archived

National Water-Quality Assessment (NAWQA) Program

During the past 25 years, industry and government made large financial investments in pollution control that have resulted in better water quality across the Nation; however, many water-quality problems remain. To address the need for consistent and scientifically sound information for managing the Nation's water resources the U.S. Geological Survey began a full-scale ...

Date published: October 29, 2018
Status: Completed

Development of Numeric Flow Criteria to Support Freshwater Biological Objectives and Hydrologic Modification Management in California's Wadeable Streams

The State Water Resources Control Board (SWRCB) of California has initiated a process to develop numerical biological objectives for wadeable freshwater streams and rivers for the entire state. Use of biological endpoints for regulatory or compliance purposes requires the ability to relate specific stressors...

Contacts: Larry Brown
Date published: October 29, 2018
Status: Active

Monitoring the Impacts of the Rim Fire on Tuolumne River Water Quality

The Rim Fire has burned over 400 square miles of the Tuolumne River and Merced River watersheds in central California and is now the 3rd largest wildfire in state history. The burn area is largely on the Tuolumne between Hetch Hetchy Reservoir and Don Pedro Reservoir, both of which serve as critical sources of drinking water and irrigation water to San Francisco Bay area and Central Valley...

Contacts: Scott A Wright
Date published: October 26, 2018
Status: Active

Determination of the geohydrologic characteristics of the boundary between the Mojave River and Antelope Valley groundwater basins, California

The Mojave Basin Area was adjudicated in 1993 and the Mojave Water Agency (MWA) was appointed as Watermaster to ensure that water rights are allocated according to the Court Judgment (Riverside County Superior Court, 1996). Established in 1960, the southwestern boundary of MWA’s management area is not a hydrologic boundary but instead coincides roughly with the boundary between San Bernardino...

Date published: October 26, 2018
Status: Active

Reservoir Sedimentation Related to Wildfire in the Sierra Nevada Mountains of California

Reservoirs naturally fill with sediment transported from the upstream watershed. As reservoirs fill with sediment, the amount of available water decreases for functions such as water supply, irrigation, flood control, and hydropower. In the Sierra Nevada Mountains of California, a large number of reservoirs are significantly affected by reservoir sedimentation (Minear and Kondolf 2009)....

Contacts: Justin Minear
Date published: October 26, 2018
Status: Completed

Atmospheric Deposition Contributions to Mercury Yields in Select Watersheds in the Western United States and Canada

The atmosphere plays an important role in the delivery to and cycling of mercury (Hg) in the environment and it can be a major source of Hg contamination to surface waters. Globally, atmospheric deposition of Hg is the primary source of Hg related concerns for human and ecosystem health (Fitzgerald and others, 1998). In California and other areas in the United States, Hg use in gold and silver...

Date published: October 24, 2018
Status: Active

Perchlorate Source Attribution Study in Zones 1-4 of the Stringfellow Superfund Site, Jurupa Valley, Riverside County, California

Between 1956 and 1972, the Stringfellow Hazardous Waste Site, Riverside County, Calif., discharged approximately 34 million gallons of industrial wastes to unlined surface impoundments located at the head of Pyrite Canyon. Contaminants from the site have been detected as far as 4 miles downgradient near the Santa Ana River. Perchlorate in excess of the California Maximum Contaminant Level of 6...

Date published: October 24, 2018
Status: Active

Monitoring Mercury and Methylmercury in Water, Sediment and Biota in Combie Reservoir Before and After Dredging and Mercury Removal

Dredging to maintain water storage capacity by the Nevada Irrigation District (NID) occurred at Lake Combie reservoir, one of several reservoirs along the Bear River, California over the past 40 years on an as-needed basis to maintain water storage capacity. Maintenance dredging operations were halted by the Central Valley Regional Water...

Date published: October 24, 2018
Status: Active

Assessing Suspended-Sediment Supply and Marsh Accretion in Humboldt Bay, CA

Suspended-sediment measurements are essential for coastal planning, resource management, and for assessing the sustainability of salt marshes in relation to expected sea-level rise. Suspended sediment can have positive or negative effects, depending on its characteristics and amount, and on the location and ecosystem services of interest. Sediment deposition in salt marshes helps sustain marsh...

Date published: October 24, 2018
Status: Active

Pesticides in Suspended Sediment of the Alamo and New Rivers

Previous studies have detected current-use pesticides and DDT metabolites in water and suspended sediments from the Alamo and New Rivers. Additional studies have found water samples from both rivers to be toxic to aquatic organisms in laboratory bioassays, and implicated certain current-use pesticides as the source of this toxicity. Recent requirements under the Clean Water Act for the...

Contacts: James Orlando
Date published: October 23, 2018
Status: Active

Lower American River Mercury

Dredging operations for gold along the American River began in the 1860s and continued through the early part of the 20th century, ending about 1962. More than one billion cubic yards of gravel were dredged, making the American River dredge field the second largest in California.