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: 121
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.

Date published: October 3, 2018
Status: Active

Implementing New Acoustic Monitoring Techniques in the Trinity River

Accurate river-sediment data is fundamental to planning and managing river restoration efforts on the Trinity River, and throughout the world’s waterways. The USGS has developed a “hydrophone” that enables scientists to listen to sediment particles as they move along the riverbed in order to inexpensively and reliably record near-continuous sediment-bedload-transport data. For this study,...

Date published: June 27, 2018
Status: Active

Low Intensity Chemical Dosing (LICD)

Rivers, wetlands, and agricultural operations supply natural organic material to the Sacramento-San Joaquin Delta (Delta) and the San Francisco Estuary. This natural organic matter provides many ecosystem benefits, but it also adversely affects drinking water. During drinking water treatment, chlorine added for purposes of pathogen control reacts with dissolved organic carbon (DOC) in the...

Contacts: Tamara Kraus, Phil Bachand
Date published: June 19, 2018
Status: Active

California Water Use

The U.S. Geological Survey's National Water-Use Information Program compiles the nation's water-use data at the county, state, and national levels. USGS five-year reports on national and state water-use estimates between 1950-2015 are posted on the web at: USGS water-use data for states and counties for...

Contacts: Justin Brandt
Date published: June 5, 2018
Status: Active

Post-Fire Flooding and Debris Flow

Fast-moving, highly destructive debris flows triggered by intense rainfall are one of the most dangerous post-fire hazards. The risk of floods and debris flows after fires increases due to vegetation loss and soil exposure. Cases of sudden and deadly debris flow are well documented along the western United States, particularly in ...

Date published: March 27, 2018
Status: Active

Assessing Deposit Build-up in Corte Madera Flood Control Channel

The Corte Madera Flood Control Channel was designed to prevent waters from overflowing Corte Madera Creek in a highly populated area of Marin County. Since the channel was last dredged in 1990 approximately 5,400 cubic feet of sediment has accumulated. The accumulation of sediment is of concern because the sediment may reduce the effectiveness of the channel, posing a flooding threat to...

Contacts: Daniel Livsey