Water Quality

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 Quality Control Board (CVRWQCB) in 2002 because of elevated...

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...

The Joshua Basin Water District (JBWD) is implementing an artificial groundwater recharge program to reverse the decline of groundwater levels and to store water in the Joshua Tree groundwater subbasin of the Morongo groundwater basin (~100 mi east of Los Angeles, CA).

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 Regional...

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.

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...

This study assesses the quality of water in the Yucaipa area, primarily in the Yucaipa plain. This hydrogeology study will aid local water purveyors in understanding and evaluating local resources and using those resources effectively in combination with water imported from northern California and from the adjacent San Bernardino area.

Pesticides are used in both agricultural and urban settings to manage unwanted plants, insects, fungi, and other pests. However, these substances and their breakdown products can move beyond their intended application sites through various means, ending up in areas where they weren't meant to be. This movement can happen via the air, through water (both surface and groundwater), and by sticking to...

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 water to...

About half of the water supply in the southwestern United States is supplied by water from forests, which generally yield higher quality water than any other source. Approximately 80 percent of the freshwater resources in the U.S. originate on forested land, and more than 3,400 public drinking-water systems are located in watersheds containing national forest lands (USDA, 2006). More than 12...

A serious consequence of wildfires is the erosion which occurs during storm events in areas where vegetation has been burned away. In cases where such land is near a creek or stream, mercury (Hg) and other contaminants from the eroding soil can make their way into the waterways, impacting the health of fish and wildlife, and the quality of the water supply for local communities (see: USGS Fact...

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...