Hydrologic Modeling

The North Coast Resource Partnership (NCRP) is an innovative, stakeholder-driven collaboration among local government, Tribes, watershed groups, and interested partners in the North Coast region of California. The North Coast comprises seven counties, Tribal lands, major watersheds, and a planning area of 19,390 square miles representing 12% of California's landscape. The NCRP integrates long-term...

Currently, groundwater is the only source for domestic, agricultural and municipal water use in the Cuyama Valley groundwater basin in Santa Barbara County, California. Groundwater withdrawals, mainly to irrigate agricultural crops, have resulted in water-level declines of as much as 300 feet in the area since the 1940s. To plan for sustainable future use of the groundwater, the U.S. Geological...

Groundwater is effectively the sole source of water supply for Borrego Valley, California. By the mid-2000s, agriculture, recreation (predominantly golf courses), municipal uses, and the Anza-Borrego Desert State Park required about four times more water than is available through natural recharge. As a result, the U.S. Geological Survey began a cooperative study of the Borrego Valley with the...

The Owens Valley, a long, narrow valley along the east side of the Sierra Nevada in east-central California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River-Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or...

Prior to 2000, the four most abundant resident pelagic fishes in the study area included two native species, delta smelt (Hypomesus transpacificus) a federal listed endangered species, and longfin smelt (Spirinchus thaleicthys) a state listed endangered species, and two introduced species, threadfin shad (Dorosoma petenense) and age-0 striped bass (Morone saxatilis).

The city of Petaluma, located in the Petaluma Valley and home to about 12 percent of the population of Sonoma County, faces growth in population and demand for water. Water supply is provided primarily by water delivered via aqueduct from the Russian River; however, groundwater is a vital supplemental source of water for the city of Petaluma and is the primary source of supply for domestic and...

The Russian River Watershed covers 1,500 square miles of urban, agricultural and forested lands in northern Sonoma County and southern Mendocino County, California. Communities in the Russian River Watershed (RRW) depend on a combination of Russian River water and groundwater to meet their water-supply demands. Water is used primarily for agricultural irrigation, municipal and private wells supply...

The Chuckwalla Valley in the southern Mojave Desert in California has been selected as an area with high potential for solar energy development. Six large-scale solar energy projects are currently approved or proposed in this basin, the largest number of solar projects in any one basin in California. Water needs associated with proposed solar energy projects within the basin have generated...

Reclamation's Yuma Area Office (YAO) operates 50 plus drainage wells and 21 regulatory wells to control groundwater levels in low-lying flood plain areas and to supply a significant portion of the Colorado River water the United States (US) is required by treaty to deliver to Mexico.

Residents and businesses in Yucca Valley, CA rely currently on septic tanks to treat their wastewater. The local water district, Hi-Desert Water District (HDWD), is planning to construct a sewer system and wastewater treatment plant, initially serving the West, Midwest, Mideast, Northeast, and East hydrogeologic units of the Warren subbasin.

Sonoma County faces potential changes in surface-water availability, including potential impacts on water quality in response to changing land use, increasing population, and climate change.

The National Park Service (NPS) and USGS jointly will investigate impacts to the Merced River due to infrastructure and historic channel widening in east Yosemite Valley with a goal of constructing river management alternatives. Past management actions, such as gravel mining, channel riprap, and the construction of bridges that do not accommodate flood flows, have had long-lasting impacts to the...