Groundwater Supply
Groundwater Supply
Every day, millions of gallons of groundwater are pumped to supply drinking water for almost one-half of the Nation’s population. Groundwater is also critical to agriculture, one of California's main economic drivers. The California Water Science Center studies aquifers throughout the state that are critical sources of groundwater used for public supply. This research informs us about the quality and availability of groundwater for drinking, where and why groundwater quality is degraded, and where groundwater quality is changing.
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Groundwater Age
The age of groundwater is key in predicting which contaminants it might contain. There are many tracers and techniques that allow us to estimate the age—or mix of ages—of the groundwater we depend on as a drinking water supply.
Salinas and Carmel River Basins Study
Together, the Salinas and Carmel river basins include some of the world’s most fertile agricultural lands and are internationally known for their natural beauty; ecological diversity; multi-national cultural history; and recreation opportunities such as fishing, auto racing, and golfing. The area is oftentimes referred to as the “Salad Bowl of the World” or “America’s Salad Bowl” because of the...
Salinas and Carmel Rivers Basin Study: Paso Robles Model Update
The existing Paso Robles Basin Model (PRBM) needed to be updated and enhanced to achieve the timeline and objectives of the Salinas Carmel River Basin Study (SCRBS) for the U.S. Bureau of Reclamation (Reclamation) and local partners.
SGMApy: An open source platform for computing sustainability metrics and visualizing MODFLOW data
Climate change and demographic changes have underscored the need to improve effectiveness of managing valuable water resources for sustainability. In 2014, the Sustainable Groundwater Management Act (SGMA) established a framework for sustainable, local groundwater management. SGMA requires groundwater-dependent regions to halt overdraft and bring basins into balanced levels of pumping and recharge...
Pajaro Valley Hydrologic Model Update, Data Collection, and Analysis for Sustainability
The Pajaro Valley is home to a billion-dollar agricultural industry, providing food and food processing services for the nation. The water for these enterprises is supplied, in large part, by the groundwater resources (aquifers) in the area. The Pajaro Valley Water Management Agency (PV Water) and the USGS have partnered to improve aquifer monitoring software, allowing better quantification and...
Using the Basin Characterization Model (BCM) to Estimate Natural Recharge in Indian Wells Valley, California
Located in the northern Mojave Desert, the Indian Wells Valley has an arid environment, receiving only 4-6 inches of precipitation annually. Like most desert areas, Indian Wells Valley communities rely mostly on groundwater for their available groundwater supply. Increases in urban and agricultural development have resulted in increased groundwater pumpage for public and agricultural use, causing...
Cuyama Valley Water Availability Study
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...
Borrego Valley Groundwater Conditions
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...
Owens Valley Hydrogeology
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...
Sustainable Groundwater Management
In 2014, the State of California adopted historic legislation to help manage its groundwater, the Sustainable Groundwater Management Act (SGMA) . According to the act, local Groundwater Sustainability Agencies (GSAs) must be formed for all high and medium priority basins in the state. These GSAs must develop and implement Groundwater Sustainability Plans (GSPs) for managing and using groundwater...
Evaluation of the groundwater resources of the Petaluma Valley
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...
Relation of Groundwater Age to Herbicide Concentration Trends in Fresno and Tulare Counties, California
The California Department of Pesticide Regulation (DPR) has been monitoring pesticide concentrations in about 70 domestic drinking water wells located in vulnerable areas of Fresno and Tulare Counties for approximately 15 years. A recent analysis of the monitoring data indicated that there were decreases in simazine, diuron, and bromacil concentrations in many wells during 2000-2010.