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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.

Filter Total Items: 77

Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project

The USGS seeks to increase understanding of the groundwater system in the vicinity of the Lower Colorado Water Supply Project well field and to estimate future groundwater levels and total dissolved solids concentrations in the wells and the long-term viability of the Lower Colorado Water Supply Project.
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Forecasting Total Dissolved Solids Concentrations of Groundwater from the Lower Colorado Water Supply Project

The USGS seeks to increase understanding of the groundwater system in the vicinity of the Lower Colorado Water Supply Project well field and to estimate future groundwater levels and total dissolved solids concentrations in the wells and the long-term viability of the Lower Colorado Water Supply Project.
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California Drought

The USGS closely monitors the effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information that takes into account long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues...
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California Drought

The USGS closely monitors the effects of drought through data collection and research. USGS science supports water managers in preparing for possible future drought by providing information that takes into account long-term hydrologic, climatic, and environmental changes. These studies support successful planning and science-based decision-making by water managers who must address complex issues...
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Los Angeles Coastal Plain Groundwater-flow Model

The Los Angeles Coastal Plain Groundwater-flow Model (LACPGM) is a tool to help water managers better understand groundwater flow and seawater intrusion in the Los Angeles coastal plain basins. It is the culmination of years of data collection and studies in the area and builds on our understanding of the area’s geology and hydrology obtained through the geologic and groundwater flow models.
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Los Angeles Coastal Plain Groundwater-flow Model

The Los Angeles Coastal Plain Groundwater-flow Model (LACPGM) is a tool to help water managers better understand groundwater flow and seawater intrusion in the Los Angeles coastal plain basins. It is the culmination of years of data collection and studies in the area and builds on our understanding of the area’s geology and hydrology obtained through the geologic and groundwater flow models.
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Hydrogeological Evaluation of the Edwards Air Force Base Air Force Research Laboratory Area, Antelope Valley, California

In cooperation with Air Force Civil Engineer Center (AFCEC), the U.S. Geological Survey (USGS) is evaluating the hydrogeology of the Air Force Research Laboratory (AFRL) and Site 25 areas of Edwards Air Force Base (EAFB) and the adjacent North-Muroc groundwater subbasin to help determine regional groundwater movement and the possible long-term movement and pathways of contaminated water from the...
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Hydrogeological Evaluation of the Edwards Air Force Base Air Force Research Laboratory Area, Antelope Valley, California

In cooperation with Air Force Civil Engineer Center (AFCEC), the U.S. Geological Survey (USGS) is evaluating the hydrogeology of the Air Force Research Laboratory (AFRL) and Site 25 areas of Edwards Air Force Base (EAFB) and the adjacent North-Muroc groundwater subbasin to help determine regional groundwater movement and the possible long-term movement and pathways of contaminated water from the...
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Evaluation of Groundwater Resources in the Adelaida Area of San Luis Obispo County, California

Stakeholders in San Luis Obispo County are concerned that the increased demand for water use has, and will continue to, affect groundwater levels and availability in the Adelaida area. To address stakeholder concerns, the County of San Luis Obispo Board of Supervisors has asked the USGS to conduct a comprehensive evaluation of groundwater resources of the Adelaida area.
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Evaluation of Groundwater Resources in the Adelaida Area of San Luis Obispo County, California

Stakeholders in San Luis Obispo County are concerned that the increased demand for water use has, and will continue to, affect groundwater levels and availability in the Adelaida area. To address stakeholder concerns, the County of San Luis Obispo Board of Supervisors has asked the USGS to conduct a comprehensive evaluation of groundwater resources of the Adelaida area.
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MODFLOW One-Water Hydrologic Flow Model—Conjunctive Use Simulation Software (MF-OWHM)

The MODLFOW One-Water Hydrologic Flow Model (MF-OWHM) Conjunctive Use Simulation Software (Boyce and others, 2020; Hanson and others, 2014) is a MODFLOW-2005-based integrated hydrologic flow model (IHM) that is the most complete version, to date, of the MODFLOW family of hydrologic simulators needed for the analysis of a broad range of conjunctive-use issues.
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MODFLOW One-Water Hydrologic Flow Model—Conjunctive Use Simulation Software (MF-OWHM)

The MODLFOW One-Water Hydrologic Flow Model (MF-OWHM) Conjunctive Use Simulation Software (Boyce and others, 2020; Hanson and others, 2014) is a MODFLOW-2005-based integrated hydrologic flow model (IHM) that is the most complete version, to date, of the MODFLOW family of hydrologic simulators needed for the analysis of a broad range of conjunctive-use issues.
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Evaluation of groundwater resources of the Anza-Terwilliger area, Anza, California

Groundwater is the sole source for water use to the rural community and two Native American tribes in the Cahuilla Valley and Terwilliger Valley groundwater basins, which are located approximately 35 miles southwest of Palm Springs, California. The characteristics and sustainable yield of the basins are not well understood and are threatened by increasing water use and potential changes in water...
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Evaluation of groundwater resources of the Anza-Terwilliger area, Anza, California

Groundwater is the sole source for water use to the rural community and two Native American tribes in the Cahuilla Valley and Terwilliger Valley groundwater basins, which are located approximately 35 miles southwest of Palm Springs, California. The characteristics and sustainable yield of the basins are not well understood and are threatened by increasing water use and potential changes in water...
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San Diego Hydrogeology

This is the first comprehensive geologic and hydrologic study for the San Diego area. This study will provide the integrated hydrogeologic knowledge necessary in this important and highly visible area of the United States and will serve as a role model for similar coastal settings throughout the world that have modest rainfall and small aquifers. Locally, results will help state and federal...
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San Diego Hydrogeology

This is the first comprehensive geologic and hydrologic study for the San Diego area. This study will provide the integrated hydrogeologic knowledge necessary in this important and highly visible area of the United States and will serve as a role model for similar coastal settings throughout the world that have modest rainfall and small aquifers. Locally, results will help state and federal...
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Groundwater Ambient Monitoring & Assessment (GAMA)

The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the quality of...
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Groundwater Ambient Monitoring & Assessment (GAMA)

The Groundwater Ambient Monitoring and Assessment Program’s Priority Basin Project (GAMA-PBP) was established by the California State Water Resources Control Board (SWRCB) in response to the Ground-Water Quality Monitoring Act of 2001 (Sections 10780-10782.3 of the California Water Code). The USGS is the technical lead for the GAMA-PBP and between 2004-2012 focused on characterizing the quality of...
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Regional Groundwater Availability Study of the California Coastal Basins

This study seeks to quantify water availability in the California Coastal Basins (CCBs). The CCBs vary greatly in their geologic, hydrologic, and climatic conditions; predominant water uses (agricultural, urban, or environmental); and how water availability changes in response to natural and anthropogenic stresses. Considering the complex dynamics of the CCBs and the history of managing water...
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Regional Groundwater Availability Study of the California Coastal Basins

This study seeks to quantify water availability in the California Coastal Basins (CCBs). The CCBs vary greatly in their geologic, hydrologic, and climatic conditions; predominant water uses (agricultural, urban, or environmental); and how water availability changes in response to natural and anthropogenic stresses. Considering the complex dynamics of the CCBs and the history of managing water...
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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.
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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.
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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...
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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...
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