• Research Topics

  • Streamflow
  • Groundwater
  • Evaporative Loss
  • Water Use
  • Ecological Water
  • Water Quality

• Focus Area Studies

  • Apalachicola-Chattahoochee-Flint Basin
  • Colorado River Basin
  • Delaware River Basin

• Pilot Studies

  • Southwest Alluvial Basins
  • Great Lakes (U.S.)

USGS WaterSMART activities

• • Resources/Links

Groundwater

Overview

Regional Aquifer Studies

A major element of the Water Census is regional analyses of groundwater availability. Current plans call for studies of 30–40 principal aquifers that collectively account for more than 90 percent of the Nation's total groundwater withdrawals. The regional scale of these studies enables information to be integrated and consistent, so the resource can be analyzed and understood on an aquifer–wide scale. Therefore, it provides decision–makers with a better understanding of the status and trends in the Nation's groundwater availability. Additionally, the USGS has outlined an approach for developing an understanding of future groundwater availability builds on regional scale studies and current knowledge of groundwater availability at the national scale (Reilly and others, 2008).

Map of U.S. Geological Survey (USGS) Groundwater Resources Program regional scale groundwater study areas. Explanation indicates the fiscal years during which the studies are planned to occur. (Updated January 2013) - click to enlarge

Budgeting Recharge, Storage, and Discharge Rates

In addition, the Water Census will develop estimates of groundwater recharge, storage, and discharge at the watershed scale, as much as possible. These estimates will be made using a combination of information from large–scale studies being conducted by the USGS Groundwater Resources Program, observed data on groundwater levels collected in well networks, analysis of streamflow records, and other available information.

Glacial Aquifers

The Water Census funding in 2011 provided an opportunity to accelerate regional aquifer assessment with assessment of the glacial aquifer system that extends across all or parts of 25 northern States from Maine to Washington and Alaska. The glacial deposits are the source for the largest withdrawals for public and domestic supply in the United States. An estimated 22.5 million people rely on the glacial aquifer system for their drinking water.

Brackish Water Sources

Brackish groundwater as a resource for direct use or for desalination potentially represents an increasingly important component of the Nation's water supply. Relatively little is known, however, about brackish groundwater as compared to fresh groundwater. A better understanding of the distribution and character of brackish groundwater can provide information for future development of this resource. To satisfy requirements of the SECURE Water Act, the Water Census provided funding in 2012 to explore available information for developing a national brackish groundwater assessment.

References

Reilly, T.E., Dennehy, K.F., Alley, W.M., and Cunningham, W.L., 2008, Ground-water availability in the United States: U.S. Geological Survey Circular 1323, 70 p.