Introduction

Reliable and impartial scientific information about the occurrence, quantity, quality, distribution, and movement of water is essential to resource managers, planners, and others throughout the Nation. The U.S. Geological Survey (USGS), in cooperation with numerous local, State, and Federal agencies, collects hydrologic data and conducts studies to monitor hydrologic conditions and better define the water resources of Georgia and other States and territories.

Groundwater-level and groundwater-quality data are essential for water-resources assessment and management. Water-level measurements from observation wells are the principal source of information about the hydrologic stresses on aquifers and how these stresses affect groundwater recharge, storage, and discharge. Long-term, systematic measurement of water levels provides essential data needed to evaluate changes over time, develop groundwater models, forecast trends, and design, implement, and monitor the effectiveness of groundwater management and protection programs (Taylor and Alley, 2001). Groundwater-quality data are necessary to protect groundwater resources, because deterioration of groundwater quality may be virtually irreversible, and treatment of contaminated groundwater can be expensive (Alley, 1993).

Map of Major Georgia Aquifiers

Purpose and Scope

This website presents an overview of groundwater levels throughout Georgia. It is a continuation of a series of reports begun in 1978. Water-level data are summarized in graphs and maps. Groundwater levels in major aquifers are presented on hydrographs for selected wells. Data from additional information about the wells included in this report can be obtained from the USGS National Water Information System (NWIS) database at http://waterdata.usgs.gov/ga/nwis/gw/.

Cooperating Organizations and Agencies

Groundwater monitoring in Georgia is conducted in cooperation with numerous local organizations, private companies, and State and Federal agencies. Cooperating organizations and agencies include the following:

  • City of Albany Utility Operations
  • Augusta Utilities Department, City of Augusta
  • Georgia Department of Natural Resources, Environmental Protection Division
  • Glynn County Joint Water and Sewer Commission
  • Miller Coors LLC

All of these organizations participate in the USGS Cooperative Water Program, an ongoing partnership between the USGS and State and local agencies. The program enables joint planning and funding for groundwater monitoring and systematic studies of water quantity, quality, and use. Data obtained from these studies are used to guide water-resources management and planning activities and provide indications of emerging water problems. A more complete description of the Cooperative Water Program is provided in Brooks (2004).

Linear Trend Lines and Regression Statistics

Water-level trend lines are generated by Simple Linear Regression. The "Simple Regression" button calculates the trend line for the current set of data displayed in the graph.
Dates with null values are not used in the trend line calculations.

η represents the sample size

y-intercept a = [ (∑y)(∑x2) - (∑x)(∑xy) ] / [ η(∑x2) - (∑x)2 ]

slope b = [ η(∑xy) - (∑x)(∑xy) ] / [ η(∑x2) - (∑x)2 ]

Arrow icons for the maps represent the upward or downward trend, and are calculated using the last 10 years of data. Simple Linear Regression is used to calculate the trend. If the well does not have 10 years of data, or if the trend is less than .01 ft/year, a circle icon is displayed, instead of an arrow.

Methods of Analysis, Sources of Data, and Data Accuracy

Continuous water-level data from wells throughout Georgia are presented in this report. Wells with electronic data loggers record water levels at 15-minute intervals; these data are field checked to verify that the electronic water level is within 0.05 foot (ft) of the manual measurement, and data are retrieved generally every 2 months. Wells that have real-time satellite telemetry record water levels at 15-minute intervals and are transmitted every 1 to 4 hours (based on the equipment). The data are available at https://waterdata.usgs.gov/ga/nwis/current/?type=gw (U.S. Geological Survey, 2018).

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88) or National Geodetic Vertical Datum of 1929. Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83) or North American Datum of 1927 (NAD 27). The datum information for each site are available at https://waterdata.usgs.gov/ga/nwis/current/?type=gw (U.S. Geological Survey, 2018).

Altitude, as used in this report, refers to distance above the vertical datum.

U.S. Geological Survey, 2017, National Water Information System database, accessed May 1, 2018, at https://doi.org/10.5066/F7P55KJN.

Groundwater Resources

Contrasting geologic features and landforms of the physiographic provinces of Georgia (see map on p. 7 and table on p. 8–9) affect the quantity and quality of groundwater throughout the State. The surficial aquifer system is present in each of the five physiographic provinces in Georgia. In the Coastal Plain Province, the surficial aquifer system consists of layered sand, clay, and in some places limestone. The surficial aquifer system typically is under water-table (unconfined) conditions and provides water for domestic and livestock use. The surficial aquifer system is semiconfined to confined locally in the coastal area. In the Piedmont, Blue Ridge, and Valley and Ridge Provinces, the surficial aquifer system consists of soil, saprolite, stream alluvium, colluvium, and other surficial deposits.

The most productive aquifers in Georgia are in the Coastal Plain Province in the southern half of the State. The Coastal Plain is underlain by alternating layers of sand, clay, dolomite, and limestone that dip and thicken to the southeast. Coastal Plain aquifers generally are confined, except near their northern limits where the aquifers crop out or are near land surface. Aquifers in the Coastal Plain include the surficial aquifer system, Brunswick aquifer system, Floridan aquifer system, Gordon aquifer, Claiborne aquifer, Clayton aquifer, and Cretaceous aquifer system.

In the Valley and Ridge Province, groundwater is transmitted through primary and secondary openings in folded and faulted sedimentary and metasedimentary rocks of Paleozoic age. In this report, the aquifers are referred to as “Paleozoic-rock aquifers.”

In the Piedmont and Blue Ridge Provinces, the geology is complex and consists of structurally deformed metamorphic and igneous rocks. Groundwater is transmitted through secondary openings along fractures, foliation, joints, contacts, or other features in the crystalline bedrock. In this report, the aquifers are referred to as “crystalline-rock aquifers.” A more complete discussion of the State’s groundwater resources is provided in Clarke and Pierce (1985).

References