Ground-Water Resources of the Middle Chattahoochee River Basin in Georgia and Alabama, and Upper Flint River Basin in Georgia: Subarea 2 of the Apalachicola-Chattahoochee-Flint and Alabama-Coosa-Tallapoosa River Basins.

摘要

Drought conditions in the 1980s focused attention on the multiple uses of the surface- and ground-water resources in the Apalachicola-Chattahoochee-Flint (ACF) and Alabama-Coosa-Tallapoosa (ACT) River basins in Georgia, Alabama, and Florida. State and Federal agencies also have proposed projects that would require additional water resources and revise operating practices within the river basins. The existing and proposed water projects create conflicting demands for water by the States and emphasize the problem of water-resource allocation. This study was initiated to describe ground-water availability in the middle Chattahoochee River in Georgia and Alabama, and upper Flint River in Georgia, Subarea 2 of the ACF and ACT River basins, and to estimate the possible effects of increased ground-water use within the basin. Subarea 2 encompasses about 4,100 square miles (mi2), which includes about 2,250 mi2 of the Chattahoochee River basin and 1,850 mi2 of the Flint River basin in the Piedmont physiographic province of west-central Georgia and eastern Alabama. Subarea 2 includes about 26 percent of the total 8,740 square-mile area of the Chattahoochee River basin and about 22 percent of the total 8,460 square-mile area of the Flint River basin. The study area is under-lain by a two-component aquifer system composed of a fractured, crystalline-rock aquifer characterized by little or no primary porosity or permeability; and the overlying weathered regolith (saprolite), which generally behaves as a porous-media aquifer. In some areas, a transition zone lies between the regolith and unweathered crystalline bedrock.