 The Etowah Water Bank proposes to develop a large ASR well-field in west-central Georgia, supplementing the yield of storage facilities in northwest Georgia. Our history in this area is young, beginning only about 140 million years ago during the Cretaceous Age. Erosion of the Piedmont granite rocks formed Coastal Plain deposits of gravel, sand and clay that extend in ever-thickening layers from the Fall Line to the Atlantic and Gulf coasts. The Fall Line is where the Piedmont granite rocks are exposed, often forming waterfalls, and it extends from Montgomery, Alabama, to Columbus, Georgia, to Macon, Georgia, and on up the Eastern Seaboard.
Approximately 1,000 square miles of Taylor, Marion, Stewart, Chattahoochee, Quitman and Schley counties of west-central Georgia between the Flint and Chattahoochee Rivers are of primary interest for underground water storage purposes. Specific geologic strata include the sands of the Tuscaloosa, Eutaw, Blufftown, and Cusseta formations. Well depths would range from 400 up to about 1,200 feet below land surface, including strata that are under confined or semi-confined conditions. These strata become progressively more brackish and less productive in a southeastwardly direction. The coarse-grained character of these sands is conducive to high production rates. Currently there are few local water users of the aquifer system in this area.
 During severe droughts Etowah Water Bank wells in this area would pump water into tributaries to the Chattahoochee and Flint Rivers, ensuring an adequate flow at the Florida State Line and thereby protecting shellfish in Apalachicola Bay and powerplant cooling water requirements for Alabama. An equal volume of water would be reallocated from Lake Lanier to meet the water supply needs of the Atlanta area during droughts, at the same flow rate.
The Etowah Water Bank will provide a cost-effective supplemental supply of water to the Atlanta urban area while protecting the downstream ecosystem needs of Florida and also sustaining reliable water supplies for Alabama for downstream water users on the Coosa and Chattahoochee rivers. In conjunction with existing and planned surface reservoirs, the Etowah Water Bank will form and maintain a very large subsurface reservoir. Effective integration of these water sources with existing and any new surface reservoirs will provide a reliable, sustainable water supply for all water users.
Faced with the growing need for sustainable, reliable water supplies, more than 95 communities, farmers and industries nationwide are now storing drinking water underground in wells such as those proposed by the Etowah Water Bank. These wells are in confined and unconfined aquifers; fresh, brackish and saline aquifers; and at depths ranging from less than 100 feet to as much as 2,700 feet. Some of these water banks are quite large, such as Las Vegas, San Antonio, Calleguas Municipal Water District in southern California and the Kern Water Bank in southern California. Others are as small as a single well. Agricultural use of ASR is now being implemented in areas of the United States where groundwater supplies have been depleted. Industrial use of ASR for cooling water is increasingly common.
Unlike many other parts of the world where groundwater levels are declining rapidly due to excessive production and inadequate recharge, the Etowah Water Bank will not mine water. The Bank will recover only up to the cumulative volume that has previously been stored. In this way existing groundwater resources in this area will be preserved and protected. Following severe droughts groundwater levels will be quickly restored through recharge of treated drinking water into the Etowah Water Bank wells.
Supplemental underground storage will also be provided in northwest Georgia, storing seasonably available drinking water in dolomite and limestone aquifers that underlie approximately 1,000 square miles of this area. Stored water will be recovered during droughts, augmenting streamflows and also supplementing water supplies for the Atlanta area. |
