The Chattahoochee begins as a small Appalachian spring in the Blue Ridge Mountains of North Georgia and from such humble beginnings flows for 434 miles until it combines with the Flint River, the two forming the Appalachicola River at the Georgia, Florida border. This river system is often referred to as the Appalachicola, Chattahoochee, Flint Basin, or the ACF.
The uppermost, headwater portion of the Chattahoochee begins in the Blue Ridge Mountains of Georgia, and a majority of this land area is located within the Chattahoochee National Forest. Approximately the first 8 miles of the Chattahoochee flows through the Blue Ridge MountainProvince and is characterized by swift velocities of water flow, course streambed material and frequency of riffle-pool patterns. Precipitation in this area ranges from 53 to 70 inches. This upper section of the Chattahoochee is free of impoundments. (Greenways)
As the Chattahoochee gains momentum it flows in a southwesterly arch through north and middle Georgia before it makes a dramatic turn to the south right at the border of Georgia and Alabama. From the border towns of Lannett, Alabama and West Point, Georgia, the river is shared between the two states on a southward course toward the Gulf of Mexico. This shared river will flow along Alabama’s boundary for 160 miles, until reaching the southeastern most corner of the state leaving Alabama and flowing into Florida. Before the construction of numerous hydropower dams the Chattahoochee’s journey between the Georgia and Alabama state line was once a rapid and dramatic descent over the Fall Line.
Of a total drainage area of 8,770 square miles, the portion of the Chattahoochee Valley in Alabama covers an area of 2,830 square miles or 32% of the total Chattahoochee Watershed area . This section of the river basin is about 35 miles across at its widest point. Principal tributaries are the Uchee, Cowikee and Abbie Creeks. Principal cities are Lanett, Phenix City, Eufala, and Dothan.
Major aquifers in the Alabama portions of the basin are the Libson, Nantafalia-Clayton, Providence-Ripley, and Tuscaloosa.
Most of the Valley in Alabama lies in the coastal plain and is characterized by low, rolling clay hills and sandy bottoms, ranging in elevation from 100 to 500 feet above mean sea level. In the thirty mile stretch north of Phenix City the river drops about 375 feet as the Chattahoochee crosses the fall line. Practically all of this fall has been developed for power generation by a series of privately owned dams between Phenix City and Lanett. Only a small part of the Alabama portion of the basin extends above the fall line into the red hills of the plateau, with elevations ranging up to 840 feet above mean sea level.
The watershed of the Chattahoochee touches 9 counties in AL (6 of which have eastern borders defined by the main stem of the Chattahoochee). These six are (in order N to S) Chambers, Lee, Russell, Barbour, Henry, and Houston. The other three that possess tributary streams to the Chattahoochee are Randolph, Macon, and Bullock.
There are thirteen hydroelectric dams in the Chattahoochee Basin (See Hydrologic Modifications).
Population changes in the upper portions of the Chattahoochee Basin have been significant. The Atlanta metropolitan area has increased from 500,000 people in 1950 to almost 3 million by 1990.
Water in the basin is increasingly under demand for agriculture, municipal and industrial water supply, navigation, power generation, recreation and the environment.
Annual average precipitation throughout the ACF is 45 inches.
Over half the water that falls as precipitation is returned to the atmosphere as evapotranspiration. The Chattahoochee Coastal Plain in Alabama is divided into the Chunnennuggee and Southern Red Hills geologic districts.
All the tribuataries to the Chattahoochee are free-flowing.
Flows average 47,500 cfs at West Point and Columbus. Historically these flows have been as low as 480 cfs and as high as 120,000.
Highest flows occur in late winter / early spring, February to April. Lowest flows occur in September.
At the fall line power projects the slope of the river increases significantly to 9 feet per mile. Downstream of Columbus the river becomes relatively flat with a slope of 1 foot per mile.
The Corps maintains a 9-foot-deep, 100-foot-wide navigation channel from Columbus, GA to the Gulf Intracoastal waterway.
Dam projects above Columbus were built to take advantage of natural stream gradients for power production.
The Chattahoochee occupies three physiographic regions. In the upper Chattahoochee the systems headwaters occupy the Blue Ridge province and then flow into the rolling hills of the Piedmont. At the Alabama / Georgia state line the Piedmont region rapidly transitions to the Southern Coastal Plain province.
Most abundant vegetative community in the basin. This forest type is found throughout most of central and northern Alabama. Upper canopy trees include: loblolly, shortleaf pine, shite oak, northern red oak, post oak, hickories, tulip poplar, persimmon, and eastern red cedar. Subcanopy species include: flowering dogwood, sourwood, eastern redbud, shadbush, black gum, American holly, blackberry, viburnums, sumacs, greebriars, grapes, and honeysuckle. (Corps)
Limited to the middle Chattahoochee in Alabama, in an area called the Black Belt. Dominated by Bluestem with 58 other herbaceous species. Maintained by periodic drought and floods and the occasional burns that prevent tree and shrub species from establishing. (Corps)