The Chattooga and Tallulah Rivers join in the Savannah River headwaters to form the Tugaloo River. Further downstream near Hartwell, Georgia, the Tugaloo River joins with the Seneca River from South Carolina to form the Savannah River. From here the Savannah River flows southeasterly to the Atlantic Ocean. Finally, at the terminus of the river is the Savannah River harbor.
The Savannah River, which is approximately 300 miles long, is the most extensively used surface water resource in the basin. It is fed by many moderate-sized tributaries, some of which have drainage areas greater than 200 square miles and are significant surface water resources in their own right.
The major impoundments in the basin are Hartwell Lake, Richard B. Russell Lake, and J. Strom Thurmond Lake (Clarks Hill Lake), all Corps of Engineers reservoirs.
Hartwell Lake is a 56,000 acre reservoir located at the confluence of Tugaloo River and Seneca River. Richard B. Russell Lake is a 26,000 acre reservoir just downstream from Hartwell Lake.