Tennessee Valley Authority. A cover plate and exciter housing of a new generator unit in place at TVA's hydroelectric plant at Wilson Dam. Completed units show in the background. Located near Sheffield, Alabama, 260 miles above the the mouth of the Tennessee River, the dam had an authorized power installation of 288,000 kilowatts, which can be increased to a possible ultimate of 444,000 kilowatts. The reservoir at the dam adds 377,000 acre feet of water to controlled storage on the Tennesse River system