Tennessee Valley Authority. Watts Bar Dam hydroelectric plant. Some of the 1,200 ampere oil circuit breakers in the switchyard of TVA's hydroelectric plant at Watts Bar Dam on the Tennessee River. Located 530 miles above the mouth of the Tennessee River, the dam has an authorized power installation of 90,000 kilowatts, which can be increased to a possible ultimate of 150,000 kilowatts. The reservoir at the dam adds 370,000 acre feet of water to controlled storage on the Tennessee River system