Tennessee Valley Authority. Watts Bar Dam hydroelectric plant. A husky ironworker at TVA's Watts Bar steam plant, directs the hoisting of a section for a 16-foot by 60-foot stack. This plant will supplement the big hydroelectric installation at Watts Bar Dam, which has an authorized output of 90,000 kilowatts, and a possible ultimate of 150,000 kilowatts. Each of the four big turbo-generators in the steam plant is rated at 60,000 kilowatts