Bagnell Dam

 dam, hydroelectric power station/plant

Completed in 1931, the Bagnell Dam impounds the Osage River, creating the Lake of the Ozarks. The 148-foot tall concrete gravity dam was built by the for the purpose of hydroelectric power generation. It is 2,543 feet long, including a 520-foot long spillway and a 511-foot long power station. The facility has eight generators with a maximum capacity of 215 megawatts.

The original design called for thirteen floodgates. However only twelve floodgates were installed, and the thirteenth spillway opening is walled shut with concrete. The engineers calculated that twelve floodgates provided a large enough margin of safety. It may be apocryphal that officials did not want to jinx the dam with the unlucky number 13.