The Army Corps of Engineers built this flood control dam and reservoir on the Osage River, starting in 1964. It took 15 years to complete, mostly due to the extensive removal and relocating of people, towns, roads and bridges over the 56,000 acre reservoir area. The dam was complete in 1979, and its powerhouse used six reversible turbines to generate 160 megawatts of power and to pump water back through the dam from its afterbay. The afterbay is an arm of the similarly sized but massively redeveloped Lake of the Ozarks, also formed by a dam on the Osage River. This pump-back function was not engaged for years, due to environmental and technical problems that have impeded its use.