The John W. Keys III Pump-Generating Plant is a hydroelectric facility at the Grand Coulee Dam, in Washington state, that pumps water out of Lake Roosevelt, the part of the Columbia River flooded by the dam, up to Banks Lake, 280 feet above the level of Lake Roosevelt. Water travels through a network of canals from Banks Lake to irrigate hundreds of thousands of acres of farmland, made arable by this massive US Department of Reclamation project at Grand Coulee. The John W. Keys III Pump-Generating Plant was completed in 1951, originally as just a pumping facility. Reversible pump-generating units gradually replaced the pumps over a ten year period, ending in 1984, and the plant now has the capacity to generate 314 megawatts when water flows out of Banks Lake. The Grand Coulee Dam, completed in 1942, has three other hydroelectric plants connected to it that together can generate a much as 6,600 megawatts, making the dam the largest power station of any kind in the USA.