The Senator Wash Dam and Reservoir is an off-stream reservoir constructed in the 1960s to store water from the Colorado River, upstream of the Imperial Dam, for emergency purposes, before the river disappears across the border into Mexico. In case of a shortage, water from the reservoir can be sent to the Imperial Valley Irrigation District, which is fed by Colorado River water via the All American Canal, and begins at the Imperial Dam. A power plant at the Senator Wash dam has reversible turbines that pump water up to keep the reservoir filled, and that generates less than 20 megawatts when water flows back down through the plant.