Senator Wash

The need for additional storage near Imperial Dam resulted in the construction of Senator Wash Dam on Senator Wash, a short distance upstream of Imperial Dam. Senator Wash is an off stream facility that pumps water to storage when there’s a surplus and generates power as it’s released back to the river to meet unforeseen demands. This facility was designed for use only in case of emergencies and is supplied normally by regulation of releases at Parker Dam. It has greatly improved the availability of water in these emergency situations as well as providing space for storage of unpredictable flood inflow.

The pumping and release capacities of the plant at 80 percent of maximum head are approximately 1,200 cfs, as compared to flows in the river that range from 2,000 cfs to 10,000 cfs. The capacity of the reservoir is approximately 14,000 AF. The USBR generally aims to maintain the reservoir storage at 50% capacity so that it can fill or draw from the reservoir storage as river flow dictates. Due to seepage problems along the reservoir levees, in 2001 the elevation was restricted to 240.00 feet above sea level, a reduction of 11 feet of elevation. Since the Senator Wash facility and the procedure for estimating and monitoring excess flow have been in operation, over-deliveries and wastes to the Gulf of California have been reduced.