This upstream area is bordered on the east by the Pinal Mountains and includes the town of Superior. The dam was built in 1960 to provide flood protection to farmland and developed areas including the communities of Chandler, Gilbert, Queen Creek, and Florence Junction and portions of Williams Air Force Base. The outlet works does not include any mechanical equipment that will permit significant adjustment to large outflows. Essentially the project operates for flood control automatically. Local interests, who have acquired these water rights, operate the slide gate to divert outflow from the reservoir into a irrigation ditch.
Diverted flows have an negligible impact on outflows from the dam during a flood event.
Large discharges occur following heavy rains in the area above the dam. Outflow usually percolates into the alluvial plain below the dam and rarely travels more than a few miles downstream. Only flows from very large and infrequent storms will drain into the Gila River at a location about 40 miles downstream from the dam.