Granite Reef Diversion Dam is located about 4 miles downstream of the confluence of the Salt and Verde Rivers and about 22 miles east of Phoenix. The dam was constructed between 1906 and 1908 by Reclamation to divert water released from storage dams on the Salt and Verde Rivers to Salt River Project canals. The Arizona Canal serves the north side of the project; the South Canal serves the south side. From these two main canals, water is diverted to secondary canals, then to laterals through which water is delivered to farms, cities, and Indian tribes.
The dam is 1,128 feet long, and 29 feet high. The sluiceway contains four 15-by-9-foot slide gates on the North Side Canal, and two 15-by-9-foot slide gates on the South Side Canal. The North Side Canal headworks contain eighteen 7-by-5-foot slide gates, while the South Side headworks contain nine of these gates.