Granite Reef Diversion Dam

The purpose of the Granite Reef Diversion Dam is to divert water from the river into the canals north and south of the river for delivery to water users within the Project. No water is stored, and no power is generated at Granite Reef Dam. There are no recreational facilities.


Floods in April 1905 washed out the Arizona Dam, which diverted water for the canals on the north side of the Salt River. The loss of this diversion structure, which belonged to the Arizona Water Company, caused serious problems for the farmers under the Arizona Canal. But it also fortuitously led the federal government to buy the northside canal system and to construct the Granite Reef Diversion Dam.

Designed as a single point of diversion for all of the northside and southside canals, the concrete dam received authorization in July 1906. Construction began in October 1906 and was completed in May 1908. The dam is only 29 feet high and is 1,000 feet long.