South Saskatchewan River Project

Lake Diefenbaker is the largest body of water in southern Saskatchewan. It was formed by two dams, the Qu’Appelle River Dam and Gardiner Dam. The Qu’Appelle River Dam controls flows in the Qu’Appelle River and the Gardiner Dam controls flows in the South Saskatchewan River. The dams were officially opened June 21, 1967. The 64-metre tall, 5,000-metre long Gardiner Dam took nearly nine years to build and is one of the largest earthfill dams in the world.  

The project consists of the Gardiner Dam, located on the South Saskatchewan River, 25 kilometres downstream of Elbow, and Qu’Appelle River Dam, located 19 km southeast of Elbow and 45 km southeast of Gardiner Dam. It also includes Lake Diefenbaker, a 225 km long multi-purpose reservoir, which serves many varied interests. 

The full supply level of Lake Diefenbaker is 556.87 metres. At full suply, the reservoir stores approximately 9,400,000 cubic decametres of water. 

In addition to being a major recreation facility, Lake Diefenbaker provides domestic water for approximately 60 per cent of Saskatchewan people. Water is also stored for use by several potash mines, major irrigation projects, various industries and wildlife interests. The lake also plays an important role in power generation and flood control. 

The Water Security Agency owns and operates the South Saskatchewan River Project and is directly responsible for its operation and maintenance. WSA also owns and operates over 70 other dams throughout the province, including Rafferty and Grant Devine dams in southeastern Saskatchewan.