Water Security Agency

Lake Diefenbaker

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 Dam controls flows in the Qu’Appelle River and the Gardiner Dam controls flows in the South Saskatchewan River. The dams were officially opened July 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. 

Although more than 25 years have passed since Gardiner Dam was built, the multi-purpose structure continues to demonstrate its importance in storing, maintaining and controlling flows in the South Saskatchewan River. 

What is the South Saskatchewan River Project?

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

What is the capacity of the reservoir?

The Full Supply Level (FSL) of Lake Diefenbaker is 556.87 metres. 

Who owns the South Saskatchewan River Project? 

The Water Security Agency owns and operates the South Saskatchewan River Project and is directly responsible for its operation and maintenance.