John W. Bessai
This is the third post in a series about the Great Acceleration as a framework and reconnaissance for Canadian environmental history. The posts in this series are cross-posted with NiCHE.
Lake Diefenbaker concentrates the Great Acceleration within one prairie watershed. It shows how postwar Canada joined environmental transformation, settler state authority, hydraulic control, agricultural expansion, and the reordering of Indigenous sacred geography within one infrastructure system. Postwar governments accelerated production through large technical systems that reorganized environments and extended administrative control over land and water.1 Under a 1958 federal-provincial agreement, the Government of Canada and the Government of Saskatchewan advanced the South Saskatchewan River Project. Between 1958 and 1967, its main works, Gardiner Dam and Qu’Appelle River Dam, created a 225-kilometre reservoir, fixed the reservoir’s full supply level at 556.87 metres, and established storage of about 9.4 million cubic decametres of water. These dimensions mark a major transformation in the environmental history of the Canadian Prairies.2
Gardiner Dam gave that transformation its physical form. The dam stands 64 metres high and 5,000 metres long and remains one of the largest earthfill dams in the world. Its construction brought the South Saskatchewan River valley under a new regime of storage, release, and control. Seasonal flow became retained volume, scheduled discharge, and regulated supply. The South Saskatchewan River entered a system designed to stabilize production, expand irrigation, and support long-range settlement and development. Hydraulic engineering operated here as a large instrument of postwar environmental change. In Great Acceleration terms, Gardiner Dam converted a river system into a state-managed instrument of production, storage, settlement, and regional planning.3


