The Saskatchewan Water Security Agency is warning of rising water levels on the South Saskatchewan River starting Sunday, June 7 [2].
The planned release is necessary to manage reservoir levels at Lake Diefenbaker. Because the increase in flow will significantly raise the waterline, residents and recreational users are urged to exercise caution near the riverbanks.
Officials will open the spillway at the Gardiner Dam to facilitate the release. Current river flow is approximately 280 cubic metres per second [1]. Following the release, the projected flow is expected to reach approximately 700 cubic metres per second [1].
The impact will be felt downstream, particularly in the Saskatoon stretch of the river. Experts expect the waterline in Saskatoon to rise by more than 0.5 metre [3]. This surge represents a substantial increase in the volume of water moving through the system, marking some of the highest levels seen in the region in six years [3].
The agency announced the preparations on Wednesday, June 5, to ensure the public has time to secure equipment and adjust activities near the water. The increase in flow is a controlled measure to maintain the safety and stability of the reservoir infrastructure [2].
Local authorities advise that the river will remain volatile as the spillway operations continue. The agency said the rise in levels is a planned event, but the speed of the current will increase as the volume of water moves toward Saskatoon [1].
“Water flows are expected to more than double following a planned release.”
The controlled release from Lake Diefenbaker demonstrates the critical role of the Gardiner Dam in regional flood mitigation and reservoir management. By intentionally increasing the flow from 280 to 700 cubic metres per second, the agency prevents uncontrolled overflows while managing the basin's capacity. The resulting rise in the Saskatoon waterline highlights the river's sensitivity to upstream dam operations and the necessity of early public warnings to prevent accidents during high-flow events.





