June 1 Water Supply Conditions Update

Following last year’s drier-than-normal conditions, and improvements overall to moisture levels across much of the province, conditions have generally improved; however, many parts of the province are still below normal.

Precipitation over the winter ranged from below normal in the far south to above normal in the north. Heavy precipitation this spring across much of the eastern portion of the province resulted in additional runoff, with many streams and rivers in the Assiniboine, Pipestone, Red Deer, Souris, and Swan river basins recording above normal peak flows. The rainfall runoff in eastern areas has helped fill lakes and reservoirs, leaving most at or above normal summer levels. The rain has also left the soil conditions wetter than normal, making these areas more responsive to rainfall events.

In the west, with the dry fall and below normal runoff this spring, soil moisture conditions are generally drier than normal. Most of this area is experiencing drought conditions that range from moderate to severe. Late winter precipitation helped many of the lakes and reservoirs across much of southwestern Saskatchewan fill to near normal levels. The exceptions are the reservoirs in the Big Stick Basin near Maple Creek, which are generally below normal. Rafferty and Cookson reservoirs also did not fill.

In the north, snowmelt runoff over much of the Churchill River and Lake Athabasca areas is near completion. Observed peaks were generally near to above normal. Flows are generally above normal due to higher-than-normal winter flows and spring precipitation.

Inflows into Lake Diefenbaker on the South Saskatchewan River are currently well below normal for this time of year. Though recent heavy precipitation events in Alberta will likely have significant impacts. The snowpack in the alpine region of the basin is also above normal; however, with dry conditions across the prairie portion of Alberta, diversions have been high resulting in the low inflows into the reservoir. The current operating plan for Gardiner Dam is to manage outflows to help refill the reservoir.

Flows on the North Saskatchewan River and the Saskatchewan River are also below normal. Although the remaining snowpack in the alpine region of the headwaters is near normal, flows on the North Saskatchewan River are expected to be slightly below normal as both Lake Abraham and the Brazeau Reservoir in the headwaters are currently at below normal levels. Flows on the Saskatchewan River are also expected to remain at below normal levels.

This report is current as of June 1, 2022; however, weather events in headwater basins in Alberta have changed the expected outcomes. WSA will provide updates on these forecasted impacts as they develop and conditions change.