REGINA ‑ A Water Security Agency (WSA) update to its spring runoff report is highlighting higher than expected runoff, which is helping to refill many of the reservoirs that were low following last summer's extended period of high heat and little precipitation.
The runoff began in mid-March in the southwest corner of the province and is progressing eastwards and northwards. A slower melting period with below freezing temperatures at night and cool daytime temperatures is helping keep runoff in channels with a low risk for flooding expected.
Higher than expected runoff in the Moose Jaw, Swift Current and Old Wives' basins has helped replenish water supply reservoirs. Runoff in the Maple Creek, Battle, Frenchman and Lodge Creek basins, while below normal, is higher than expected, but the Bigstick Basin is still below normal.
On the Qu'Appelle system, ice in the channel is causing higher than expected water levels throughout the system. Ice jamming remains a possibility and WSA continues to monitor this situation. Diversions into Last Mountain Lake are challenging due to the ice and some flow is being passed downstream on the Qu'Appelle River to prevent flooding upstream of Craven. With the exception of Last Mountain Lake, WSA expects all the lakes in the Qu'Appelle system to reach desirable summer levels.
While the slow melt is reducing the runoff potential in areas where there is snow, a rapid melt could produce higher than expected runoff in some areas.
With still higher than normal alpine snowpack, WSA expects strong flows along the South Saskatchewan River and will help bring levels at Lake Diefenbaker up to desirable levels for summer, improving conditions for irrigation, recreation and hydro generation.
Further north, spring melt and runoff are in the early stages and WSA does not expect significant changes to the March forecast unless conditions change dramatically due to rapidly warmer temperatures.
WSA will continue to monitor spring runoff as it occurs and provide updates as conditions change.