Regina — Runoff from the melt of the April 19/20 snowfall event is having more of an impact on the Qu'Appelle River System than previously expected, according to the Water Security Agency.
Runoff from the system's two largest tributaries, the Moose Jaw River and Wascana Creek, are receding more slowly and contributing more volume than expected.
Smaller tributaries, such as Echo Creek, have seen a second peak due to this meltwater. This is resulting in flows higher and for a longer period than previously expected, and what would typically be observed during a snowmelt runoff event.
This will push water levels at Crooked Lake and Round Lake higher than previously expected.
Crooked Lake is expected to peak between 452.55 metres and 452.75 m, which would be 0.25 to 0.45 m higher than the peak observed in spring 2022. This would be 0.1 to 0.3 m higher than the current level.
Round Lake is expected to peak between 443.2 m and 443.4 m, which would also be 0.3 to 0.5 m higher than the 2022 peak and 0.2 to 0.4 m higher than the current level.
These peaks are expected early to middle of next week with Crooked Lake expected to peak earlier in the week. At the upper end of the range, the peaks would be similar to those experienced in April 2015 (about 0.1 m lower). These are one-in-10-year peak levels.
Pasqua and Echo lakes are near their peak levels now, and Mission and Katepwa lakes observed their peak earlier in May and are receding slowly.
Last Mountain Lake is also expected to peak slightly higher than previously expected with a peak of 490.55 to 490.65 m also anticipated early next week. This would be 0.25 to 0.35 m higher than the spring 2022 peak.
These peak flows and levels could result in localized flooding on agricultural lands.
