Water Security Agency advising public of peak flows in North and South Sask. Rivers

(Herald file photo)

The Water Security Agency (WSA) is warning the public of above normal stream flows in the North and South Saskatchewan Rivers.

For the North Saskatchewan River, the WSA expects water levels to rise similarly to how it was in mid-May, with a peak flow near 1,500 m3/s. The peak is anticipated to reach Prince Albert around July 10, the Battlefords July 7 and the Alberta and Saskatchewan border July 5.

“Residents living along these areas are advised that high flows pose a safety risk and high water levels could damage property and infrastructure over the coming days,” read a news release.

“All users are additionally advised to use caution around the watercourses within the basin as swift moving water can pose a hazard and to take steps to protect property where necessary.”

The WSA said these levels are the result of existing moisture levels and precipitation upstream.

The peak inflow is also expected to rise to about 1300 m3/s at Lake Diefenbaker around July 5. The rapidly increasing flows on the South Saskatchewan River are from high amounts of rain in southern Alberta earlier in the week.

Upstream of Lake Diefenbaker, water levels are expected to increase by 0.75 m, or 2.5 ft, on average from Thursday’s levels, with some locations seeing an increase of 1.2 m, or 4 feet.

The WSA began a spillway release on Thursday at Gardiner Dam, bringing total outflows to about 520 m3/s. It will continue to increase to 300 m3/s on Friday, for a total outflow of 720 m3/s.

The WSA said it anticipates having to increase the release to 500 m3/s on Monday for a total outflow of 900 m3/s depending on how the inflows recede.

A flow of 900 m3/s will be near channel capacity upstream of the City of Saskatoon in the Pike and Moon lake areas.

On average, the water levels are expected to increase by about 0.9 m, or 3 ft. throughout the system with an outflow of 900 m3/s. Some areas may see increases of 1.5 m, or 5 ft.

No overland flooding is expected. Water users are advised to move pumps and intakes and all are asked to stay clear of fast-moving water.

The WSA will be examining the combined effects of these high water levels on the North and South Saskatchewan River systems beyond the Saskatchewan Rivers Forks, which is where the North and South Saskatchewan Rivers merge.