Saskatoon river

Release of water from the Gardiner Dam today expected to match volume and flow of release in late May. (CBC)

The South Saskatchewan River will rise by about 1.5 metres downstream from the Gardiner Dam, the Water Security Agency announced Tuesday.

It's more than doubling outflows from 380 to 900 cubic metres per second (m3/s), due to heavy rainfall in southern Alberta.

The levels and flows are similar to the release in late May. 

"We're in a spot right now where with any forecast there's some uncertainty as to really the depth or the extent of the precipitation that we're going to see happen in Alberta," said the agency's spokesperson Patrick Boyle. So there could be further increases coming out of Gardiner Dam, he continued.

In the latter half of May the Agency lowered the level on Lake Diefenbaker, the reservoir on the South Saskatchewan River, by 0.8 metres.

"That gave us the ability to increase our storage for flood protection, should a rainfall event like this occur," Boyle explained.

People upstream from dam should beware

As for potential flooding along the South Saskatchewan, Doyle advised people upstream from the dam to beware.

"It's more agricultural impacts into the land in that region between the border of the province where the South Saskatchewan River comes in up to Gardiner Dam," Boyle commented.

However he also did not discount potential flooding downstream, between the dam and Saskatoon, adding that ferries will also need to beware.

In the city of Saskatoon, the Meewasin Valley Authority said right now the river is flowing at 500 m3/s, whereas the normal flow is 150 m3/s.

It's expected to peak at 900 m3/s, enough to flood boat piers, but nothing else.

The MVA is asking novice boaters are being asked to stay off the more swiftly flowing river.

No concerns downstream from Saskatoon

Downstream from Saskatoon, the Water Security Agency said flows will be above normal for this time of year but not expected to cause any flooding issues.

Levels in the section below Tobin Reservoir will rise about 0.6 metres above the current level, similar to levels in late May.

The Codette and Tobin reservoirs will fluctuate within their normal operating range.

The forecast for stream flows and any other relevant updates will be posted on the Agency's website at wsask.ca