River flows to stabilize by end of week: Water Security Agency

The South Saskatchewan River has peaked after the opening of the Gardiner Dam last week, and the spillway has once again closed.

Patrick Boyle, spokesperson for the Water Security Agency in Saskatchewan, said the river is working its way through its peak presently, after seeing its high flows of 700 cubic metres reach Saskatoon around June 14.

Read more:

• Meewasin Valley Authority temporarily closes beach sites near Saskatoon
• Increased flows prompt calls for caution near South Sask. River in coming days
• Water agency urges caution around South Sask. River ahead of Lake Diefenbaker release

Throughout Tuesday and the rest of the week, Boyle said the high flow event will continue to slow down.

Boyle said the spillway closed on Mon, June 15, and said he expects river levels to stabilize in Saskatoon within a day or two, roughly around June 17.

The Water Security Agency is planning to hold river levels around 270 cubic metres per second through June 21.

“There is some rainfall predicted in Alberta, in the foothills,” Boyle explained, “so we’re going to look at some of those forecasts and things. So we’re kind of looking at about five days out right now, and then we’ll sort of look at where things will line up.”

The long-range forecast depends on Lake Diefenbaker, which is tracking at around-normal levels or just above normal levels presently. Boyle said outflows will be dictated by current weather conditions and depend on inflows.

“If we see a lot of rainfall here in the spring and into summer, then outflows will have to increase,” Boyle shared.

That could mean reopening the Gardiner Dam again later this season, depending on how high water levels become from rain and other factors.

“It really just depends on kind of that weather situation going out,” Boyle said. “That mountain inflow is coming in and it was above normal, so we’re looking at that, but you know, we never close the door to that possibility, because if you get a pretty heavy or intense rainfall in sort of the Rocky Mountains, the foothills in Alberta … depending on how much rain, yeah, we would have to look at another operation.”

He said a second opening of the spillway is not being planned, however, at this time.

“We’re now assuming the normal conditions going forward, we’re kind of staging down and trying to meet our target for July 1 level,” he said. “That is kind of that balance of where everyone’s happy with a certain lake level at this time of year.”

The agency has a long-term idea of where the reservoir level will be, based on average conditions ahead this year. Boyle said conditions can vary from below average to above average, and so a “live or rotating forecast for the reservoir and outflows” is kept by the agency. While the South Saskatchewan River is regulated due to the Gardiner Dam and Lake Diefenbaker, the North Saskatchewan River does not have any structures until Tobin Lake.

“So what comes in flow there is coming no matter what,” Boyle said.

Those calculations are part science and part art, he shared. Managing Lake Diefenbaker, however, is a priority because it serves as the main drinking water supply for more than 60 per cent of the province and also supplies habitats, wetland projects, irrigation, power production and supports recreation as a multi-use reservoir.

At this time, the agency is reporting it is on target for July 1 – “which is where we want to be,” Boyle said – keeping the reservoir at about 555 metres of elevation.

“We look like we’re going to be probably pretty close to a normal level, maybe just above normal for the reservoir for this summer, but that again is all dependent on that rainfall situation,” he explained.

River safety emphasized by Saskatoon Fire Department

A media event on Tuesday at the Saskatoon Fire Department’s Fire Station 1 saw further warnings about river safety shared by the department’s battalion chief.

Assistant chief Dwayne Jobson told reporters that flow rates on the river now are still roughly four times faster than normal.

An incident on Monday, which required firefighters to rescue a boater in distress on the South Saskatchewan River, punctuated Jobson’s safety warnings.

Jobson said the flow in the Saskatoon area of the South Saskatchewan River peaked around 1 p.m. on June 13, according to the Water Security Agency, at around 722 cubic metres per second, which continued into June 15 around 9 a.m., when a slight decrease to 700 cubic metres per second was noted.

As of Tuesday at 1 p.m., the river was flowing at about 500 cubic metres per second, Jobson said.

“The inflows into Lake Diefenbaker are expected to decline gradually throughout the week, but the flow rate is still extremely high, and even at 500 (cubic metres per second) to give you an example, when the flow rate is at 450 cubic meters per second, we suspend our rescue dive operations,” Jobson shared.

“It’s too dangerous for us to put people in the water, and we’re still well above that flow rate. So we can still attempt surface rescues, but we can’t put anyone in the water because of the extreme hazard.”

Jobson recommended that people stay off the water, until flow rates further ease to what the new normal level is for the summer.

“Right now, it’s too risky. It’s not worth it.”

Within the next week, Jobson said the hope is to see the river return to somewhat normal levels for the season, between 250 and 300 cubic metres per second.

Jobson said despite the elevated flow, most people have done a good job of staying away from the water and being cautious along the shores, being “respectful with the risk the river poses right now.”

–with files from 650 CKOM’s Mia Holowaychuk