Manitoba downgrades threat of serious spring flooding

Manitoba has downgraded the threat of major spring flooding, despite receiving a significant amount of snow this winter.

The province said Friday it received updated high water conditions based on current weather conditions and flows in Manitoba and North Dakota.

“These new predictions are showing a downgrade and it refines last week’s forecast,” said Doyle Piwniuk, Manitoba’s infrastructure Minister.

Piwniuk said the updated data shows a flood more in line with 2017 conditions.

“While the updated reported shows more positive, we are still expecting to operate the Red River Floodway,” the minister said, noting the province is remaining vigilant in case of heavy spring precipitation.

Piwniuk said Manitoba snowfall amounts this winter are the third highest on record, with the highest accumulation occurring back in 1923.

Fisaha Unduche, the executive director of Manitoba’s hydrologic forecasting and water management operations, said some areas in the northwest and southwest parts of Manitoba received record amounts of snow.

“Most basins in Manitoba received over 80 centimetres of snow in the winter with some areas in southeast Manitoba, including the Whiteshell lakes area receiving over 160 centimetres of snow,” Unduche said.

“This snow accumulation is generally considered above normal for the winter season.

“Even though soil moisture heading into freeze-up was drier than normal the amount of snowfall could lead to significant surface runoff, depending on future weather conditions.”

In the March outlook, the province forecasted a high risk of major to moderate flooding.

But in the past two weeks the weather has been favourable.

“There has not been any significant precipitation and the temperatures have been staying near zero,” Unduche said. “These conditions are allowing for a very gradual melt, reducing the runoff as the water has time to get absorbed in the ground.”

The short-range weather forecast continues to indicate favourable weather, Unduche said.

“In other words, this is very good news because Mother Nature has been cooperating very favourably and that’s why we have downgraded our flood projections from our March outlook,” he said.

Unduche said the province expects the first peak on the Red River at Emerson between March 30 and April 2. He said the first peak is expected in Winnipeg by April 5.

He said a second peak in the Red River Valley is expected as a result of the snow melt between April 10 and April 20, with the second peak expected to occur in Winnipeg between April 12 to April 22.

Unduche said the updated forecast means there will be a risk of moderate flooding for the Red River, a low risk of spring flooding for the Assiniboine, Pembina and Souris River basins, and a risk of minor to moderate flooding in the eastern region, including the Roseau, Rat and Whiteshell Lake areas.

“Most Manitoba lakes are expected to remain within their desirable operating range after the spring runoff,” Unduche said.

He said the risk of flooding in the Interlake is low, but ice jam flooding remains a concern for the Icelandic and Fisher Rivers.