Risk of Minor Flooding Along Souris River This Spring

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The risk of minor flooding at various points along the Souris River in North Dakota this spring is slightly greater than normal, the National Weather Service said.

Allen Schlag, a Bismarck-based National Weather Service hydrologist, said there will be a lot of water moving through the system, but it will be one-twentieth of the amount that came through Minot in 2011.

“It isn’t the kind of stuff that will create flooding and mayhem in Minot, but it will get some attention,” Schlag told the Minot Daily News.

The flooding in the summer of 2011, which was caused by heavy spring snowmelt and rains, inflicted main-floor damage to more than 2,700 homes in the valley. An estimated 4,100 structures in Minot were damaged, from sheds to businesses.

The chance of reaching flood stage at Minot’s Broadway Bridge in 2013 is less than 10 percent, according to the latest Flood Potential Outlook for the Souris River Basin. Although, additional snowfall in the coming weeks could significantly alter future outlooks, and spring rain is another factor.

“We are a long way out, too far to be really firm with an understanding of what spring rains will be like,” Schlag said. “The spring flood risk is highly dependent upon rain storms this year, as it often is, but right now there is not enough snow to create problematic flooding.”

Surveys show that the heaviest snowpack in the Souris River drainage lies above two key capture points in Saskatchewan Rafferty Reservoir near Estevan and Alameda Reservoir near Oxbow. Moisture estimates in the Canadian snowpack range as high as 200 percent of normal, but most of that snowpack won’t drain into the Souris.

Rafferty and Alameda Dams are believed to have enough storage available to adequately handle expected runoff.

Lake Darling is the last of the reservoirs on the Souris above Minot, and its level is slightly below the Feb. 1 target level as assigned by the International Souris River Board.

Of greatest concern along the Souris is Willow Creek, which has a 70 percent chance of reaching minor flood stage. The creek flows primarily south out of the Turtle Mountains and joins the Souris on the lower reach of river at the Upper Souris National Wildlife Refuge.

“There’s not a lot of potential for damage in North Dakota at this time,” Schlag said. “Some points along the river could reach minor flooding. It will be kind of a timing issue.”

The next Flood Potential Outlook for the Souris River Basin is due March 7.