Winnipeg prepares for spring flood on scale of second-worst in recent memory, purely as a precaution
City looking for outside help on sandbag dike construction; Province has yet to make a flood forecast
The City of Winnipeg is preparing for a flood nearly as severe as the second-worst deluge in modern history — even though there's no indication the Red River will rise that high next spring.
High soil moisture and high river volumes throughout the Red River drainage basin have increased the potential for a spring flood in 2020, although how high the river rises will depend more on winter snowfall, the moisture content of that snow and the weather during the spring melt.
Nonetheless, Winnipeg is poised to hire outside engineering help to survey and manage sandbag dikes for 290 low-lying properties in anticipation of a Red River flood crest as high as 22.5 feet above normal winter ice level at James Avenue.
That level is close to the crest of the 2009 Red River flood, which crested at 22.6 feet James, the second-highest peak since the Red River Floodway was completed in 1968.
Only the 1997 Flood of the Century was more severe. The city is preparing a flood as high as 2009, even though the province is not made any flood projection, as of yet.
"With current river elevations within the City of Winnipeg being higher the than average, the public works department is preparing for a flood event with river elevations based on a scenario of 22.5 feet James Avenue," reads a city request for proposals for engineering services.
"However, the scenario may increase or decrease depending on various factors," the document reads.
Forecasting factors
Flood forecasters take a number of factors into account, including soil moisture at freeze-up, river flows at freeze-up, the height of the snowpack on the ground, the moisture content of the snow, the depth of frost when spring rolls around and, most importantly, the weather during spring.
In 2019, a projection of a major spring flood fizzled into a minor one, thanks to cool and dry spring weather that facilitated a gradual and gentle snowmelt.
Winnipeg communications manager David Driedger said in spite of the wording in the city's request for proposals, the city is not predicting a 22.5-foot flood.
"It's a benchmark we use in our flood-planning scenarios," he said in a statement, explaining that a flood above 22.5 feet would require far more advance preparation.
"In short, we're doing our due diligence to ensure that we have the necessary engineering services on retainer should the need arise."
The consultants would oversee sandbag construction at 150 properties in the Kingston Crescent and Kingston Row area, plus another 140 on Scotia Street and Glenwood Crescent.
The province is still gathering information before it makes its first flood projection, said a spokesperson for flood forecasting centre.
In the United States, where the Red River has a smaller capacity and the snowpack is higher, officials are already concerned.
"We're certainly looking at a substantial flood. I would certainly say that we're in major flood," said Greg Gust, a forecaster with the U.S. National Weather Service in Grand Forks.
With files from Erin Brohman