Early forecast says Brandon at risk of 'moderate' flooding

Regardless of the weather experienced in the region, the City of Brandon is preparing for a high risk of moderate flooding, which was been forecasted by the province last week. The city's Risk and Emergency Management director says they're comfortable with preparations.

Early forecasts from the Manitoba's Department of Infrastructure show variable risks of flooding from spring runoff throughout the province, but this year's extended winter has made it too early to an accurate guess on what danger is posed by the Assiniboine River in Brandon.

In a Feb. 28 media release outlining this year's potential runoff rates, the Manitoba Infrastructure Hydrolic Forecast Centre suggested that there is a high risk of moderate flooding associated with the Assiniboine, Souris and Saskatchewan River systems. Should the Westman region receive favorable weather, water levels are expected to be less than 2015 levels along waterways from the Shellmouth River-Roblin, Man. area to Brandon. Normal weather conditions pose the same flooding threat, but with water levels potentially being less than 2014 levels.

However, should the spring rain fall at a higher level, and the runoff be hastened by a quick swing in the temperature, the Hydrolic Forecast Centre suggested levels could get slightly higher than 2014.

There is little danger posed by an influx of water coming into the Assiniboine River from Saskatchewan's Qu'Appelle River system. Water levels on the Qu'Appelle River and its chain of lakes and precipitation levels were well-below normal when Saskatchewan's Water Security Agency released their forecast three weeks ago.

Regardless, Brandon's Risk and Emergency Management Director Brian Kayes says flood mitigation work accomplished since 2011 has the city prepared for what, at this point, is estimated as “moderate” flooding levels.

“It's my job to be concerned and there is a certain level of concern, but we're watching what's going on closely,” Kayes said. “I'd have to say we're very comfortable with where we stand after raising the dykes and implementing water control measures over the past few years.”

This year's extended cold-weather period through the month of February and into March does pose the chance of a sudden melt, which could increase the threat of flooding. Should the temperature spike above the freezing mark over a short period of time, Kayes says the permafrost still in the ground will not allow the runoff to soak into the soil, forcing it to move overland.

“It is also dependent on how much more snow we get during the extended winter,” he said. “It all adds up, but we're preparing for the spring as we ordinarily do.”

Like the Assiniboine, the Souris River watershed is expected to see moderate flooding this spring. There were average rainfalls in southern Saskatchewan last summer, leaving soil moisture conditions at just above average at freeze up. Estimated visual snowpack levels showed an increase of precipitation in February, but Sask.'s Water Security Agency says a low projected runoff suggest no flooding for Grant Devine Lake or the Rafferty Reservoir, therefore no need to draw down these Souris River Basin waterbodies.

South-central Manitobans and Winnipegers are bracing for what is expected to be major flooding along the Red River, however.

Should the province experience average weather through the early part of spring, water levels along that system may reach 2011 levels, putting farmland and some roadways at risk. The situation will intensify should the region experience a sudden melt, high spring precipitation rates or ice jams from thicker-than-average ice levels on the Red River.

Updated flood forecasts are scheduled to be released by Manitoba's Hydrolic Forecast Centre in the coming weeks.

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