Conditions prompting risk of “moderate to major” overland flooding across Manitoba: infrastructure minister

Normal to well-above normal soil moisture and winter precipitation to date, combined with future unfavourable weather conditions, will result in the risk of moderate to major overland flooding across the province of Manitoba, the provincial infrastructure minister said earlier this week.

Infrastructure Minister Blaine Pedersen (L) and Doug McMahon, assistant deputy minister, water management and structures division, Manitoba Infrastructure (R) outline points from the 2017 January Conditions Report. Credit: Manitoba Infrastructure.

“We have experienced some unusual winter weather to this point that has contributed to an expanded risk of overland flooding in Manitoba,” Manitoba Infrastructure Minister Blaine Pedersen said in a press release. “At this time, we need to be aware of the potential for flooding with the understanding that we have a couple more months of winter weather and the uncertainty of the spring melt rate. The Manitoba Hydrologic Forecast Centre will continue to assess data over the coming weeks to refine future flood outlooks.”

On Jan. 30, Pedersen released the 2017 January Conditions Report due to the high soil moisture and winter precipitation to date, said the release from Manitoba Infrastructure, noting that the potential for overland flooding is estimated as moderate to major in most areas of the province. The report also noted this could change depending on weather conditions between now and the spring melt, with February and March flood outlooks further defining the flood potential.

The province’s practice is to plan and prepare for unfavourable weather conditions and the scenario of highest flood risk, the minister said.  At this time, with future unfavourable weather conditions:

• the Red, Souris, Pembina, Lower Assiniboine and Roseau rivers and the southwest region of the province are currently at risk for major flooding;
• the Upper Assiniboine River, eastern region, Winnipeg River, northern Manitoba and The Pas regions, including the Saskatchewan, Carrot and Swan rivers, are currently at risk for moderate to major flooding, and;
• the Interlake region and the Fisher River are currently at risk for moderate flooding.

The release noted that flood forecasters look at six primary factors when assessing long-term prospects for potential spring floods. In addition to soil moisture at freeze-up, other factors yet to be determined are: winter snow, spring rain, how fast the snow melts, the depth of frost and river and lake levels prior to spring run-off.

The Manitoba government and municipalities are continuing to prepare for spring flooding, Manitoba Infrastructure noted. This includes working with municipal emergency management teams to review existing emergency response plans and sharing information through conference calls and flood information seminars in Morris, Brandon and Selkirk.

The first full flood outlook is expected at the end of February.