April 29, 2013
Recommendation for Immediate Operation of the Portage Diversion Received at 11 a.m. Today
Manitoba Infrastructure and Transportation advises there are imminent ice-jam related flood risks for the Rural Municipality of Cartier and the communities of St. François Xavier and Headingley along the Assiniboine River east of Portage la Prairie as a result of increased flows on the river.
The department states the immediate operation of the Portage Diversion is essential to draw down flows on the lower Assiniboine River to protect these communities.
There is currently significant ice cover on the Assiniboine River between the town of Portage la Prairie and the city of Winnipeg. Warm weather and a rapid melt over the weekend have increased flow rates on the river and the ice is beginning to move in large chunks. These conditions can quickly result in ice jams and water backup along tributaries in the RM of Cartier, St. François Xavier and Headingley.
At 11 a.m. this morning, senior hydrological officials advised the Portage Diversion must be operated as soon as possible to reduce flows on the lower Assiniboine River and prevent ice jamming. The Portage Diversion has been used to protect these communities from flood damage nearly every flood year since it was constructed.
The immediate operation of the diversion this morning has been prevented by demonstrators inside the diversion channel. The province urges demonstrators to leave the area immediately for their safety and the safety of those in at-risk communities.
The Manitoba Emergency Measures Organization has been in contact with these communities today to ensure they are prepared for the potential flood impacts of ice jamming.
The operation of the Portage Diversion will also assist in the operation of the Red River Floodway and reduce the severity of its impacts south of Winnipeg, in particular to the community of Ritchot.
Water from the Portage Diversion flows into Lake Manitoba. The lake is currently at 811.8 feet above sea level, which is the middle of its operating range and well below the long-term, historical average.
The Waterhen River will be the major contributor to levels on Lake Manitoba this year. Under the current flood outlook, it is estimated that flows to Lake Manitoba through the Portage Diversion could cause water levels on the lake to rise by approximately two inches.
The province has also stationed earth-moving equipment at the outlet of the emergency channel as a contingency should it be required in the event of extreme water levels on Lake Manitoba and Lake St. Martin. The channel successfully brought Lake Manitoba and Lake St. Martin into operating range in 2012.
In the case of a wind storm like the one that caused major damage around Lake Manitoba in 2011, geo-tube wave breakers are in place at locations at Delta Beach, Twin Lakes Beach and in the RM of St. Laurent at Sandpiper Beach.
Up-to-date flood information can be found at www.manitoba.ca/flooding, on mobile devices at www.manitoba.ca, on Twitter at www.twitter.com/MBGov or at 1-866-626-4862.
Up-to-date highway information is available at www.mb511.ca, on mobile devices at www.manitoba.ca, on Twitter at www.twitter.com/MBGovRoads or by calling 511.
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