Hundreds ordered to evacuate as Assiniboine River rages

WINNIPEG – The Manitoba government declared a state of emergency Monday as flood waters from the Assiniboine River threatened the city of Portage la Prairie, 80 kilometres west of Winnipeg, and the surrounding rural municipalities of Portage, Woodlands, Rosser, St. Francois Xavier, Headingley, Cartier, Macdonald and Grey.

It came as the City of Brandon ordered the occupants of hundreds of homes to evacuate by Monday night and members of the Canadian Forces were deployed to shore up dikes, fill sandbags and perform other efforts to contain the surging river.

In Brandon, the cautionary evacuation order affects about 900 households in low-lying areas of Manitoba’s second-largest city. Local police went door-to-door in the area known as "The Flats" informing residents they have to leave by 8 p.m.

Brandon Mayor Shari Decter Hirst said Monday that while the evacuation is mandatory, it is being done out of caution. She said residents in that part of Brandon knew this was coming and the evacuation is expected to be orderly.

Meanwhile, provincial flood officials were to decide Monday night how to prevent uncontrolled flooding east of Portage la Prairie.

Emergency Measures Minister Steve Ashton refused to say if the province plans to carve out controlled breaks in dikes on the north side of the river.

Flow along the Assiniboine River at the Portage reservoir is expected to reach 52,000 cubic feet per second on or around May 11 and may reach 56,000 cfs by May 15, Ashton said.

This high flow is due to much higher than forecast flows from Saskatchewan and an "unstable weather system" that could bring 20 to 40 mm of rain across much of southern Manitoba between now and Wednesday.

The Portage Diversion, which diverts Assiniboine River water to Lake Manitoba, can only siphon off 25,000 cfs of water. The river channel itself can only take 18,000 cfs – and that’s only after this spring’s improvements.

The province is looking at ways to increase the flow of water through the Portage Diversion in the next few days. Even then, officials said, the river is likely to overflow its banks.

The city of Winnipeg is not threatened, officials said.

Ashton said that flood forecasting is a difficult task when you’re dealing with unprecedented water flows such as the ones hitting Manitoba.

On May 4, the province was predicting a crest of 26,000 cfs in Brandon. By late Sunday, the Assiniboine reached 38,000 cfs in Brandon – and the crest has yet to arrive.