WINNIPEG — Officials say Manitoba has been hit with so much rain and snow in recent months, there’s a possibility the Red River Valley will face a deluge big enough to force thousands of people from their homes and cause millions of dollars in damage.
There is a 1-10 chance that the river will rise as much as it did during the “flood of the century” in 1997 when 22,000 people were forced to flee towns such as Morris and St. Jean Baptiste on short notice, the government’s senior forecaster said Monday.
“High river flows, above-normal snow/water content in the snow pack and an expected cooler and wetter spring have increased the probabilities of significant flooding,” said Phillip Mutulu.
“Most of Manitoba does show … above-normal soil moisture conditions.”
Much depends on the weather between now and April. The size of the flood can vary depending on how quickly snow melts, how much precipitation falls in early spring and whether meltwater from North Dakota and Saskatchewan hits at the same time as the local melt happens.
But predictions suggest that even with average weather conditions, the Red River Valley will spill its banks the way it did in 2009 when it grew 16 kilometres wide in some parts. It swamped farmland, forced some towns to close all but one road to the outside world and washed out sections of the main highway between Winnipeg and the United States border.
Provincial officials promise they are ready.
“Each of the municipalities has an evacuation plan. They know how to exercise it and they have host communities that they have arrangements with already,” said Chuck Sanderson, executive director of the province’s Emergency Measures Organization.
Even Winnipeg, which is protected by the granddaddy of all flood-fighting tools — a 47-kilometre-long ditch that diverts water around the city’s east side — could be affected. There are a few dozen riverfront homes that will probably have to rely on sandbags or inflatable tubes to keep the river at bay. The high water could also overwhelm portions of the city’s sewage system and cause basement flooding in some homes.
Manitobans are used to flood talk almost every year, especially in the Red River Valley. It’s a natural flood plain, with water coming from the south and west. The region’s clay soil does not drain easily, and the river’s northward flow means melt water from the warmer south can rush up against solid ice near the mouth of the river north of Winnipeg. Most years, rural residents shrug at the flooding. They’re used to using boats to get around if need be.
This year’s expected deluge could test all of the improvements Manitoba has adopted since the 1997 flood.
All homes and business south of Winnipeg have been raised to at least 60 centimetres above the 1997 water level. Rural earth dikes and the Winnipeg floodway have been expanded. More machines have been purchased to break up ice jams and the government has acquired more tubes, sandbags and portable temporary bridges to prevent high water from spilling into buildings or cutting off communities.
“The reality is there will be some flooding … even under the best scenarios,” said Steve Ashton, minister responsible for the Emergency Measures Organization. “We’re not down to the point where in a few weeks, we’ll know where it comes in.”
Flooding is also expected along the Assiniboine and Souris rivers in western Manitoba. With unfavourable weather in the coming months, the area could see water levels not seen since the mid-1970s.
The one spot of good news is ice thickness which is less than normal because of a warm December and January. That reduces the chance of major ice jams. In 2009, giant chunks of ice pushing up against each other north of Winnipeg caused localized flooding. Some huge pieces crashed into homes.
