Cold spring increasing the risk of flooding in Winnipeg
Manitoba flood officials say the prolonged cold spring is making flooding more likely for a few homes in Winnipeg.
The Red River is cresting upstream from the capital, but ice hasn't melted enough to open the floodway which diverts water around the city.
Emergency Measures Minister Steve Ashton said the amount of ice in the water is also pushing the river level up in south Winnipeg. A handful of low-lying homes may need ring dikes and other flood protection.
"We're able to operate the floodway in open water scenarios," he said at a flood briefing Wednesday.
"The ice on the Red River is, in many cases, three feet-plus thick still. I can testify, coming from northern Manitoba, that's probably the kind of thickness you would expect to see on our winter roads into remote, northern communities."
Grant Mohr, flood planning engineer with the City of Winnipeg, said three properties require about 2,300 sandbags.
"We continue to monitor river levels and will adjust our plans accordingly," he said in a statement.
The weather in Manitoba has been so cold — some 15 degrees colder than normal — that spring hasn't even arrived in many parts of the province. Steve Topping, the province's executive director of hydrologic forecasting and water management, said the spring thaw has been put on hold in many regions.
"We're in a deep freeze and the melt has basically abated. Run-off is declining on all our tributaries except for the Red River and the Assiniboine River," he said.
"In many parts of the province, the run-off hasn't even started. The snow pack still exists."
Icebreakers have been out to reduce the chance of ice jams and are ready to be deployed again in Winnipeg if necessary, Topping said.
But other than the prolonged cold, Ashton said officials aren't expecting any significant precipitation to exacerbate flooding.
The general flood risk is relatively low and officials aren't expecting to close Highway 75 this year — a key corridor to the United States which is frequently closed by flood waters.
"The cold weather, it's real, it's having an impact right here in the city of Winnipeg," Ashton said.
"The good news is warmer weather is on the way and we're still looking at very localized flood situations in the province. We're not looking at the generalized flood scenarios we saw either in 2009 or 2011."
Flood bulletin highlights
- Prolonged temperatures of as much as 15 degrees cooler than normal have prevented ice breakup on the Red River from Emerson to Winnipeg. The ice remains 10 to 20 per cent thicker than normal for this time of year.
- The Red River at Emerson is expected to peak on April 18 or 19 at a flow of approximately 35,000 cubic feet per second (cfs).
- The Red River upstream of the floodway inlet is expected to peak between April 20 and 22 at a flow of approximately 40,000 cfs.
- It is estimated with an open-water crest, levels at James Avenue in Winnipeg would reach 16.2 to 16.7 feet.
- Given the long-range temperature forecast, it is anticipated that ice along the Red River upstream of the floodway inlet and within the city of Winnipeg may still be intact when the Red River crests within the city.
- If it remains intact, the ice cover would induce a higher than normal crest producing a flow of 40,000 cfs. It is estimated the Red River water level at James Avenue could see an ice induced crest of 18.2 to 18.7 ft. with approximately 5,000 cfs spilling naturally into the floodway channel.
- Generally, 18 ft. at James Avenue is a signal to the city that a small number of low-lying properties may need additional flood protection.
- The Portage Diversion will continue to be operated to limit flows to 5,000 cfs along the lower Assiniboine River to minimize the risk of ice jams.