At least one Prairie province has found temporary reprieve from the widespread flooding affecting the region, while emergency officials elsewhere are vigilantly monitoring surging water that has spread to a record extent.

The colder weather in Saskatchewan is slowing the spring thaw, and the province's Watershed Authority says that will balance out the blanket of snow on parts of the Prairies that threatens to bring reams more water into creeks and streams when it melts.

Authority spokesman John Falhman said the drop in temperature will likely ease water flows until later this week.

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A restaurant in the town of Lumsden, north of Regina, was stricken by the deluge on Saturday. ((David Stobbe/Reuters))

Already, several Saskatchewan communities have declared states of emergency or are braced to do so.

Officials in the town of Lumsden, about 35 kilometres northwest of Regina, declared a local state of emergency to deal with surging rivers. Further east in the Qu'Appelle Valley, the Muscowpetung First Nation has moved a number of residents, mostly elderly, off the reserve because of flooding, and it was expected there would be a need to evacuate more homes over the weekend.

Rising floodwaters in the valley are threatening 12 other First Nations communities, and the Federation of Saskatchewan Indian Nations demanded more help. Red Earth First Nation declared a state of emergency Sunday as flooding restricted access to the main road about 280 kilometres northeast of Saskatoon. More than 250 people were evacuated to Saskatoon.

Manitoba

On Sunday afternoon, crews were reinforcing dikes along the Assiniboine River to prevent overland flooding caused by icejams. Additional flow from the Assiniboine was expected to raise the Red River level Monday in downtown Winnipeg for a short period of time.

Why is it flooding?

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CBC's Johanna Wagstaffe

CBC meteorologist Johanna Wagstaffe gives insight into the cause of flooding across Alberta, Saskatchewan and Manitoba:

"There are a few elements leading to the already busy season and the high peak forecast. Snowmelt is a big one: Parts of Alberta and Saskatchewan were above average for precipitation by almost double between November and early March. But in southern Manitoba, they were actually below seasonal [precipitation levels] from November to March. That would probably affect ice jams more, hence the increase in ice jam flooding in that area. Temperatures are the other factor. A cold winter has increased run-off with a frozen ground, and the warm spell that the Prairies have experienced over the weekend and early this week caused a lot of fast snowmelt. So the immediate consequence of the combination of precipitation and cold is overland flooding due to frozen ground and ditches in combination with fast snowmelt. The warm temperatures have also been quickly breaking up ice and causing serious ice jams. The concern over the next couple of weeks will be the actual crest of the rivers, and whether or not the ring dikes and sandbags can hold."

Dikes along the river's banks in Winnipeg are holding and can accommodate at least half a metre more water. Officials warn, however, that that the crest of the flood is still weeks away, with the harrowing possibility that both the Red and Assiniboine are on track to crest at the same time.

Experts think the Red River could reach up to 6.95 metres in downtown Winnipeg, its second-highest level in 160 years, surpassed only by the devastating 1997 floods. At that height, the city will have to install more dikes to protect buildings abutting the river.

On Sunday, a northbound section of Highway 75 — the main route between Winnipeg and North Dakota — was reduced to one lane of traffic due to floodwater on the shoulder. 

The Portage Diversion, which shunts water from the Assiniboine into Lake Manitoba before it can course through Winnipeg, is operating at full capacity.

"We have not seen diversion flows like that since the great flood of '76," said Steve Topping, executive director of infrastructure for Manitoba Water Stewardship.

Topping said the unprecedented span of this year's flooding — from The Pas in the north all the way down to the U.S. border, and from the Saskatchewan border in the west through eastern Manitoba — has been challenging. Eleven survey crews are monitoring ice jams, river levels and flood protection, he said. In a usual flood season, there's only three. 

More than 700 municipal roads and dozens of provincial highways are closed because of flooding, 26 regional municipalities have declared states of emergency and about 700 people have been forced from their homes, mainly on the Peguis First Nation about 150 kilometres north of Winnipeg.

"Road closures can occur quickly. Motorists are advised to be cautious and avoid driving on water-covered roads," said Chuck Sanderson, head of Manitoba's Emergency Measures Organization.

Alberta

The City of Medicine Hat remained under a state of emergency, but elsewhere in the province, flooding appeared to be subsiding. Officials are still concerned, however, about the snowpack in the Cypress Hills border region with Saskatchewan. The snow has barely begun to melt, and could carry torrents of water into the area's waterways.


The risk levels displayed on the map are based on spring run-off potential. Other factors can alter that flood risk level. (CBC)

With files from The Canadian Press