Since Wednesday morning, 80 to 280 millimetres of precipitation have fallen in southern Alberta, with as much as 340 millimetres pelting the mountains and foothills from Edson, west of Edmonton, to Waterton Lakes National Park near the U.S. border. River levels dropped in many communities Sunday, including in Canmore and Lethbridge, but weather conditions are expected to remain unstable over the next few days. Scattered showers and isolated thundershowers are forecast for most of the province, as flood worries spread east and north of Calgary. In all, 25 Alberta communities were under a state of emergency Sunday afternoon in what is now officially the worst flooding in the province's history.
Where the floodwaters are headed:
Drumheller: The town of 8,000 people northeast of Calgary has asked about half of its residents to leave their homes and acute-care patients have been moved out of the local hospital. While the Red Deer River was not expected to crest until midnight, flooding had already affected a handful of homes and campgrounds Sunday morning. The river was expected to hit a peak flow of 1,370 cubic metres per second, similar to 2005. The world-renowned Royal Tyrrell Museum is not in the flood's path. The museum is on higher ground, far from the flood zone.
Medicine Hat: The eastern Alberta city of about 61,000 people is bracing for a potentially record-setting deluge. The South Saskatchewan River was expected to crest Monday around 7 a.m., reaching a peak flow of about 5,500 cubic metres per second. About 10,000 people have been asked to leave their homes. The last time the river was predicted to swell this high was in 1995.
Saskatchewan: The Water Security Agency is cautioning the public that record inflows from Alberta will cause flooding along the South Saskatchewan River in Saskatchewan. The South Saskatchewan River was expected to peak Monday, rising two metres and surging into Lake Diefenbaker at a flow of more than 6,000 cubic metres per second. This would be the highest flow ever recorded. Typically, the river flows around 500 cubic metres per second this time of year. Efforts are underway to move more than 2,000 people from the village of Cumberland House and the Cumberland House Cree Nation in northeast Saskatchewan. The communities are downstream of where the swollen North and South Saskatchewan Rivers meet.
Manitoba: An intense low-pressure system pushing north from North Dakota brought significant rain and thunderstorms to southwest Manitoba on Sunday. As much as 150 millimetres of precipitation was expected between Sunday and Monday, which could lead to flash or overland flooding in the northwest, Interlake and southwest regions, warned Manitoba's Hydrologic Forecast Centre. The Saskatchewan River in The Pas, meanwhile, was expected to swell to 2011 high levels as floodwater from Alberta moved east through Saskatchewan and into Manitoba. The river could crest in The Pas in eight to 12 days.
Compiled by Renata D'Aliesio