Canmore, Alta., has declared a local state of emergency because heavy rainfall made the banks of a creek that runs through the town unstable.

About 40 homes south of the pedestrian bridge over Cougar Creek were evacuated at 2 a.m. MT on Thursday, Canmore Mayor John Borrowman said.

"The situation is actually bad and getting worse," he said. "Now some of the smaller creeks are starting to flood."

A Canmore resident watches the rising Cougar Creek early Thursday morning. A Canmore resident watches the rising Cougar Creek early Thursday morning. (Courtesy John E. Marriott)

The evacuees were taken in at the town's civic centre and at two local hotels.

Other residents are being alerted to be ready to move if necessary.

Power is out at various locations throughout the town, officials said.

Both the Trans-Canada Highway and Highway 1A are closed to eastbound and westbound traffic at Cougar Creek.

"We do not advise travel this way," said Canmore RCMP Const. Jeff Jantz.

"Don't come."

Crews are using heavy machinery to try to redirect some of the water surging into the Bow River, he said.

Another 50 to 60 millimetres of rain is forecast in the area before the skies are expected to clear later on Friday.

Canmore is about 100 kilometres west of Calgary.

High River, Black Diamond

High River, about 70 kilometres south of Calgary, also declared a state of emergency early Thursday morning after the Highwood River started overflowing its banks.

Officials are encouraging residents in the Wallaceville area of town to leave their homes. Campers in George Lane Park have also been told to leave.

The town's emergency operations centre is open, and crews have been called in to begin sandbagging.

A flood warning has also been issued for Kananaskis Country west and south of Calgary, as the Sheep River threatens to burst its banks in the Okotoks area.

That river also flows through the towns of Turner Valley and Black Diamond, where some residents of low-lying areas are being told to leave their homes.

The Oilfields Arena in Black Diamond is being has been opened as a reception centre.

The hamlet of Bragg Creek, 44 km west of Calgary on the edge of K-Country, is also in a state of emergency as the Elbow River surges over its banks.

Officials in Calgary activated the city's municipal emergency plan late Thursday morning in anticipation of the heavy flows in the Elbow and Bow rivers reaching the city.

In southwest Alberta, parts of the Crowsnest Pass are being evacuated because of high water levels.

Some residents of Blairmore, about 240 km southwest of Calgary, are being asked to leave their homes.

A reception centre has been set up at the sports complex in the neighbouring community of Coleman.