Heavy rains hammering southern Alberta caused mudslides and road closures, forced evacuations and swept a mobile home believed to have two people inside into a rain-swollen river on Thursday.
The house trailer collapsed into the Highwood River area near Black Diamond, south of Calgary.
Cam Heke of STARS air ambulance said crews conducted an aerial search of the area for 40 minutes before being forced to return to Calgary to refuel.
“STARS was requested to aid in a search-and-rescue effort after reports of two adults going missing following the capsizing of that trailer,” he said.
But STARS had several other emergencies and had to decide whether to go back south of Calgary or to another location near Rocky Mountain House for another medical emergency, Heke said.
“It’s all about triaging.”
The heavy rains created flashpoints of confusion.
Mudslides forced the closure of the Trans-Canada Highway around the scenic mountain towns of Banff and Canmore.
Several communities in the mountains and foothills declared states of emergency as rising rivers threatened roads and bridges.
The RCMP were warning of several mudslides on highways around Banff and in the popular recreation area of Kananaskis. Several sections or road were reported to be washed out.
“It’s a real mess,” Sgt. Patricia Neely said. “Not to make light — things are very fluid as to what is going to happen. It will take a little while before these roads are passable.”
Parks Canada spokeswoman Michelle Macullo said people caught inside the park didn’t really have many options.
“Right now, if people are in Canmore they can get to Banff. People from Banff can get to Canmore,” she said. “We just have to wait to see what the weather presents.”
Canmore spokeswoman Sally Caudill said motorists were trapped overnight Wednesday by water spilling over the Trans-Canada and had to be rescued by helicopter.
“We had about 20 or so people on the highway … who got stuck,” she said. “Water covered the highway in two places, so we used a helicopter to get those folks out.”
Caudill said Cougar Creek, which runs through her community, was rising quickly Thursday. The town’s website said the creek’s banks were unstable and dangerous.
“Cougar Creek is very serious and changing very quickly,” Caudill said. “Homes that back immediately onto the creek have been evacuated starting at about 3 this morning. We are now extending that evacuation.”
Watered threatened roads and homes and forced residents to flee in High River, Black Diamond and Turner Valley — communities along what is know as the Cowboy Trail in the foothills of the Rocky Mountains.
A mandatory evacuation was issued for several areas in High River as the Highwood River rose. The hospital was evacuated and residents of a seniors residence were told to leave.
High River Mounties were calling for help from residents with motorboats to help rescue at least a dozen people stranded in their homes.
“It’s bad,” said High River spokeswoman Joan Botkin.
“The most unnerving thing, I guess, is that river forecasters are predicting — if we receive another 40 millimetres of rain — the Highwood will crest at about 1,270 cubic metres a second between noon and early evening. We encounter flooding at around 210 cubic metres.”
Barry Williamson, a councillor in Turner Valley, said that community was in danger of being cut off as well. Traffic was being restricted on the two bridges out of town as water levels crept within a metre of the their decks. The third road out is in a flood-prone area.
Two small subdivisions, home to about 50 people, were being evacuated, he said.
“Go back to 2005, that was our 100-year flood here,” Williamson said. “This is looking to be higher than that in terms of the flow of the river and height of the rivers.”
In Calgary, heavy rainfall and lightning overnight Wednesday sparked power outages and flashing traffic signals in every area of the city. Crews were out Thursday trying to repair the damage.
The city declared a local state of emergency and said there was sandbagging in some locations as the Bow and Elbow rivers continued to rise.
In Turney Valley, the Alberta Energy Regulator reported flooding may have caused a sour gas leak near Turner Valley.
Spokeswoman Kim Blanchette said there were multiple reports of the leak, but details were sketchy.
An Alberta Emergency Alert was issued saying the rupture was potentially life-threatening and urged people to move indoors and prepare for a possible evacuation.
Sour gas is colourless, natural gas that smells like rotten eggs. It contains hydrogen sulphide and is extremely toxic even in small amounts.
Environment Canada issued a rainfall warning for the affected areas, estimating as much as 100 millimetres more rain could fall in the next two days.