CALGARY’S MAYOR HAS warned that the worst of the flooding is yet to come after a significant portion of his city’s population spent the night pulling back to higher ground. Officials have estimated that as many as 100,000 could be out of their homes.

Entire neighbourhoods all along the Bow and Elbow rivers have been cleared of inhabitants as many downtown neighbourhoods were ordered evacuated in Calgary, a city of more than a million people that hosted the 1988 Winter Olympics.

Mayor Naheed Nenshi said early this morning he’s never seen the rivers that high or that fast.

Cars and homes are submerged in flood waters in High River, Alberta. Pic: AP Photo/The Canadian Press, Jeff McIntosh

Low-lying areas along the river started to flood last night and there was water filling up some underpasses. There was water in the streets of the Bowness area in the city’s northwest. The city has not said to what extent any homes have been flooded.

Police urged people to stay away from downtown and not go to work. All schools — both Catholic and public — are closed, while Catholic schools in the communities of Chestermere, Airdrie and Cochrane were also to be shuttered.

The Calgary Zoo, located on St George’s Island, closed its gates and started taking steps “to secure and move animals to safe locations.”

Contingency plans called for big cats, such as lions and tigers, to be moved into prisoner cells at the Calgary courthouse. But the city said that hadn’t happened yet.

The Calgary mayor spent Thursday night and this morning hours touring all the affected areas. He said it appeared that the smaller Elbow river had reached its peak. The same could not be said for the larger Bow.

The province reported that 12 communities were under states of emergency.

A helicopter carrying evacuated residents lands on a road in High River. Pic: AP Photo/The Canadian Press, Jeff McIntosh

It had been a rainy week throughout much of Alberta, but on Thursday the Bow River Basin was battered with up to 4 inches of rain. Environment Canada’s forecast calls for more rain today in the area, but in much smaller amounts.

Calgary is not alone in its weather-related woes. There were flashpoints of chaos from Banff and Canmore and Crowsnest Pass in the Rockies and south to Lethbridge.

Torrential rains and widespread flooding throughout southern Alberta have also forced the closure of the Trans-Canada Highway and isolated the mountain resort towns of Banff and Canmore. The flooding washed out roads and bridges, left at least one person missing and caused cars, couches and refrigerators to float away.

Officials in High River estimated half of the people in its town have experienced flooding in their homes. People had to be rescued from some rooftops by boat or in buckets of heavy machinery. Others swam for their lives from stranded cars.

The Royal Canadian Mounted Police called in the military, which sent two helicopters and a Hercules aircraft to help rescue those stranded in areas where roads had been washed out.

Kevan Yaets swims after his cat Momo to safety as the flood waters sweep him downstream after submerging his truck in High River, Alberta. Pic: AP Photo/The Canadian Press, Jordan Verlage

Pictures from inside the mountain town of Canmore also a raging river ripping at the foundations of homes.

Bruce Burrell, director of the Calgary Emergency Management Agency, said water levels on the Bow River aren’t expected to subside until Saturday afternoon.

Depending on the extent of flooding we experience overnight, there may be areas of the city where people are not going to be able to get into until the weekend.