Environment Canada issued a special weather statement Sunday for areas around Calgary, Airdrie, Canmore and Crowsnest Pass, warning of significant rainfall.
The weather agency said significant rainfall is expected this week, with 75 to 100 mm expected by Wednesday morning.
“A long-duration rainfall event will impact the eastern slopes of the Rockies on Monday and Tuesday,” Environment Canada said. “A broad area from Nordegg to Waterton is expected to see at least 50 mm by Wednesday morning, with 100 mm or more possible in some regions of the foothills.
“Currently it appears as though the greatest rainfall amounts will be near Kananaskis, west of Calgary.”
Global Calgary weather specialist Jodi Hughes points out that June is Calgary’s wettest month, and typically, about 94 mm of rain is expected over the 30 days. If forecast conditions remain the same, the models suggest areas west of Calgary could see a lot of that amount in the span of just several days.
“There is a chance we could see some flooding and issues from this amount of rain in such a short period of time,” Hughes explained. “It is hard for the ground to rapidly absorb all of that at the same rate it is coming in.”
There is a High Streamflow Advisory in place in the Bow River Basin near Banff and in the Oldman River Basin.
According to Michael Drescher with the University of Waterloo, there are a number of things that people can do to protect their homes from flood damage, including buying add-on flood protection with your home insurance, adding covers to prevent water from rushing in through basement window wells, adding foundation grading to direct surface water away from the house, or installing a sump pump or sewer backflow prevention system.
Homeowners can also install on-site water storage to collect and store rainwater for a safe release later or install rain gardens, which are designed depressions with plants for increased water infiltration.
Boat advisory issued for Calgary
In response to the significant rainfall forecast for the area, the City of Calgary issued a boating advisory Sunday for the Elbow River.
No flooding over the riverbanks is expected, officials said, however, “flow rates are expected to increase, making conditions on and near the river dangerous. Water temperature remains cold and with the higher flow rates, water turbidity is increased, making hazards difficult to see.”
The city said extra precautions have also been taken due to the expected rainfall, including lowering water levels at upstream reservoirs on the Bow River and at the Glenmore Reservoir, to make room for additional flood waters.
Pathways in lower areas are also being closed, along with stormwater outfalls at several locations.
“The city has materials stockpiled and ready for riverbank protection and temporary barriers should they need to be installed,” the release stated.
The city is suggesting residents who live in low-lying areas to take certain precautions, including moving valuables and documents out of the basement, ensuring sump pumps or backflow valves are working, and directing rainwater away from the house.
Residents who live close to a river are urged to exercise caution and keep their children and pets away from fast-moving water.