Calgarians are being warned about heavy rainfall and flooded roadways amid an Environment and Climate Change Canada (ECCC) rainfall warning.
An ECCC weather advisory issued Monday says Calgary can expect anywhere from 50 to 100 millimetres of rain, with rainfall amounts in excess of 100 millimetres possible in certain areas.
ECCC says rain in Calgary will become lighter starting Tuesday evening. The agency is warning drivers to watch for water pooling on roads and avoid driving through flooded roadways.
University of Saskatchewan hydrologist John Pomeroy says, while there’s still uncertainty around the rainfall, including how intense it will be and where it will land, it won’t reach levels seen in the 2013 Alberta flood.
“We’ll have high flows, but nothing like 2013,” Pomeroy told The Calgary Eyeopener Monday morning.
Pomeroy, who is based in Canmore, said in addition to the Bow River in Calgary, “very high flows” are starting to come through the Oldman River drainage basin near the U.S. border, and also up into the Battle River basin, between Calgary and Edmonton.
He said while current river flows are high for this time of year, with the Bow River in Calgary at 400 cubic metres per second compared to the normal flow rate of 150 cubic metres per second, this is significantly less than the flood year of 2013, when flow rates in the river were around 1,500 to 1,600 cubic metres per second.
“It’s a lot less than the flood stages at Calgary where we get a lot of damage,” he said.
The Calgary Fire Department has issued a boating advisory for the Bow River, meaning people should stay off the river until flow rates return to safer levels.
Calgary Mayor Jeromy Farkas said in a social media post Monday that the city is “continuing to monitor rainfall and river conditions 24/7.”
He said the Glenmore Reservoir in southwest Calgary has been lowered to accommodate the high Elbow River flows, and that storm-water crews are addressing drainage concerns throughout the city.
“We are communicating regularly with Environment and Climate Change Canada, Alberta River Forecast Centre, and TransAlta to share the best available information,” Farkas said. “Crews, equipment and materials are ready in case we need to respond.”
Is $1B enough to mitigate future floods in Calgary?
Frank Frigo, manager of environmental management with the City of Calgary, highlighted $1.3 billion in investment from the federal, provincial, and municipal governments for flood mitigation, as well as measures taken ahead of the current rainfall.
“One of the critical things that we’ve done ahead of this event is prepare the upstream reservoirs, to make sure we’ve got enough room to slow things down,” he said.
“And so on the Bow River, we’re expecting things to get a little higher, but not a great deal higher than what they are right now.”
Numerous closures are in place in Banff National Park due to high water levels and flooding.
Near the Banff townsite, the Fenland day-use area and surrounding trails, Marsh Loop Trail and the lower boardwalk of the Cave and Basin Trail are closed due to flooding.
The Pipestone River area in Lake Louise, and a section of the Bow River Trail between the bridge to the Lake Louise Campground and the south Bow River pedestrian bridge, have been closed by Parks Canada “to ensure visitor safety in areas affected by high water.”
Alberta Parks has closed the popular Three Sisters Campground near Canmore to all access due to flooding.
The Town of Canmore has issued a high stream-flow advisory for the Bow River and steep creeks, meaning people should stay away from embankments and be cautious around areas affected by high water levels.
