Southern Alberta is gearing up for a saturated weekend as Environment and Climate Change Canada warns of significant rainfall and dangerously high water levels in the Bow River.
Thunderstorms are expected Saturday night, with heavier precipitation continuing through Monday and into Tuesday. Temperatures will also drop as the wet system moves through the region.
"It's hard to say with certainty exactly where and exactly how much we will see there, but that risk is there for those regions," said Christy Climenhaga, a scientist with Environment and Climate Change Canada.
Calgary residents can expect between 50 to 75 millimetres of rain, while areas west of the city — including the Banff region — could receive upwards of 100 millimetres.
Rapid Snowmelt Compounds the Risk
The timing couldn't be more critical. Recent warm weather has already accelerated snowmelt in the high alpine regions, pushing the Bow River to dangerous levels. On Friday, the river in Banff was flowing at 300 cubic metres per second — more than double its normal springtime flow, according to John Pomeroy, director of the Global Water Futures Observatories at the University of Saskatchewan.
For perspective, during the devastating 2013 Alberta floods, the Bow River reached 430 cubic metres per second.
Authorities Issue Urgent Safety Warnings
A high stream-flow advisory is now in effect for the Bow River upstream of Banff down to Ghost Reservoir, roughly 50 kilometres west of Calgary. The RCMP warns that the combination of elevated water levels and incoming heavy rain could trigger "nuisance flooding" and potentially close trails in Banff National Park.
The Town of Canmore is urging extreme caution near the river, particularly for children and pets. Residents are warned to stay off embankments, and all boats have been advised to remain off the water.
In Calgary, the Fire Department issued an advisory Friday against any boating activity on both the Bow and Elbow rivers. The city is not anticipating major overbank flooding but acknowledges that localized flooding along the rivers is possible.
Several pathway sections have already been preemptively closed, including the Centre Street Bridge underpass along the Bow and the Elbow River pathway under Scollen Bridge on 25th Avenue S.W. More closures could be announced if water levels continue rising.
City Takes Preventive Steps
The City of Calgary has begun proactive measures to manage the situation. Frank Frigo, head of environmental management for the city, confirmed that water in the Glenmore Reservoir has been deliberately drawn down by approximately one metre to create additional storage capacity should river levels spike.
Albertans are urged to check local updates throughout the weekend and to exercise extreme caution around rivers and streams. Weather conditions and river levels can change rapidly, and officials emphasize that safety near waterways should remain the top priority.
This story is based on reporting from CBC Edmonton. For the latest updates, visit the Environment and Climate Change Canada website or contact local emergency services.