Calgarians may have been displeased to break out their boots and shovels over the long-weekend, but April snowstorms are strengthening Calgary’s water supply for the summer season.
According to Canada Weather Stats, Calgary has already recorded 18.6 centimetres of snow in April. That followed a heavy March with 47.8 cm, compared to 16.6 cm in February and 7.9 cm in January, signalling a late-season boost to snowpack levels across the region.
While snow dumps cause chaos for city traffic, Frank Frigo with the City of Calgary, said it’s critical for snowpacks that feed the city’s water supply. The City of Calgary’s manager of environmental management highlighted the dense snowpacks that have developed in the Rocky Mountains over the winter, which ensures plenty of water for agriculture and Stampede season.
“It often becomes difficult to supply all that water unless we have an ample alpine snowpack, so this is really wonderful for us in that regard,” he said.
“It really helps stave off the potential for early-season drought.”
Frigo said the snowpacks that feed the Bow and Elbow rivers are sitting at above-average levels, eclipsing summer peaks seen last year. Little Elbow Summit, which sits in the headwaters of the Elbow River southwest of Calgary, has already doubled last year’s numbers and is well above the average. According to The Weather Network, at this time last year, the summit was sitting at 250 millimeters, when averages are between 300-400 mm. Right now it’s at 531 mm.
“This is particularly potent and important for us in terms of water supply because that alpine snow tends to reflect the sun,” Frigo said.
“At higher elevations, it experiences colder temperatures, which means it hangs around longer in the summertime.”
These winter conditions, Frigo pointed out, were especially important during the Bearspaw feeder main repairs. According to Frigo, the Glenmore Reservoir generally provides 20 per cent of Calgary’s water demand during the winter, but when the first feed main went down, it was providing 80 per cent of the city’s drinking water.
Even with that strain, the steady inflow from winter snow and periodic melts helped maintain reservoir levels. According to provincial data, the Glenmore Reservoir currently sits at 78 per cent of its maximum storage, which is above the normal average. This is paving the way for the city to begin summer preparations.
“We’re actually actively now releasing a little bit of water carefully and slowly from the Glenmore Reservoir, anticipating the melt that’s going to be occurring as temperatures warm up heading into May,” Frigo said.
No concern for flooding right now
Despite the higher accumulation, Frigo said there is no immediate cause for concern for flooding. In fact, the large snowpacks give the city more wiggle room to be aggressive with reservoir levels to avoid flooding.
“It actually offers us a little more flexibility in terms of total water management in both the Bow and Elbow basin to be able to offset flood risk, because that snow melt mechanism is a lot slower than the rainfall runoff process,” he said.
Current river flow data reflects this stability. According to Alberta River Basins, as of April 8, the Bow River at Calgary is flowing at 54.10 cubic metres per second, while the Elbow River below Glenmore Dam sits at 9.94 m³/s. Both levels are well below flood risk markers.
According to The City of Calgary, potential for flooding in basements and streets typically begins when flows exceed 500 m³/s for the Bow River and 120 m³/s for the Elbow River.
Frigo said the highest flood risk period in Calgary typically runs from mid-May to mid-July, when snowmelt and rainfall can combine to drive up river levels, but that it’s pivotal to always stay aware and prepared.
“We’ve had a lot of advancement in Calgary around river flood resilience,” he said.
“But that’s the time when Calgarians need to stay informed and be thinking about measures that they can undertake to protect their safety, property, and their families.
