Calgary city officials issued river safety advisories on Monday for the Bow and Elbow rivers after continuous rainfall and rising water levels over the weekend. Officials say flow rates exceeded recommended safety levels for boating, floating and swimming, and those levels are expected to remain high through Canada Day and potentially into the end of the week. The city says there is no risk of widespread overbank flooding, but localized flooding remains possible. The advisories come after weekend rainfall was driven by a stationary low-pressure system that brought significant moisture into the region and intensified precipitation across the Bow and Elbow basins. “Through yesterday, a stationary low pressure system kind of settled on the southeast corner of the province that drew a great deal of moisture in from the central continental United States,” Frank Frigo, manager of environmental management with the city’s Environmental Risk and Resilience Business Unit, told reporters on Monday. “It took a lot of that moisture and wrapped it around back onto the front ranges of our beautiful Rocky Mountains,” he said. That moisture brought up to 150 millimetres down on the city in less than 24 hours. Frigo says that rainfall led to rapid run-off and elevated river levels. Springbank Off-stream Reservoir used for first time Frigo told reporters flood mitigation infrastructure helped managed the impact of heavy rainfall — including the first ever use of the Springbank Off-stream Reservoir. The reservoir was built west of Calgary in the aftermath of the 2013 floods that devastated the city. Construction on the project, which cost about $850 million to build and holds four times the storage volume of the Glenmore Reservoir, finished last year. Water from the Elbow River was diverted into the reservoir in the early morning hours on Monday. “If this event had occurred and Springbank wasn’t in place, we would have been able to use the Glenmore Reservoir by itself, but we would have had to fill it right to the top and run the risk that we could have had some overspill,” Frigo said. “The criteria for operation of Springbank were surpassed by about 50 cubic metres per second, and that’s why its use was invoked, certainly made it much easier.” Calgary Mayor Jeromy Farkas called the Springbank Reservoir a gamechanger. “It really proves the foresight of those decision makers coming out of 2013 to address this issue once and for all,” Farkas said. Frigo said he’s confident the Springbank will keep water levels below the damage threshold, but there’s still risks for other kinds of damage, including erosion damage. He also warned residents about property-level impacts. “We’re also trying to ensure that Calgary, and particularly with properties in lower lying areas, are cognizant of the potential for basement seepage because of the elevated water levels,” he said. Frigo said precipitation is expected to taper in the short term but remain unstable through the week. “We’re likely to see 10 to 20 millimetres, relatively modest rainfalls during most of the days, for about the next seven days.” Fire department urging residents to keep away from rivers The Calgary Fire Department is also urging residents to stay away from rivers due to fast-moving water, debris and cold conditions. “There’s just a lot more risk associated with the activities, which is why we’re closely monitoring,” said fire department public information officer Alex Kwan. “We want to make sure that people can enjoy these activities safely, and that’s where we’re working closely with the city’s environment risk and resilience team.” Kwan added that conditions remain unsafe for recreation. “As it stands right now, we’re asking people to reschedule those activities just to make sure it’s a lot safer before you do any of those,” Kwan said.
