Edmonton mulls accelerating $1.6B storm-water plan after record summer floods damage dozens of homes

Edmonton's summer of record rainfalls — more than 500 mm in June and July, the highest volume in decades — has prompted city-owned utility EPCOR to consider accelerating work on a 20-year, $1.6-billion storm-water resilience plan launched in 2019.

The extreme weather exposed weaknesses in the city's aging storm-water network. Major roads including Whitemud Drive, Yellowhead Trail, Groat Road and the Connors Road-Low Level Bridge interchange turned into rivers and lakes. Scores of homes sustained water damage from sewage backups or overland flooding.

Multiple storms a week left the groundwater table so saturated it stopped absorbing, sending more runoff than normal into the storm-water system, which then struggled to keep up. EPCOR said a lengthy stretch of dry weather was needed to allow the system to recover.

Mayor Andrew Knack acknowledged Monday that flood resiliency should have started decades earlier. "What used to be one-in-100-year floods are now more like one-in-10-year floods," he said. "A lot of our infrastructure held up the way we had envisioned it to. Obviously there's still more work to do. Not every area held up the way we wanted it."

Craig Bonneville, vice-president of planning, projects and engineering at EPCOR, said the city will examine its infrastructure in problem areas. "We're going to look closely at our infrastructure and those cases, and see how over time we can make improvements to help mitigate those risks," he said.

The July storms took a particularly heavy toll on northwest Edmonton neighbourhoods. Horseshoe Creek overflowed, eroding banks around its culvert and causing a 137-metre stretch of 137 Avenue to crumble into a deep trench. The road remains closed, limiting access to the Big Lake area. Residents say erosion concerns were raised years ago, and many were already waiting for EPCOR to expand the creek's culvert to improve drainage.

Raf Tenderenda with the Big Lake Community League said the utility failed to act. "As a utility ratepayer, you assume Epcor will step up and do the right thing — and in my opinion, they didn't do that," he said.

City councillor Keren Tang noted that accelerating the plan involves balancing financial and community impact. "If we want to implement all in one go, there's huge financial, huge community impact that we have to keep in mind," she said. The plan is now in its seventh year.