A look at Edmonton’s plan to curb future flooding

A 20-year flood mitigation strategy is Edmonton’s proactive attempt at curbing the impacts of extreme precipitation events such as the one that hit the city on the weekend and flooded roads, sidewalks and recreation facilities.

A look at Edmonton’s plan to curb future flooding Edmonton and Epcor in 6th year of 20-year, $1.6-billion flood mitigation plan A 20-year flood mitigation strategy is Edmonton’s proactive attempt at curbing the impacts of extreme precipitation events such as the one that hit the city on the weekend and flooded roads, sidewalks and recreation facilities. The city and utility provider Epcor are in the sixth year of their $1.6-billion Stormwater Integrated Resource Plan, which aims to improve Edmonton’s drainage system to slow and move storm water away from high-risk areas.

Ward Métis Coun. Ashley Salvador spoke about the massive program. “These types of extreme weather events are becoming more common,” she said in an interview Monday.

“It makes me think about how important it is to be proactive with the kind of infrastructure that we're building so that we're able to adapt and mitigate those impacts as best as we can.” According to Epcor’s website, the strategy includes installing dry ponds — green spaces that act as catch basins for excess stormwater; separating tunnels, trunks and sewers to increase the movement of storm water and reduce the risk of backups. The plan also involves adding physical infrastructure to mature neighbourhoods like concrete bump-outs beside sidewalks that have greenery and mulch, Salvador explained.

“So it allows for water to be absorbed and pooled in those locations [so] that it slowly filters into our system rather than, you know, pooling unexpectedly or causing localized flooding,” she said. On its website, Epcor notes Edmonton has experienced significant flooding caused by large rainfall storms in recent years. “The impacts of flooding to citizens, the environment, society and property are substantial,” the website says.

The utility also offers several programs to support customers in improving flood resilience, including the RainWise Stormwater Rebate Program, free flood prevention home inspections and the Backwater Valve Subsidy Program. Alireza Bayat, a University of Alberta professor and senior engineering research chair at the institution, said underground pipe and sewer infrastructure in general needs more attention in all jurisdictions. "These are critical infrastructure that require more frequent maintenance,” he told CBC News on Monday.

Although Bayat doesn’t know how old Edmonton's pipes are, he said age likely isn’t to blame for the weekend flooding. “The capacity of the network — I don't want to necessarily link that to the age and say, ‘Because we are not spending, then we are flooding.’” Even with new pipes, he said heavy rainfall can still lead to flooding.

Bayat said that while a severe storm like the one that unfolded over the weekend isn’t necessarily so surprising, replacing pipes and sewers takes time. "This type of infrastructure, you cannot go and change it overnight,” he said. Ongoing impacts City crews continue to clear downed trees and branches that fell on roadways, pathways and trails on Friday, the city said in a news release Monday.

The city said Edmonton Fire Rescue Services responded to a record-high volume of calls during and after the weekend storms. Several recreation facilities, golf courses and city attractions have since reopened after briefly closing due to flooding this weekend. The Peter Hemingway Aquatic Centre at the Coronation Park Sports and Recreation Centre and the main pool at the Grand Trunk Fitness and Leisure Centre are still closed, as is the Telus World of Science.

The city said it continues to assess damage from the storm and is not yet able to provide an estimated cost for the cleanup and repairs.