Overtaxed drainage system slows drive after big storm
Flash flooding on Yellowhead Trail slowed traffic to a crawl Monday morning, as a popped manhole cover prompted a closure at the St. Albert Trail underpass.
An intense thunderstorm late Sunday produced hail and strong wind gusts, while up to 50 millimetres of rain fell in parts of the city, flooding the Yellowhead at 121st and 127th streets and forcing the Edmonton Folk Music Festival to wind down early.
Heavy rains pushed a high volume of air through the drainage system, city officials said, popping the manhole cover off the centre lane at the St. Albert Trail underpass and creating a crater around the manhole.
Traffic was diverted onto the St. Albert Trail turnoffs while city crews worked overnight to reopen the road.
The road was partially reopened around 10 a.m. Monday, with the middle lane remaining closed until further notice, said Brad Vanderhoek, a traffic operations manager with the city.
“We had to get drainage in to check and make sure the system is functioning,” Vanderhoek said.
“From what I can see in pictures, the structure seems fine. It looks like the top asphalt travelling surface is what’s popped off.”
Repairs won’t begin until the road dries out somewhat, likely in the next few days. The road will be reduced to one lane during the repairs for worker safety.
Flooded catch basins also caused problems in the southbound lanes of 97th Street between 127th Avenue and Yellowhead Trail, which led to the closure of the curb lane.
Vanderhoek also noted flooding at the Stadium LRT station led to the temporary closure of the escalator and elevators at the station. The elevator shaft was flooded, a closure that will take some time to rectify, Vanderhoek said.
The city received 60 floodrelated calls — including 35 plugged catch basins — during the storm, mostly sewerrelated trouble calls, said Derek Melmoth, director of drainage operations at the city.
When there’s a lot of rain in a short time, there’s little the city can do to prevent flooding in underpasses, Melmoth said.
“When you get intense durations of rain, they are prone to having more water there,” he said. “When you’re going under underpasses in an intense rain, you should be careful.”
As for the Folk Fest, Ryan Dunch tweeted that usually attendees sing the Ian Tyson’s Four Strong Winds as a finale, but this year “four strong winds ended us. Unplanned, but totally memorable.”