City of Calgary determines cause of Cranston sinkhole

Officials with the City of Calgary believe they've uncovered the cause of an enormous sinkhole that tore through a road in the community of Cranston.

The cavernous crater formed on Tuesday in the area of Cranston Boulevard and Cranston Drive S.E. shortly before 6 p.m.

City officials taped off the area and returned on Wednesday with heavy machinery to start ripping up the road.

Maryann Santiago, whose home is directly in front of the sinkhole, says it grew greatly between Tuesday night and Wednesday morning.

"It was probably one fourth as big (as now)," she said. "Overnight it just got bigger and bigger."

Staff with the city's water services department dug five metres down to determine why the road collapsed.

After several hours, city officials concluded the cause was a leak in a water line into a nearby park, which feeds a pond and waterfall.

"We believe it got turned on about noon (Tuesday)," said city spokesperson Lee Dupras. "It was running for about six, seven hours before the sinkhole started."

A sinkhole formed in the area of Cranston Boulevard and Cranston Drive S.E. on Tuesday, May 23, 2023. Dupras says sinkholes can develop quickly, especially when there is a large amount of water.

"Running water does tend to take (fine particles) away underground quite quickly. The asphalt, because of the thickness, does tend to hold up for a much longer period of time."  

Dupras says no one in the area should expect to be without water as the repairs proceed.

He expects the work to be done in a week or less. 

"We're going to peel back the asphalt and try to determine where there's any voids," he said. "Then we can rehabilitate it and get it paved."