Calgary sinkhole count rises to 200 after floods

Calgary is dealing with a growing number of sinkholes since the floods, with road crews repairing roughly 200 this summer.

• Flood-damaged Calgary roads cost city $25M

City spokesman Sean Somers said in a typical year crews might see a dozen sinkholes, usually caused by water main breaks.

But June flooding has meant a huge increase in sinkholes, even on residential properties around the city.

Sinkholes are formed through water movement underground.

"The gravel below the pavement essentially gets washed away, so once that gravel is washed away there is nothing to support the vehicle or vehicles and so it collapses."

Somers says his guess is the worst is over now, but he adds there is no way of predicting when or where a sinkhole will occur.