There’s a reason you might see square-shaped repairs on Edmonton’s roads.

Three years ago, the city began a pilot project on a new way to repair potholes in the city called putty repair patches.

“They look square, almost like a goop-type material, but they are actually intended to fill holes or cracks in the pavement to keep water from getting in,” said Caitlin Zerebeski, acting director of the city ​​parks and highways departments.

Zerebeski says they aim to create a barrier on the road surface.

“This also creates a smooth surface on top, which prevents any further water penetration or further pothole formation,” she said.

The thick liquid is put into a form that is poured into potholes in the road.

“That’s where you see those perfect squares, those perfect lines on the side, because you’re forming the material into the repair area that you’re looking for.”

Thick liquid used in a putty repair in Edmonton. (CTV Edmonton/Amanda Anderson)

The city repairs potholes all year round with 10 dedicated teams in the summer,

Potholes form when water enters a roadway. When it freezes and thaws, it creates small voids beneath the road surface that turn into potholes. Zerebeski says Edmonton is one of the few cities in northern Canada that uses asphalt year-round.

The city says it is using putty repair patches more often because it sees fewer potholes in the city. In 2021, the city recorded more than 17,000 pothole notifications. In 2023, there would be just over 6,500.

When the pilot project began three years ago, the method was used on high-speed roads like the Yellowhead Highway and Whitemud Drive. The type of asphalt used on these roads is best for mastic repairs because it is not susceptible to rutting or defects from heavy traffic.

The city says it prioritizes repairing potholes based on their size, location and severity. If you see a pothole that needs attention, you can report it to 311.

With files from Amanda Anderson of CTV Edmonton