Recent fluctuations in temperature combined with heavy rain could increase the number of potholes in Waterloo Region, according to a Kitchener engineering consultant. 

"This year, most cities are reporting an average year for potholes," said Barbara Robinson, president of Norton Engineering. "Although, right now we're seeing freeze-thaw cycles. So, it might get worse over the next few weeks."

Robinson said potholes form when water under the asphalt freezes and expands, causing the road to bubble. When the frozen water thaws, it contracts, leaving a gap under the asphalt.

Problematic pothole repairs

"When cars and trucks drive over that pavement that has a hole or gap, it starts to collapse a little bit," she said. "So, that's the beginning of a pothole."

There are regulations in Ontario that require municipalities to repair potholes within a 30 day period, but Robinson said repairing a pothole doesn't always solve the problem.

"It's all about the bond between the existing asphalt and the new asphalt that we throw in the hole," she said. "If that bond isn't perfect, it doesn't stick properly, and the repair will either pop out or there's another opportunity for water to get in around the crack where we repaired the pothole."

As a result, potholes may have to be repaired multiple times during the year, but Robinson says the repairs are fairly cheap, costing only $25 a hole.