Potholes

Did you find a pothole on a city street? Fill out an incident report here to notify staff. 

Please be advised that the City of Niagara Falls may not be responsible if you damage your vehicle after driving over a pothole in the roadway.

The provincial government has established standards for maintenance of municipal roadways. When the City of Niagara Falls has maintained the roadways in accordance to this provincial standard then the City is not responsible for damages to a vehicle caused by driving over a pothole.

Any claims for losses are to be directed to our Risk Management department.

ABC’s of Potholes

There are only three things that can kill a road – water, water, and water. For the majority of municipal roads, potholes start to form when water seeps into the gravel subbase and undermines the pavement. The weight of vehicles going over the unsupported pavement flexes the asphalt, which weakens, cracks, and then falls away leaving a pothole. The more traffic there is, the more damage there will be. Heavily travelled roads or roads with a lot of truck traffic are more prone to potholes.

For major arterial roads with two or more layers of asphalt (thicker than 150 mm), the mechanism is slightly different. With spring conditions, the top layer de-bonds and breaks up under the repeated loading of the traffic leaving a pothole and exposing the lower layer of pavement. With the surface lift gone, the water ponds in the hole, leading to further infiltration of water into the pavement and ultimately into the subbase. 

Potholes are prevalent in the spring because the winter freeze thaw cycles which open up the cracks in the asphalt, allowing more water to penetrate. When the water in the subbase freezes, it expands and increases in volume by 9%, pushing up the pavement and further weakening it. Spring temperatures warm the cold pavement, melting the ice, creating air pockets that leave the pavement unsupported. A winter of heavy snow or rain and repeated freeze-thaw cycles means a big pothole season ahead.

More information can be found in the Ontario Hot Mix Producers Association (OHMPA) brochure.