Cold weather brings more water main breaks, city says

WATCH ABOVE: Marianne Dimain explains why cold weather can lead to more water main breaks. 

TORONTO – As the cold weather blows in, Toronto officials expect to see a lot of broken water mains.

On average city crews repair 1,100 broken water mains every year. In 2013, that number was even higher after one of the coldest winters Toronto has seen in more than two decades. Between last January and May, crews repaired more than 1,400 breaks.

“In the winter the colder weather what can happen is if the frost in the ground gets deep enough it applies pressure to the existing pipes,” said Derek Thomas, Acting Director of Toronto Water.

“With the aging infrastructure those pipes can rupture.”

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Water mains break due to corrosion, leaks that can lead to a pipe collapse, or cold temperatures that make the soil freeze and expand creating pressure that can make the pipe burst. When the pipe does burst, it costs the city approximately $8,000 to repair. That money comes from the annual budget of $110 million to improve the water main system. The water tax also helps cover the cost.

“The challenge that we have is water consumption is going down and so we’re getting less revenue in,” said Toronto City Councillor Denzil Minnan-Wong. “But we still have the same number of pipes that we have to fix every year and they still continue to get old so it’s a challenge for the city.”

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The city replaces 40 to 60 kilometres of water mains every year. Pipes are chosen based on several factors like the material of the pipe, how many breaks its had and its age. Seventeen per cent of the city’s water mains are 80 to 100 years old and 6.5 per cent are more than a century old.  Most are made with cast or ductile iron but smaller cast iron water mains constructed in the 1950’s and 1960’s are more likely to break because they have thinner walls.

If the break isn’t too serious, crews repair the break with a clamp or replace the broken section.

“We’ve got hundreds of miles of pipe,” said Minnan-Wong. “We do replacement and we do realignings. We get to them as fast as we can.”

According to the city of Toronto, water mains in North York, Scarborough and Etobicoke have the highest rate of breaks because the mains are found in clay soil which makes it easier to break.