Toronto’s water mains having worst winter in 20 years
Watch the video above: Toronto’s water mains having the worst winter in 20 years. Mark McAllister reports.
City crews are working overtime to keep up with Toronto’s chilly winter, which has led to the most water main breaks in 20 years.
Not only does the prolonged cold weather mean more breaks; it also means each break takes more time and money to fix.
From Jan. 1 to March 6 there were 874 water main breaks, according to the City of Toronto’s preliminary data. The last time the numbers were that high was in 1994, where there were 1147 breaks over the same time period. There were 484 breaks by March 6 of last year, according to data released on the City of Toronto’s Open Data site.
Chart: Toronto water main breaks per year Jan. 1 – March 6
In the past week, crews have had to deal with an average of 20 to 25 breaks every day, said Mario Crognale, director of district operations for Toronto Water. “The difference this year that we’ve seen is, not only has it been cold, but it’s been cold for a long period of time.
“So when you have an extended period of cold, sub-zero, the frost penetrates deeper, and when frost gets into the ground, it puts pressure on a weak pipe.”
As soil freezes, it expands, squeezing the pipes. And if they’re already weakened, they can crack.
Frost this year has penetrated about 1.5 metres into the ground, said Crognale, which is highly unusual. This means it has reached the pipes, which are also mostly buried about five feet deep, according to the city’s website. Most years, Crognale said, the frost only penetrates about a metre deep.
Strong pipes can withstand the pressure, but not all of Toronto is that lucky. North York and Etobicoke historically have far more water main breaks than Scarborough or even the downtown core: Their pipes are thinner, the soil more corrosive.
Map: Watermain breaks in Toronto, 1990-2013
Click here to view map in own window.
“It’s always been like that,” Crognale said. “The type of soil that you have in Etobicoke and North York is conducive to accelerating corrosion in the metal pipes.”
Downtown, with its Victorian-era pipes, is luckier. “Believe it or not, the older the pipes, the thicker the metal is. When you have a thicker-walled pipe, as it was and as it is in the old City of Toronto, then it takes longer for that pipe to corrode and result in a watermain failure.” Downtown’s sandy soil is also less corrosive than the clay found in Etobicoke and North York.
Toronto Water has been trying to combat the problem pipes, starting with the very worst. When a regular, 150-millimetre water main exceeds a ten-year average of two breaks per kilometre per year, it gets nominated for replacement. Crews proactively replace between 40 and 60 kilometres of pipes a year, Crognale said.
The city also lines roughly 30 to 50 kilometres of pipes a year with resin-impregnated fibreglass to prevent further leaks.
Then there’s “cathodic protection”: Rather than replacing an iron pipe that could corrode in future, the city attaches a piece of zinc or magnesium at several points along the length of the water main. The zinc or magnesium anode then corrodes instead of the pipe.
“It buys us time. It actually prolongs the lifetime of our pipe,” Crognale said. Adding anodes can mean a pipe that was expected to fail in three years can actually last for 15 or more, he said. The city protects roughly 100 kilometres of pipe every year in this way.
But 300 kilometres a year is peanuts in a city with about 6,000 kilometres of pipe. So there are plenty of breaks, and fixing them can be costly.
The average break on a side street costs about $8,000, said Crognale. But the cost can increase dramatically as a break damages the roadway or surrounding property. He estimates that a major water main break on Bayview Avenue south of Finch Avenue E. on Feb. 9 could cost the city more than $60,000, once repairing the road, traffic management, repaving and other costs are factored in. This kind of break is unusually bad, but costs do vary widely depending on exactly where the break is and what kind of damage the water causes.
And costs are up this year, he says. “The average break, it’s costing us a little more. It’s taking us a little longer to complete the repairs because the frost is deeper. It’s probably taking us, on the average, I’d say about 25 per cent longer to do the repair itself.”
In the past few years, he said, his department spent about $10 million a year repairing broken water mains and, according to the city’s website, roughly $90 million a year on preventative water main replacement and rehabilitation.
“My expectation is, if you compare things over the year, we’re probably going to be over budget by some amount, but right now, I can’t estimate what that’s going to be.” Toronto Water has a total capital budget of $613.3 million for 2014, and an operating budget of $403.2 million, according to budget documents. That includes funds to repair problems, operate water and sewage treatment plants and upgrade infrastructure.
Crognale assures worried customers – or those without running water thanks to a break – that city crews are out working to fix the breaks, though it might be taking a little longer because of the volume of work.
“We’re trying, we’re working 24/7, so be patient with us. If there is a water interruption that a system failure has caused, we’re trying to restore that service as soon as possible with all the means that we have.”
Note: Story contains information licensed under the Open Government Licence – Toronto
Editor’s note: The original version of this story contained incorrect information about Toronto Water’s capital and operating budgets. We regret the error.