Southern Ontario's temperature rollercoaster hasn't been as extreme as Alberta's, but the first few months of 2011 have seen their share of extreme cold followed by a sudden return to seasonal temperatures.
According to Mario Crognale, director of district operations with Toronto Water, the fluctuating temperatures are taking their toll on the aging water infrastructure in the City of Toronto.
Division staff have dealt with 375 watermain breaks since January 1st - almost 100 more than the same period of time last year.
The reason, Crognale says, is the pipes - some of which are more than 80 years old - can't withstand the pressure placed on them when the surrounding soil freezes.
“Corrosion occurs ... resulting in the pipe becoming thinner and more brittle,” he explains. “The pressure within the pipe itself compounded with the external pressure (of the freezing soil) will result in the actual failure of the pipe.”
The frequent ruptures are a costly problem, Crognale says.
The average watermain break costs the city about $7,000. With 1,400 to 1,500 breaks a year, that's $10 million just in repair costs.
Toronto Water has been working to replace the old cast iron watermains installed in the 1950s and 60s and reinforce newer mains whenever possible, but pipes are failing faster than crews can get to them.
“Water main breaks have been with us for many years, and they will be with us for many years to come,” Crognale says. “It's going to be many years before the water distribution system is replaced entirely.”