Could Edmonton’s water system see the same issues as Calgary’s?

Edmonton's downtown Epcor Tower and city hall in an undated photo. (CTV News Edmonton)

Calgary’s water infrastructure has made national headlines in the last couple of weeks, leading some Edmontonians to beg the question – could that happen here?

Epcor’s communications director, Martin Kennedy, says while the risk is never zero, Edmonton’s water system fares considerably better than the national average.

“We’ve had a lot of interest from customers and others in the light of what happened in Calgary, asking, ‘How does Epcor manage Edmonton water infrastructure?’” he told CTV News Edmonton on Tuesday.

“Every city’s water system is different. They have different geographies, different ages and how the cities grew varied over time.”

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Epcor, Edmonton’s sole water, wastewater and storm drainage provider, works with almost 4,400 km of water pipe in Edmonton.

Granted, if you were to add up every water line in the city – sanitary and stormwater lines included – you’d have enough pipe and tunnel to go from Edmonton to Argentina, Kennedy added.

The water system in Edmonton consists of water transmission mains, which are larger in diameter – between 350 mm and 1,500 mm – and distribution mains, which are less than 350 mm in diameter.

The water pipes are made up of varying types of concrete, cast iron and polyvinyl chloride, also known as PVC.

The Bearspaw South feeder main, which broke in Calgary, was made of prestressed concrete cylinder pipe – a material Epcor says it hasn’t installed in its Edmonton system in about 35 years and is currently found in less than three per cent of the city’s large pipes.

“Breaks or leaks in the largest lines in Edmonton’s network have been rare and have been managed without significant impact on customers to date,” the statement noted.

Edmonton water infrastructure investment

Edmonton is no stranger to water main breaks, but Kennedy said the scale of those breaks is often mitigated by ongoing infrastructure renewal and crew response times.

“In Edmonton, there’s been steady, long-term investment in utility liability and replacement, and that’s led to some really strong performance,” he noted.

Around 80 per cent of Epcor’s capital gets invested into the city’s water system each year, he explained, which goes toward replacing parts of the system that are nearing their end of life.

On average, municipalities across Canada lose about 17 per cent of treated water through leaks in their system. That number in Edmonton is closer to five per cent.

Epcor also uses a third-party regulator, separate from council’s municipal operations, to evaluate long-term annual plans for their operations.

“We translate those plans into the revenue required to run the system and the rates that we would need to charge customers, and then we deliver that,” he said.

Another near 20 per cent of Epcor capital, Kennedy said, goes toward improving environmental outcomes – something the utility giant is stressing as the city expands both in boundary and in population density.

Why do water mains break?

In the 1980s, Edmonton would see about 1,600 water main breaks annually. Today, that number is between 300 and 400.

“We can’t prevent every break in the system … but what we can do is be sure that we are ready to mobilize when those happen,” Kennedy said.

A large portion of water main breaks, he said, happen because of rapid freezing or thawing, which causes the ground to shift. If the ground shifts too much, a pipe can break.

Last week, for example, a water main break in south Edmonton shut down part of 99 Street until Saturday morning because of the thaw the city experienced.

“Utility systems are large and complex … so our minds and our thoughts are on being cautious and prudent and planning well,” Kennedy said.