City addresses concerns over burst watermains

“What we find though is, especially the one on 6 Avenue, it wasn’t necessarily due to the frost. That one, I suspect, was [due to] old cast iron pipe and they do unexpectedly break, and that’s what we experienced.”

Koshuta said the city’s 10-year average for watermain breaks is 49, with the 20-year average being roughly 61.

“We are trending to less and less breaks every year,” he said, adding that in 2021, the city experienced 36 watermain bursts. In 2020, that figure was 34.

“In this month of January, we’ve had four already. The 10-year history, or average for January watermain breaks, is five.”

He said although it may seem like the city has experienced more watermain breaks than average this month, that could be because three of the reported breaks came so close together, but “right now we are experiencing average watermain breaks over the 10 years.”

Although he could not say how many kilometres of new piping has been installed in recent times in the city, Koshuta said, “we do have a proactive asset management program that does target old pipe.”

“Primarily, we find our problems with cast iron pipes and that’s found mainly in the downtown core or the older parts of the city.”

He said the city’s annual program target is to replace the cast iron with PVC, the type of piping mostly found on the west side of the city.

“That’s where we have very little problems with watermain breaks. Most of the breaks, as you know, do occur in the older parts of town, primarily in downtown.”

Koshuta said generally, a lot of the cast iron piping in the city was installed “in the 40s, 50s and 60s, and up to the 1970s.”

“In the 70s, that’s when pipes switched over to different materials and then of course, [since the] later 80s, primarily PVC has been used.”

He said the city department is “very confident that once our program continues to target seemingly unpredictable cast iron pipe, we will continue to trend downwards in watermain breaks.”

Koshuta added that crews have noted some “troubled areas” along Stafford Drive, as well as 3 and 4 avenues in the city’s downtown core.

“Those will be areas that we’ll target in the upcoming next two or three years of watermain renewal programs. We do keep a log of all of the breaks and our team will assess which pipes should be replaced.”

WEATHER CHANGES

Koshuta further elaborated on fluctuating weather and how that affects piping. He said, “we have found that the lower the frost is in the ground or at the greater depth, we will run into problems with pipes unexpectedly breaking.”

“Generally, most of our repairs, or watermain breaks for the year, are found through the colder months – October to March.”

He further commented on the benefits of PVC piping.

“PVC, generally it has a 50 to 80-year life, [that’s] what manufacturers have told us and we find we just don’t have to target those replacements right away, so it’s primarily cast iron that we’re looking at replacing in our asset management programs.”

“That annual program has been working quite effectively. We have seen a downward trend in the number of annual watermain breaks that we’ve experienced over the last, I’ll say 35 years since we’ve been tracking [the] data.”

He added that the program costs “generally around 1.8 million to 2 million dollars per year [spent] on replacing the underground infrastructure of the watermains.”

Koshuta concluded that, “the more we replace the old cast iron, troublesome pipes in older areas of town, we will see those numbers, or we should see those numbers [watermain breaks] trend downwards as well but for right now, for 2022, the numbers are consistent with what they have been for the last number of years.”

More on the city’s watermain repair work is available here.

by Justin Goulet

City addresses concerns over burst watermains

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