Delayed inspections, risk of more ruptures: 5 takeaways from report on Calgary's water main catastrophe

An independent panel report released its report on the 2024 break of the Bearspaw South feeder main Wednesday, amid the backdrop of a second catastrophic break of the same main last week.

While this latest break was not part of their review, the panel’s findings point to decades of passed-up opportunities to inspect the feeder main, despite the fact it was identified as being at risk of failure.

Here are some of the key takeaways. 

The report says the Bearspaw South feeder main was identified as vulnerable after the 2004 rupture of the McKnight feeder main in northeast Calgary, which used the same type of material: prestressed concrete cylinder pipe. (PCCP).

That break flooded McKnight Boulevard and temporarily left about 100,000 northeast residents without water.

The Bearspaw pipe’s age — it was installed in the mid 1970s — and design were also considered risk factors.

But those vulnerabilities were never addressed, the panel found, and three recommendations over five years to inspect the pipe (in 2017, 2020 and 2022,) were either deferred or redirected as the city focused on other priorities.

The report says infrastructure is lagging in many Canadian cities, with more than one-quarter of water mains across the country in need of repair.

But it says the risk is elevated in Calgary, due to a boom in population growth and higher maintenance costs associated with the city's low population density, where the system supports a sprawling city.

“The city was growing at a remarkable pace, and quite often, growth investments overtook some of the resilience and redundancy investments that should have been undertaken at the time,” panel chair Siegfried Kiefer told a news conference this week. 

The panel said the City of Calgary’s “risk tolerance has been too high for critical infrastructure."

“This is a staggering failure. It is the equivalent of a plane crash caused by a faulty part, and then refusing to replace the same part on identical aircraft,” Ward 12 Coun. Mike Jamieson said in a statement. 

But Kerry Black, associate civil engineering professor at the University of Calgary, said it is important not to point fingers.

“[These are] collective decisions where we are trying to prioritize what’s most important to the city," she said. “You can’t fix everything, so you prioritize the things that are the highest risk."