Coulda, woulda, shoulda seen it coming. But didn’t. Or wished it would just go away.That’s because the city of Calgary failed to heed decades of warnings in other cities — including Edmonton — over the failure of the kind of prestressed concrete cylinder pipe (PCCP) used in the Bearspaw feeder main.On Wednesday, the city announced it will be taking the entire system down on August 26 for most of the month of September to initiate what it described as “urgent” repairs to the mainline that serves most of northern Calgary and outlying communities like Airdrie..That means residents will go back into Stage 4 water restrictions that ban outdoor watering and mandate non-essential indoor use — three minute showers — that they went through for most of the month of June."This news is not what any of us wanted to hear," says Mayor Jyoti Gondek. "To everyone in the Calgary region, particularly residents and businesses in Bowness and Montgomery, I understand how much this impacts your lives. You have my word that we will continue to do everything we can to improve the stability and security of water in our city."Though it isn’t a repeat of the same emergency situation that occurred in June, it shouldn’t have been unexpected, either. In fact, it should have been anticipated based on the experience of other cities across North America and indeed, the world..Failures on PCCP water pipes have been well documented since at least the 1990s when a major water failure prompted the city of Denver — which serves as a good analogue to Calgary — to replace 15 miles of its water system at the then-staggering cost of about USD$2 million.In fact, it continues to monitor and replace other existing sections of similar pipe to this day, after installing an acoustic monitoring system like the one touted by Mayor Jyoti Gondek in 2014.Since then, the system has detected 543 wire breaks according to the Denver Water website.Even in Edmonton, EPCOR in November of 2019 averted a major water disaster by deploying an in-line ‘smart ball’ acoustic monitoring system combined with an electromagnetic detection platform to identify weak areas..Not only did it prevent what could have been a major catastrophe in the middle of winter, it also saved taxpayers what turned out to be tens of millions of dollars, given Calgary’s initial estimate of about CAD$20 million to fix the additional mainline break.“By assessing the Northside Pipeline, we avoided a catastrophic failure that could have disrupted water service to tens of thousands of people in Alberta’s Northeast Capital Region. Also, we gained valuable knowledge on the condition of the pipeline and how best to execute our work in the future to maintain system integrity,” said Andrew Rees, who was EPCOR’s water distribution manager at the time..Even with those prior case studies, Gondek said she was “grateful that we have the PipeDiver results. That important information is allowing us to immediately act to protect our water system against potential breaks.”And even now, where other cities like Denver replaced the questionable sections with steel pipe with a life expectancy of 100 years, Calgary is opting for the so-called ‘reinforced concrete method’ which involves exposing the pipe through excavation, constructing an exterior reinforcing steel cage, pouring concrete and backfilling the excavation. In a news release, the city said it is a “preferred method” because it doesn’t involve removing individual pipe sections, which means it’s presumably cheaper.“These urgent repairs are required to proactively support the stability of our water system. We are committed to getting the required repairs completed to keep water flowing safely to you,” added infrastructure service manager Michael Thompson.
