Here’s what we know about the 5 new hotspots on the broken water main: City of Calgary

City officials answered questions Friday and Saturday after it was revealed that 5 new hotspots need to be repaired on a broken water main that's impacting city water supply. (Photo: X@CityofCalgary)

Late Friday afternoon, the City of Calgary held a media availability to deliver an update on the status of the 16 Avenue water main break that delivered shocking news.

It was revealed  that a robot sent into the broken pipe had identified five additional hotspots that needed immediate attention, pushing back the timeline for completion of the repairs by an estimated three to five weeks.

Francois Bouchart, the city’s capital priorities and investments director, gave an update Friday which included the news that 300 metres of the pipe remain to be inspected -- with the possibility that more hotspots could be discovered.

“There could be other locations (along the pipe) that need to be addressed,” he said.

While Bouchart conceded the possibility that there could be more hotspots that require fixing, he said that wouldn’t extend the timeline for repairs.

“It would not add to the timeline in terms of putting the section of pipe that we’ve drained back into service,” he said. "The only section that we’re looking at right now in terms of inspections is the remaining 300 meters that had water in it, and unfortunately the robot can’t operate when there is water in the pipe.

“We’ll know in the next day or so because we’re collecting the data right now.

“Once we have the data, we need to analyze and identify whether or not there’s additional locations (hotspots)," he said, "but our strategy is to do concurrent repairs as much as possible. And therefore if we did identify additional locations, then it would become part of that package that we’re trying to deliver.”

Saturday afternoon, Bouchart said the final 300 metres were drained overnight but the robot still hadn't been sent in to the pipe to assess it.

"We should have the analysis completed by Monday," he said.

The city declared a state of local emergency Saturday morning.

More inventory needed

Bouchart also said the city doesn’t have all the pipe on hand that it needs to do the fixes.

“It’s very early for us to say when we’ll be able to get those pipe sizes into Calgary,” he said. “These are not off the shelf, we always have some pipes sitting on the shelf – we had our critical parts inventory with some of it and what we’re finding is that we need more than what our inventory allows, so we’re reaching out to other utilities around North America.

“There are some other solutions, because the pipe hasn’t actually failed,” he added “There might be an issue with it, but it still hasn’t collapsed and therefore we can use other technologies, like strapping the pipe down, and using other technologies to provide that structural integrity that’s needed before the pressure can be – the pipe can be re-pressurized.”

Bouchart said getting pipe delivered from other jurisdictions won’t add to the timeline, either.

“We factored in our ability to bring pipe materials and other materials we need within the estimate we have of three to five weeks. That’s been factored in.”

Transcript

Here’s a transcript highlighting Bouchart’s explanation of what’s wrong and what’s being done to fix it.

It’s been slightly edited for clarity.

“A significant contributing factor was the breakage of pre-stressed steel wires,” he said. “When these wires break in multiple places, it weakens the pipe and can lead to a catastrophic failure, as we are experiencing.

“As shown, the wires are coiled within an inner layer of concrete pipe.

“The feeder main is constructed with pipe segments that are 16 feet and the steel wire wraps approximately 350 times, like a Slinky, around each pipe segment.

“This wire provides important structural stability for the pipe, to help manage high water pressures,” he said.

“As the pipe ages, it’s normal for some of the wires to break without compromising the integrity of the pipe. However it becomes problematic as the number of breaks increases.

“So far,” he said, continuing, “we have inspected 4.3 kilometres of pipe to see if there are any other issues. We have now received the data that has helped us to get a clear picture of what we’re dealing with.

“We have discovered five hot spots where significant breakage has occurred and require critical and urgent repair.

“The location of these five hot spots are southeast of the current break before the Shaganappi pump station.

“This station is located in north Edworthy Park at the bottom of Shaganappi Trail.”

'Catastrophic pipe failure'

“As we saw in our current break,” Bouchart said, “when the wires break in multiple places, it weakens the pipe and can lead to a catastrophic pipe failure.

“The degree of breakage we are seeing in these sections of pipe require emergency repair.

“Our decision is that we repair these locations as quickly and safely and as effectively as we can.

“Our team of internal and external engineers have been working hard to determine solutions to this problem.

“The repairs will consist of a variety of technologies, including full pipe segment replacement and external reinforcements of pipe segments.

“Our assessment shows the hotspots cannot safely withstand the amount of pressure we need to run through the feeder main.

“This means if we weren’t to complete the repairs needed to the feeder main now, it would be at high risk of additional catastrophic breaks.

“The risk is simply too high,” he added. “We need to act immediately to ensure long-term sustainability.”

Next steps

“Our next step is that we have an additional 300 meters of pipe that still had water and didn’t allow us to complete the inspection.

“We are draining it now and checking to see if there are any additional hotspots that will also be needed to be fixed immediately," he said.

“We are working with partners across North America to source parts we need for an immediate repair.

“We are committed to getting this done as fast as possible while working safely and protecting public health.

“We will be working around the clock to get this done and restore normal water service but it will take time.

“Our initial estimates are that the work will take three to five weeks to complete. We are actively looking at ways to speed the work up but not at the risk of public health or the quality of work.

“What this means is we can’t run water through the south Bearspaw feeder main while the hotspots are being repaired.

“This means that we’ll continue to rely on water from the Glenmore Water Treatment Plant to supply Calgary and surrounding communities until the repairs are complete.

“We need to ask everyone to continue to refrain from using water for outdoor uses and to conserve on indoor use until the repairs are complete.

“The expertise of our internal and external engineers, along with our colleagues in water services operating the system have delivered an excellent analysis.

“This is the best solution to ensure the sustainability and safety of our city’s water supply.”