The City of Calgary is considering micro tunneling to create a twin line along the precast concrete portion of the Bearspaw south water feeder main.

The information was delivered by city administration during a water plan update at the Feb. 12 Infrastructure and Planning Committee meeting. There, they provided an update on plans to solidify Calgary’s water service over the next several years.

While there are few firm details, the twinning plan could include up to five kilometres of redundancy along the Bearspaw segment of the line that has precast concrete and steel wire reinforced pipes. 

Those are the type of six-foot-wide distribution lines that were involved in last summer’s Bearspaw water feeder main break.

Creating the redundancy would allow the City of Calgary to provide service and repairs on the existing line. It will also ensure that there are other water pathways should there be a disruption in either line at some point in the future.

The plan is going through the RFP process and more details on cost, delivery and timelines will be made available to city council later this year. There’s an ambitious tentative timeline to start construction by Q4 this year.

Steve Wyton, manager for asset management planning with the City of Calgary said the microtunneling is the preferred option because it minimizes service disruption to all Calgarians. It also limits the localized impact on businesses and residents in the area.

“Microtunneling is an option that really does fit that bill,” he said.

“It will still require some sort of surface work, where we will have to dig tunnels down to allow the microtunneling work to occur.”

The city had considered slip lining the existing line to add reinforcement, but they said that it would have required multiple service outages over several years, and the pipe would be out of service for a longer duration.

While they still need to iron out specific costs, Wyton said that microtunneling and the slip lining would be comparable in cost. He emphasized that the microtunneling option limits disruptions—and that’s the differentiator.

Cost worries, along with ambitious timelines

Ward 1 Coun. Sonya Sharp, whose area communities were hit hard by last summer’s Bearspaw water feeder main break, said it was important to have a plan in place soon so it can be communicated to the public.

“Not just the residents that live there, but the businesses, they went through a lot last summer,” she said.

“So now that we have some time to work with them and be proactive, maybe it alleviates some stress that they will feel, especially when it comes to the businesses that were hard hit during the last water main.”

Calgary city councillors approved the borrowing of $1 billion for water infrastructure, and Coun. Sharp said she believe that part of that will help fund the Bearspaw upgrades.

While cost is always front of mind, Coun. Sharp said that part of the problem is big expenses like these have been repeatedly deferred, leading Calgary to situations like the water main failure.

“Now we know as a council and future councils need to be paying attention to what infrastructure means to our city,” she said.

Ward 7 Coun. Terry Wong hopes there’s lessons learned from last time, and that businesses and residents have enough time to process that additional water main work is going to happen – sooner rather than later.

Still, Coun. Wong said that given the current constraints on city staff, a Q4 construction start is fairly ambitious.

“When you recognize the different projects that have got going, even if you run a concurrent program, project managing, that is a significant task,” he said.

“So, if they can get it done, great. Does it push into 2027? It’s possible.”

Wyton said that Q4 is an aggressive timeline.

“What’s very critical for us, though, is to get out and make sure that we are talking with citizens that are directly affected by this work,” he said.

“So, that will be coming back as part of our implementation plan, a more fulsome communications plan.”

Along with the Bearspaw south upgrade, councillors also heard about the north Calgary water servicing project. It would provide partial redundancy for the Bearspaw south feeder main and six other feeder mains. 

It also included a cross-tie feeder main, to provide redundancy and improve system pressure for Saddle Ridge, Taradale, Martindale and Falconridge.