The next phase of construction on the Bearspaw South feeder main replacement line will begin this month, as the city continues an accelerated project to replace the critical water transmission line that has burst twice in the past two years.
City officials announced Monday that work on Stage B of the new parallel pipeline will start at two locations: 83rd Street between 33rd and 34th Avenue N.W., and 77th Street between 33rd and 34th Avenue N.W.
Starting next month, the new line will begin installation below 34th Avenue N.W. between 73rd Street and 89th Street, in the community of Bowness. Stage B is expected to be complete by the end of October, according to the city.
“Once cross-connection work is complete, we will begin construction for the feeder main on 34th Avenue N.W. in June 2026, starting at locations between 79th and 80th Street N.W., and between 85th and 86th Street N.W.,” the city said in a news release.
“Residents in the area should expect traffic impacts, detours, noise, dust, temporary parking restrictions and short-term access changes during construction. Drivers are encouraged to follow posted detours and use extra care when travelling through residential streets.”
The new steel line will replace a 50-year-old feeder main that burst unexpectedly below 16th Avenue N.W. on June 5, 2024, and then again on Dec. 30, 2025. The Bearspaw South main transports approximately 60 per cent of Calgary’s treated water and is the most important artery of the city’s water system. Both times the pipe broke plunged Calgary into weeks-long bouts of water restrictions.
Since the second rupture late last year, Mayor Jeromy Farkas has repeatedly described the Bearspaw line as “terminally ill” and a “ticking time bomb” that could rupture again at any moment, despite recent reinforcements. He has called the accelerated project to replace it Calgary’s “moon shot.”
The City of Calgary will begin Stage B construction on the Bearspaw South feeder main replacement project in May 2026, installing a new parallel steel feeder main along 34th Avenue N.W., between 73rd Street N.W. and 89th Street N.W. Photo taken in Calgary on Monday, May 11, 2026.
Work began in January and the new line is expected to be in operation by the end of 2026. Earlier this spring, city council unanimously supported a $609-million capital budget adjustment to help pay for some of the city’s water infrastructure upgrades, including the feeder main replacement.
Differing from Stage A, which used a microtunneling technique, the next phase of pipe installation will use an open-cut construction method. Crews will excavate 34th Avenue within the public right-of-way to install the new pipe. This method, also referred to as “cut-and-cover,” involves digging a trench to restore the surface to its pre-construction state, installing the new line, and then backfilling the earth.
An open-cut approach was selected for several operational reasons, argued general manager of infrastructure services Michael Thompson — mainly that it is the fastest way to replace the existing feeder main, which is one block away under 33rd Avenue.
“Just from a timing perspective, we are very focused on getting this replacement pipe completed by December of this year, so that we don’t have to deal with the risk as a community of having the Bearspaw feeder main fail in the winter, like we experienced on Dec. 30,” he said.
New water restrictions anticipated for October
The pipe is being installed at varying levels of depth underground, ranging from 10 to 25 metres below the surface.
Crews are installing concrete pipe as a slip line for the steel pipe, which Thompson said is going to be inserted after the concrete is installed.
He said crews reached a milestone last week, with one kilometre of concrete pipe now installed, out of nearly 3.7 kilometres. Stage A construction is slated to last until the end of August.
Thompson hinted that Calgarians will have to once again endure Stage 4 water restrictions in the fall, in order for the city to shut down the existing feeder main and connect it to the new main.
Those restrictions are expected to last three weeks and take place in October, he said, adding more details will be known by the summer.
The City of Calgary will begin Stage B construction on the Bearspaw South feeder main replacement project in May 2026, installing a new parallel steel feeder main along 34th Avenue N.W., between 73rd Street N.W. and 89th Street N.W. Photo taken in Calgary on Monday, May 11, 2026.
For households on 34th Avenue, rolling detours will be implemented as construction progresses and the roadway is torn up, depending on which block crews are working on.
On each impacted block, residents will access their homes either through the alleys or from the sides, said Darren Finney, the city’s manager of major projects. He said construction on each block will last about two months, on average.
“We’re working with all the residents and business relations group,” he said Monday. “So yes, there will be some people who can’t access the front of their home. And as that moves along, the details will be rolling, and that will change as it progresses.”
Stage A construction update
Stage A construction, which will see the pipe laid from the Shaganappi Pump Station to 73rd Street N.W. on the west side of the Bow River, remains on track, Thompson said.
Microtunneling between the shaft located at Sarcee Trail and the Bow River shaft, located west of Bow River near Mainstreet Condominiums, began April 27.
Construction of a sixth and final tunnelling shaft on 16th Avenue N.W. near 44th Street is scheduled to begin this Wednesday, according to Thompson.
“We always knew we would need that, but we waited until, from a schedule perspective, right before we needed it to build it so that we reduced impacts to traffic on 16th Avenue,” he said. “And so as the work progresses, we now need that vertical shaft.”
Due to ongoing construction, parking availability at Edworthy Park is significantly reduced. Visitors are encouraged to plan ahead and anticipate limited on‑site parking, particularly during peak periods.
The City of Calgary will begin Stage B construction on the Bearspaw South feeder main replacement project in May 2026, installing a new parallel steel feeder main along 34th Avenue N.W., between 73rd Street N.W. and 89th Street N.W. Photo taken in Calgary on Monday, May 11, 2026.