Ontario Construction News staff writer
The City of Calgary’s Bearspaw South Feeder Main Replacement Project is continuing to advance on schedule, with microtunnelling and installation of the concrete carrier pipe for the first stage now complete.
The milestone marks a significant step in the project to replace a critical section of Calgary’s drinking water infrastructure.
Ward & Burke Microtunneling Ltd. is carrying out the microtunnelling work, while Graham Construction & Engineering Inc. is serving as construction manager for the project.
Construction on Stage A began in January and involved approximately 3.7 kilometres of microtunnelling between the Shaganappi Pump Station and 73 Street N.W. The method allows crews to install the new feeder main beneath existing infrastructure while minimizing surface disruption.
The work involved first installing a concrete carrier pipe underground, followed by installation of the new steel feeder main inside it.
More than two kilometres of steel pipe have now been installed inside the carrier pipe, with the work remaining on schedule.
“The completion of Stage A microtunneling is a significant step forward for the project,” said Darren Finney, manager of major projects.
“This complex work involved tunneling beneath major infrastructure, minimizing impacts on the community. With the concrete carrier pipe now in place, we will continue installing the new steel feeder main, preparing for the critical system connection work planned for the fall.”
Meanwhile, open-cut construction on Stage B began in June along 34 Avenue N.W. in Bowness.
More than one kilometre of new steel feeder main has been installed, bringing Stage B to approximately 40 per cent complete. Construction is currently underway on three blocks, while four blocks where installation has been completed have reopened to traffic. Two additional blocks are expected to reopen next week.
Construction is being completed in sections, with roadways, sidewalks and property access restored as work advances.
The next major phase is expected to begin in September, when crews will start connecting the new feeder main to Calgary’s existing drinking water system.
Work at the Shaganappi Pump Station is expected to begin in September. At the same time, unrelated work associated with the North Calgary Water Servicing feeder main will require a temporary shutdown of the Bearspaw Water Treatment Plant in mid-September.
City officials say temporary outdoor water restrictions may be required, depending on weather conditions and water demand. A final decision will be made closer to the start of the work.
Pipe tie-in connections are expected to begin in mid-October at various locations along the new feeder main. The work will involve open-cut construction similar to the ongoing Stage B work.
The connections will require Stage 4 outdoor water restrictions and indoor water conservation while the work is underway.
Commissioning of the new feeder main is expected to begin in mid-November. The process will include disinfecting the pipe, filling it with water and taking the existing feeder main out of service. No restrictions are currently anticipated during commissioning.
While the feeder main is shut down for the connection work, the city will also complete six additional repairs on a separate 1,500-millimetre section of the Bearspaw South Feeder Main between the Shaganappi Pump Station and the Memorial Pump Station along Parkdale Boulevard and Memorial Drive N.W.
Recent condition assessments identified six locations requiring proactive repairs. The city said the 1,500-mm section remains in good overall condition and does not require replacement.
Instead, crews will carry out targeted repairs by excavating at six locations, removing sections of pipe and replacing them with new steel segments. The work will involve around-the-clock construction.
The city said completing the repairs while the feeder main is already out of service for planned connection work is expected to reduce future risk and disruption.
Estimated construction dates remain subject to change based on project timelines and logistics.
