Preliminary findings from Bearspaw South Feeder Main pipe investigation to be shared with Calgarians November 26

City Administration will be providing a public update on the preliminary findings from the Pipe Investigation at the regular Council Meeting on November 26. The purpose of the Pipe Investigation, overseen by Associated Engineering and Pure Technologies is to understand the factors that led to the deterioration of the feeder main and its failure on June 5, 2024.

The preliminary findings indicate that several different factors may have contributed to the feeder main failure, including:

• microcracking of the protective mortar outer layer of the pipe;
• high chloride levels in soil at various locations;
• wires which snapped due to corrosion and hydrogen embrittlement.

From these findings, the report indicated that there was not one specific factor that led to the failure of the feeder main in June.

“The Bearspaw South Feeder Main is a critical piece of infrastructure, and it is responding well to the rehabilitation work that was completed between June and November, and is now stabilized,” says Michael Thompson, General Manager of Infrastructure Services. “Through our acoustic monitoring, we have recorded only two wire snaps on the feeder main between October and November. Throughout July and August, there were 23 wire snaps.”

The preliminary review of the design and operations also confirmed the original design of the pipe was consistent with the proper guidelines of the time and operations of the pipeline were well within the design parameters of the pipe.

Key Updates and Future Plans

The final Pipe Investigation report will be presented at the Infrastructure and Planning Committee on December 11. The City is currently reviewing options for long term rehabilitation of the feeder main and continues with contingency planning by developing an enhanced emergency response plan, equipping the feeder main with Acoustic Fibre Optic (AFO) monitoring and maintaining a critical parts inventory.

Construction work on the two additional segments of the Bearspaw South Feeder Main, one along Parkdale Blvd N.W. between 26 St and 27 St N.W. and the other at Memorial Dr. westbound off-ramp that connects to Crowchild Tr. northbound are nearing completion.

The feeder main is a vital piece of Calgary’s infrastructure and while the urgent repair work has addressed immediate concerns, The City remains focused on long-term rehabilitation and proactive planning to ensure a reliable water distribution system for everyone.