Bearspaw South Feeder Main
Background
The Bearspaw South Feeder Main is the largest in Calgary’s network, and distributes a significant portion of the city’s treated water supply. The feeder main experienced a break on June 5, 2024.
Since then, 29 pipe segment repairs have taken place to support the stabilization of feeder main and the pipe has undergone an investigation to gain an understanding of the conditions that lead to the failure.
- Preliminary findings of the Pipe Investigation
- Condition update on how the pipe is responding to the recent repairs
- Mid-Cycle Adjustments to support the Bearspaw South Feeder Main and redundancy projects
- Preliminary Findings of the Pipe Investigation presented at Council
- Additional repairs to two segments of the Bearspaw South Feeder Main complete
- The pipe is stabilized
- Full Report of Pipe Investigation Findings presented to Infrastructure Planning Committee (IPC)
- Resiliency for Bearspaw South Feeder Main
- North Water Servicing Options
- South Water Servicing Options
- Response report
Pipe investigation
The purpose of the Pipe Investigation, undertaken 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.
From these findings, the report indicated that there was not one specific factor that led to the failure of the feeder main in June.
Preliminary findings
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.
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.
Next steps
The final Pipe Investigation report will be presented at the Infrastructure and Planning Committee on December 11.
Repair and construction
Short term repairs on the Bearspaw South Feeder Main are now complete. The pipe has stabilized and is responding well to the 29 repairs.
| Repair | Need | Start date | Completion date |
|---|---|---|---|
| Feeder Main Break | Original Feeder Main Break emergency response and repair. | June 5, 2024 | June 16, 2024 |
| 5 Emergency hot spots | Emergency hot spots identified with the original feeder main break requiring immediate repair. | June 14, 2024 | June 27, 2024 |
| 21 Planned urgent repairs | 21 segments identified needing urgent repair through further investigation. | August 26, 2024 | September 22, 2024 |
| 2 Planned urgent repairs | 2 segments identified needing urgent repair not located in an area requiring city-wide water restrictions. | October 16, 2024 | November 26, 2024 |
Next steps
The City is currently reviewing options for long term rehabilitation of the feeder main. Findings from the Pipe Investigation will support this work. Next steps for long-term rehabilitation will be shared in 2025.
October/November 2024 Bearspaw South Feeder Main repairs
The latest repair work on the Bearspaw South Feeder Main is now complete. We are now in the process of returning the feeder main to service. You may notice water cloudiness or a chlorine smell during this process, however your water remains safe to drink.
Crews are demobilizing and cleaning up at site 3, located at Brownsea Dr N.W. at the bottom of the Bev Longstaff Pedestrian Bridge ramp. This will result in a single lane closure on westbound Memorial Drive N.W. until mid-December and the nearby pathway at the pedestrian bridge will remain closed until mid-December. Both timelines are approximate.
Visit the construction page updates