Background - 2024 Bearspaw South Feeder Main Repairs

The City will be moving ahead with the Bearspaw South Feeder Main (BSFM) Improvements Project, with construction planned to begin on the first stage in Spring 2026.  You can learn more by visiting the Bearspaw South Feeder Main improvements project page.

An Independent Review Panel on the Bearspaw South Feedermain, lead by Siegfried Kiefer, is making steady progress and remains on track to conclude its work by the end of Q4, 2025. The Panel's report will be presented to Council in early 2026. For additional questions, please reach out to The City’s media relations online at newsroom.calgary.ca or call 403-828-2954.

We are planning further investments in water infrastructure designs that work to improve system reliability and reduce the risk of future feeder main issues.  The Bearspaw South Feeder Main Improvements Project is an important piece of his work; it will add steel pipe, parallel to the current concrete pipe and over time, this new pipe will take over service from the current line.  Following last year’s feeder main break, this work is being expedited to ensure reliable water service for Calgarians and surrounding communities—today and as our population continues to grow.  We also have other water distribution projects underway, including:

 The North Calgary Water Servicing Project

The South Calgary Water Servicing Project, which is in early development. This project will provide remaining system redundancy to the Bearspaw South Feeder Main and two other feeder mains.  This project would move water to south Calgary from the Bearspaw Water Treatment Plant and is planned to be complete by 2031.

Crosstie Feeder Main project

This project will improve the redundancy of the feeder main network in northeast Calgary and improve system pressures in Saddle Ridge, Taradale, Martindale and Falconridge. This feeder main extends along Country Hills Blvd from Coventry Hills Blvd to 60th Street NE and will be constructed by 2029. 

The cost for the repair of the initial break and repair of 29 additional pipe segments was about $38.2M.

Calgary gets its water from two water treatment plants: the Glenmore Water Treatment Plant, on the Elbow River, and the Bearspaw Water Treatment Plant, on the Bow River. 

The Bearspaw South Feeder Main, which distributes treated water from the Bearspaw Water Treatment Plant, is the largest feeder main in our network.  

Water is drawn from the rivers and is treated at either the Glenmore or Bearspaw Water Treatment Plant.

After it’s treated and is safe to drink, water moves through large pipes called feeder mains to underground storage reservoirs. (Unlike the Glenmore Reservoir, which stores untreated river water, these underground storage reservoirs contain treated water).

From there, water flows through smaller distribution mains to homes and businesses.

Several different materials are used:

Pre-stressed concrete cylindrical pipes, such as the Bearspaw South Feeder Main, have a composite construction made up of a steel reinforcement cable sandwiched between layers of concrete. 

These pipes can last a long time, as much as 100 years in ideal conditions. 98% of Calgary’s feeder mains, which are critical pipes in our distribution system, are in good or very good condition. This is aligned with the target we have set for our system. 

While the risk of a pipe break was deemed lower based on available data and modeling, The City did take action to reduce the impact of a failure. Investments in replacement air valves reduced risk factors to operations.

The City has also invested in the reliability of the two water treatment plants and the broader pipe network to improve the capacity of the system to deliver water even when a failure occurs.

The 2011 and 2021 Water Long Range Plans also included future investments that will improve the redundancy of the system. An Emergency Response Plan for the Bearspaw South Feeder Main was prepared to quickly respond to a failure and maintain service while a repair was executed. This plan also included our critical parts inventory.

The most recent maintenance work happened in the spring of 2024, including replacement of air valves and the installation of an acoustic monitoring device. Routine field checks on valve chambers are also performed regularly.

Several test shutdowns were undertaken in the winter of 2023 and spring 2024 in preparation for a full condition assessment planned for December 2024.

98% of our water distribution system is rated as being in “good” or “very good” physical condition. This rating is due to The City’s ongoing condition assessment and maintenance programs, which help to identify and address potential problems.

We are unable to physically inspect all existing infrastructure every year, so physical condition is based on a combination of asset characteristics, physical observations, operational knowledge, and experience of known issues. 

The City has an annual inspection program for its pipe assets, including feeder mains. The logistics of inspecting over 5,000 km of pipe means that inspection data is supplemented with modeling of pipe condition. Inspection data are used to calibrate this model, which also incorporates factors of pipe material, pipe age, known condition, failure history, location, operating pressures, soil parameters and cathodic protection. 

The model, along with an evaluation the assets hydraulic importance in the system, ease of repair, and by understanding the social, environmental, and financial consequences of potential failures, is used to guide inspection efforts and identify candidates for the pipe replacement program. Pipe breaks are used to continually improve the modeling results.

There are two types of acoustic monitoring available for this type of pipe. External acoustic monitors are discreet sensors mounted to the outside of the pipe. They pickup events within the pipe (possible wire breaks) but are low-resolution compared to the fiber optic monitoring. They can tell us if an event occurred near a sensor, but they cannot tell us which pipe section has experienced the event. 

The second type of acoustic monitoring is fiber optic acoustic monitoring. Fibre optic cable is installed inside the pipe and is connected to a data acquisition system which can accurately identify the location of an event. Along with the baseline condition, data collected from the electromagnetic inspection can continuously monitor the condition of the pipeline so we can take appropriate action when the wire break count exceeds a threshold.