The Mckenzie Siphon is a crucial part of the City of Calgary’s wastewater system, transporting wastewater to the Fish Creek Wastewater Treatment Plant.

The siphon consists of an inlet chamber and two underground pipes that allow wastewater to flow freely to the treatment plant and then to the river, preventing backups in both low and high flow conditions.

The siphon is primarily located in Fish Creek Provincial Park near the community of Deer Run, just north of the Fish Creek Wastewater Treatment Plant. It extends south under the Bow River and ends near the community of Mckenzie Lake.

Built in 1980, it now needs upgrades which will enhance the system’s integrity and capacity to prevent breaks and sewage backups for homeowners and businesses during heavy rainfall.

Construction is anticipated to begin in summer 2026 and is expected to be completed in Fall 2027. Most of the upgrade work involves trench excavation to install two new sanitary pipes. Microtunnelling will be used to install the siphon pipes under the river. 

This project is separate from the Fish Creek Wastewater Plant Upgrade project, but will contribute to efficiently transporting wastewater to the plant.

• Provides resiliency to our wastewater transportation infrastructure through installing these new pipes and using the existing pipes as redundancy.  
• Adds capacity to the wastewater infrastructure to address current and future population growth.
• Ensures wastewater flows freely to the treatment plant and then to the river, preventing backups in both low and high flow conditions.