Glenmore Dam Utility Relocation

After extensive conceptual investigations, the decision was made to relocate both the feedermain and gas line via a tunnel beneath the Elbow River, directly downstream of the Glenmore Dam.

Key Aspects and Challenges

• New 1500 mm C300 concrete feedermain and 300 mm gas line located within a 1650 mm concrete tunnel
• Five (5) vertical access shafts, varying in depth from 7 m to 31 m, required for installation of the tunnel components, for construction
• Almost 700 m of 1650 mm diameter tunnel
• Tunnel crossing 9 m below the Elbow River, and tie-ins between the new and existing feedermains on each side of the tunnel to mitigate construction risk and improve redundancy.
• Multiple high-rise utility crossings, which the tunnelling contractor elegantly resolved by proposing a revised methodology to his and the City’s benefit; revised methodology included a sloped tunnel and added in access shafts to be used for tunnel construction.
• Narrow shutdown windows; the feedermain is critical to South.