By rosebell
With 6.5m in diameter and just over 1km long, the new Metro Vancouver water supply tunnel has reached substantial completion on Second Narrows Water Supply Tunnel by a Traylor Bros and Aecon joint venture.
In order to withstanding a one-in-10,000-year earthquake and delivering more than one million litres of drinking water a day to Vancouver, Burnaby, Richmond, New Westminster, Delta, and parts of Coquitlam and Surrey, this tunnel contains three new large-diameter steel water mains.
Locating 30m beneath the bottom of the Burrard Inlet, east of the Ironworkers Memorial Bridge, between Burnaby and the District of North Vancouver, this tunnel was dug through a variety of ground conditions using a slurry TBM, and replaces three water mains built between the 1940s and 1970s that are vulnerable to seismic damage.
According to Mike Hurley, chair of Metro Vancouver’s board of directors: “Building this tunnel under the Burrard Inlet was a massive project and is another great example of the critical infrastructure that Metro Vancouver delivers for this region. For a sense of scale, this tunnel was large enough to drive a truck through – and now it holds three separate water mains that will increase capacity and ensure we can continue supplying water following a major earthquake.”
Currently that the tunnel is substantially completed, Metro Vancouver is going to commence linking the new water mains to the existing water supply system. Work on these tie-ins will occur on both sides of the Burrard Inlet, and each connection is expected to take several months to complete. The scheduled date for completion of the Second Narrows Water Supply Tunnel is 2028.
While the winner of Tunnelling Association of Canada’s Canadian Project of the Year Award in 2024 was this project, this year it received the Award of Excellence from the Association of Consulting Engineers – BC Chapter in the Municipal and Civil Infrastructure category.
