The new Metro Vancouver water supply tunnel is 6.5m in diameter, just over 1km long, and contains three new large-diameter steel water mains. The mains are designed to withstand a one-in-10,000-year earthquake and deliver more than one million litres of drinking water a day to Vancouver, Burnaby, Richmond, New Westminster, Delta, and parts of Coquitlam and Surrey.
The tunnel lies 30m below the bottom of the Burrard Inlet, east of the Ironworkers Memorial Bridge, between Burnaby and the District of North Vancouver. It was excavated 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.
“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,” said Mike Hurley, chair of Metro Vancouver’s board of directors. “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.”
With the tunnel now substantially complete, Metro Vancouver will start connecting 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 Second Narrows Water Supply Tunnel is expected to be fully in service by 2028.
In 2024, the project won the Tunnelling Association of Canada’s Canadian Project of the Year Award. This year, it received the Award of Excellence from the Association of Consulting Engineers – BC Chapter in the Municipal and Civil Infrastructure category.
