Second Narrows Water Supply Tunnel construction substantially complete

Metro Vancouver announced it has substantially finished construction on the Second Narrows Water Supply Tunnel.

“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.”

The Second Narrows Water Supply Tunnel lies 30 metres below the bottom of the Burrard Inlet, east of the Ironworkers Memorial Bridge, between Burnaby and the District of North Vancouver. The tunnel was excavated through a variety of ground conditions using a slurry tunnel boring machine, and replaces three water mains built between the 1940s and the 1970s that are vulnerable to damage during an earthquake and are nearing the end of their service lives.

The new water supply tunnel is 6.5 metres in diameter, just over one kilometre long, and contains three new large-diameter steel water mains. The mains are designed to withstand a one-in-10,000-year earthquake while delivering more than one million litres of drinking water every day to Vancouver, Burnaby, Richmond, New Westminster, Delta, and parts of Coquitlam and Surrey.

“We are incredibly fortunate to live in a region with great drinking water, but what is less obvious is the work it takes to deliver consistent service,” said Brad West, chair of Metro Vancouver’s Water Committee. “The investment that Metro Vancouver makes in delivering large-scale infrastructure that is resilient, reliable, and adaptive to our growing population is one of the things that has made our region one of the most livable in the world.”

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. Metro Vancouver has also begun restoring Second Narrows Park (also known as Montrose Park), where work took place on the Burnaby side.

In 2024, the project received the Tunnelling Association of Canada’s Canadian Project of the Year Award, which is presented to a team that has significantly contributed to a project in Canada that has demonstrated the highest level of engineering skill and shown insight and understanding of underground construction. In 2025, the project was also presented with the Award of Excellence from the Association of Consulting Engineers — BC Chapter in the Municipal and Civil Infrastructure category.

Metro Vancouver supplies high-quality drinking water each day to more than three million people, over half of BC’s population. This project is one of several new regional water supply tunnels being designed to meet current seismic standards, ensuring the reliable delivery of water in the region in the event of a major earthquake.

Metro Vancouver has consistently delivered some of BC’s largest public infrastructure projects. Today, Metro Vancouver has over 300 large projects in its capital plan, all designed to meet the needs of a rapidly growing population.

Featured image: (Metro Vancouver)