A massive new piece of the Metro Vancouver’s water infrastructure network deep below Burrard Inlet is now complete.
Metro Vancouver issued a release Monday morning confirming a 1.1-kilometre tunnel linking North Vancouver to Burnaby is now finished.
“Completing this tunnel is an important milestone in this project and a remarkable testament to the innovation that is being used in Metro Vancouver to bring clean drinking water from the North Shore to the rest of the region,” said Sav Dhaliwal, chair of Metro Vancouver’s board of directors.
The Second Narrow Water Supply Tunnel will eventually replace two older water mains, built in the 1940s and 1970s. Both are nearing the end of their service lives, and if there were to be even a moderate earthquake, the damage would leave many residents of Burnaby, New Westminster and Surrey parched.
To dig the tunnel, contractors had to first drill out a 50-metre-deep shaft straight down from Metro Vancouver’s works yard in Maplewood. On the other side of the Inlet, a 100-metre shaft was dug out from Montrose Park. Crews then burrowed a 1.1-kilometre tunnel between them.
It’s the first tunnel in Canada to be drilled with a Slurry boring machine. The machine itself, which was nicknamed Lynn Marie by its operators, is 135 metres long with a 6.69-metre cutter at the business end.
With the tunnel excavation complete, crews will start installing new water mains – one 1.5 metres in diameter and two 2.4 metres – along with new valve chambers.
“Metro Vancouver is constantly upgrading its water supply system to maintain the quality and reliability of the region’s excellent drinking water, and to make the system more resilient,” said Malcolm Brodie, chair of Metro Vancouver’s water committee.
Metro Vancouver started pre-construction on the $445-million project in 2018. It is not expected to be fully online and coursing with potable H2O until 2025.