TBM advancing Metro Vancouver’s US$1.4bn seismic-resilient water tunnel

Closeup of Vancouver, British Columbia, Canada. Image: Adobe Stock

The Annacis crossing, valued at CA$288 million ($208 million) and led by the Canada-based Traylor-Aecon General Partnership, will deliver a 2.6m diameter steel water main positioned 50m below the riverbed between New Westminster and Surrey municipalities.

Designed to endure a “one-in-10,000-year” earthquake, it is the longest of the region’s planned crossings and a critical element of Metro Vancouver’s long-term plan to safeguard drinking water for more than 2.5 million residents.

“Resilience is at the heart of this project,” said Nedim Alca, market director for Cowi in North America.

“What makes this milestone so significant is not just the completion of another tunnel, it’s the culmination of years of collaborative design, innovation, and precision engineering to meet the region’s future water needs.”

Denmark-based Cowi, serving as construction engineer, said it is nearing the end of its design and engineering support scope. This included work for the slurry wall shafts and base slabs for the north and south shafts, tunnel lining design, and ground improvement strategies for the tunnel boring machine’s break-in and break-out.

At peak, the project has employed 120 workers and achieved progress of about 15m per day using a slurry tunnel boring machine dubbed ‘Anna.’

Excavation began in 2022 with Anna’s breakthrough expected in 2027 and commissioning by 2028.