COWI strengthens Metro Vancouver’s water future 

New Westminster/Surrey, BC — COWI, a leading global engineering consultancy in North America, is approaching the final stages of its work as construction engineer on the Annacis Water Supply Tunnel — a transformative infrastructure project designed to ensure safe, reliable drinking water for generations to come. 

Commissioned by Metro Vancouver, the 2.3 km long, 2.6 m diameter steel water main runs approximately 50 metres beneath the Fraser River, connecting the City of New Westminster and the City of Surrey. The project is part of Metro Vancouver’s broader strategy to upgrade and modernize critical water infrastructure, including five new water supply crossings designed to remain fully operational even in the aftermath of a major earthquake. Construction is being carried out by Traylor Aecon General Partnership. 

The Annacis Water Supply Tunnel exemplifies Metro Vancouver’s commitment to building infrastructure that can endure future seismic and climate-related challenges. As one of five new deep under-river water crossings planned across the region, the tunnel is specifically engineered to remain fully operational after a major earthquake. By positioning the 2.3-kilometre steel main approximately 50 metres beneath the Fraser River, the project avoids surface vulnerabilities such as flooding, river scour, and marine loading, ensuring long-term protection of the water supply. 

“Resilience is at the heart of this project,” said Nedim Alca, Market Director, 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.” 

“This crossing represents a critical link in Metro Vancouver’s long-term plan to secure a reliable water supply, even under the most demanding conditions. As we reach the end of excavation, we’re proud to see a design that began on paper now becoming an integral part of the region’s infrastructure — one that will quietly serve millions of people every day, well into the next century.” 

COWI’s role has encompassed the full design scope for slurry wall shafts and base slabs for the north and south shafts, tunnel lining design, and ground improvement strategies for break-in and break-out. The team has also provided engineering design management and ongoing support throughout construction, ensuring seamless integration and delivery at every stage.