Building resilience beneath the surface: Metro Vancouver’s deep tunnel water program
When it comes to ensuring clean, reliable water for a growing region of more than three million residents, Metro Vancouver is looking deep underground. The regional federation unites 21 municipalities, one electoral area, and one treaty First Nation to manage services that transcend local boundaries. It delivers the essentials that keep the region liveable: drinking water, wastewater treatment, solid waste and recycling, regional parks, air quality regulation, and housing programs.
Through this collaborative model, Metro Vancouver provides infrastructure at a regional scale that individual cities could not efficiently achieve on their own. That shared approach is now being put to the test through one of the most ambitious underground water initiatives in Canada — a network of major water supply tunnels designed to safeguard the region’s lifeline against earthquakes, climate uncertainty, and future population growth.
Metro Vancouver is investing in deep underground water tunnels to ensure clean, reliable water for over three million residents
The initiative is a cornerstone of Metro Vancouver’s long-term resilience strategy, guided by seismic risk modelling and reinforced by lessons from international earthquake events. In a recent interview, Murray Gant, Director of Major Tunnelling Projects, Project Delivery, described how the organisation is building resilience from the bedrock up. “Making sure our regional infrastructure is resilient to earthquakes is a top priority for Metro Vancouver,” Gant said. “It’s critical that our water facilities remain operational following an earthquake and that we design our infrastructure and systems to meet seismic design requirements.”
Engineering for earthquakes
The current wave of deep-tunnel investment stems directly from Metro Vancouver’s comprehensive review of seismic hazards across its water network. That assessment identified several marine crossings as both vulnerable and strategically vital for maintaining supply following a major earthquake — notably the Port Mann, Second Narrows, Cambie-Richmond, and Pitt River crossings.
Seismic risk modelling guides project priorities, focusing on critical crossings most vulnerable to earthquake damage yet hardest to repair
The Port Mann Water Supply Tunnel, completed in 2017, was the first of these deep, resilient crossings. Since then, Metro Vancouver has advanced the Second Narrows Water Supply Tunnel into the final stages of construction, while the Cambie-Richmond and Pitt River tunnels are moving through conceptual and preliminary design.
Beyond those strategic crossings, several other tunnelling projects are underway that will add significant resilience to the regional water system and provide for growth, maintenance, and minimise surface impacts. Among them is the Stanley Park Water Supply Tunnel, where construction began in December 2024 and shaft excavation is now starting.
Seismic risk modelling played a defining role in how the tunnel projects were prioritised. As Gant explained, Metro Vancouver has been focusing on improving the resiliency of key crossings to withstand a Maximum Credible Earthquake (MCE) — the most severe earthquake reasonably expected to affect the region. These are precisely the crossings that would be hardest to repair in the aftermath of a disaster, making them a logical focus for early investment. While the costs are significant, Gant emphasised that the stakes are far higher: “The cost of failure — loss of water supply to three million residents during a disaster — is far greater.”
The tunnels are designed to last more than a century and to increase overall system capacity, ensuring both resilience and long-term value. Metro Vancouver’s decision-making has also been shaped by international precedents. “Our resilience planning was influenced by earthquake events in New Zealand and Turkey,” Gant said, “which demonstrated the devastating impact of inadequate infrastructure resilience.”
Each tunnel adds redundancy and flexibility, allowing water to be rerouted and minimising single points of failure during emergencies
That focus on preparedness extends across the regional system. “It is critical that our entire water system is resilient to seismic risk, and this begins with the water supply dams,” Gant noted. Both supply dams have been seismically upgraded, and a seismic hazard and stability assessment is ongoing. Meanwhile, treatment plants, in-system reservoirs, and nearly 50 pump stations are being upgraded in sequence based on their age and vulnerability.
A more flexible and redundant network
The tunnels’ deep alignment and robust seismic design standards will fundamentally reshape how Metro Vancouver operates its regional transmission network. Beyond resilience, the projects introduce new operational flexibility, redundancy, and emergency response capabilities — essential for both routine operations and crisis management.
“Multiple valve chambers are being constructed at tunnel shaft sites, allowing operators to control and redirect water flows more dynamically,” Gant explained. This means water can be rebalanced across different parts of the region more easily, particularly during maintenance or peak-demand periods.
The tunnels provide additional transmission routes, significantly increasing redundancy. “If one pipeline is compromised, others can maintain service,” Gant said. “The new tunnels ensure backup capability and reduce single points of failure.” Each tunnel is equipped with valve chambers and backup power systems to further enhance reliability.
Deep underground placement — often in dense, stable soils or bedrock — provides protection against seismic shaking and surface disruption. “These tunnels are engineered to remain operational during and after a major earthquake,” Gant said. “In the event of a rupture or disaster, the system can isolate damaged sections and reroute water through unaffected tunnels.”
Centralized control through new valve chambers will also speed up response coordination in emergencies. Beyond emergency response, the tunnels support population growth and climate resilience. By expanding capacity and integrating seamlessly with existing infrastructure, they ensure the region can continue delivering high-quality drinking water under both normal and extreme conditions — while minimizing surface disruption to communities and the environment during construction.
Financing future-proof infrastructure
With tunnelling projects valued at more than $2 billion, Metro Vancouver has adopted a measured, long-term financial strategy to sustain its investment in resilience without imposing sharp cost increases on residents. “Metro Vancouver is ensuring the financial sustainability of its water supply tunnel program through a combination of long-term financial planning, diversified funding models, and strategic cost management,” Gant said.
More than $2 billion is being invested, supported by long-term financial planning, predictable rate increases, and potential government funding
A key part of that approach is gradual, predictable rate increases for households, spreading the cost of construction over time and avoiding sudden spikes. The utility has also deferred or reprioritized lower-risk projects to focus resources on critical infrastructure and is exploring provincial and federal grants that align with its resilience objectives, particularly for projects in high-growth or environmentally sensitive areas.
Affordability is supported by strong governance and transparent consultation. Budgets and rate impacts are reviewed annually with member jurisdictions, First Nations, and the public. Metro Vancouver’s long-term planning forecasts reinvestment needs and capital requirements, ensuring financial decisions align with system performance and community expectations.
Metro Vancouver’s governance model also ensures equitable cost-sharing. The organization is governed by a Board of Directors of elected officials from each member jurisdiction. “Water services are funded through regional utility water rates on a cost-recovery basis,” Gant explained. “Development cost charges are levied on new developments to ensure that growth pays for growth.”
Planning for 2050 and beyond
Metro Vancouver’s deep-tunnel program is not only about seismic resilience; it also addresses long-term growth and climate change. The region’s population is projected to rise by more than one million people by 2050, reaching over four million residents. This growth is central to Metro 2050, the region’s comprehensive plan for land use, infrastructure, and environmental resilience.
“The tunnel projects are part of a broader infrastructure upgrade to ensure the continued delivery of high-quality drinking water to a growing population,” Gant said. Metro Vancouver’s Water Supply Outlook 2120 study extends that view to the next century, modelling future demand under scenarios of population growth, climate variability, and seismic risk. The study confirms that additional infrastructure, including deep tunnels and expanded access to Coquitlam Lake, will be essential to avoid seasonal shortages by the mid-2030s.
The projects align with Metro 2050 and Water Supply Outlook 2120, addressing growth, seismic risk, and climate change impacts
Climate change is already influencing hydrology across the region, with changing snowpack, drought frequency, and water quality challenges. The tunnels form part of Metro Vancouver’s broader adaptation strategy, ensuring that transmission capacity and redundancy remain strong under shifting conditions.
Metro Vancouver’s earlier Port Mann Water Supply Tunnel, completed in 2017, laid the foundation for this next generation of projects. Lessons from that work have guided current and upcoming tunnels, informing design choices, construction methods, and system integration. Each new crossing extends that legacy — part of a deliberate effort to ensure the regional water system can endure and adapt through the next century. “We’ve learned from every project,” Gant reflected. “Each tunnel reinforces the value of deep, resilient infrastructure as the foundation of regional water security.”
As Metro Vancouver looks toward 2050 and beyond, its tunnelling program stands as a model for strategic resilience — ensuring clean, safe water continues to flow for generations to come.