Construction on new 1.4-km-long tunnel in Stanley Park begins in 2024

Diagram of the future Stanley Park Water Supply Tunnel. (Metro Vancouver Regional District)

There will be some short-term pain for Stanley Park visitors and West End residents for the long-term gain of the rest of Metro Vancouver and its critical supply of drinking water.

To date, Metro Vancouver Regional District has built water supply tunnels across the region generally with relatively little public attention due to the non-disruptive locations of their project construction sites.

Moreover, tunnelling for water infrastructure projects generally attracts less attention compared to subway tunnels, such as the current tunnel boring project for SkyTrain Millennium Line’s Broadway Extension.

But there will likely be a fair bit more awareness with the forthcoming Stanley Park Water Supply Tunnel Project, which is now set to begin construction in late 2024 for completion in 2029. Planning and public consultation first began in 2016, and construction was originally expected to begin in 2021.

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On Monday evening, Park Board commissioners approved the measure directing Park Board staff to negotiate with the regional district on the land use agreement to build the new tunnel, and a compensation package for the construction disruptions and long-term impacts. The potential financial details of the compensation package are not publicly known at this time.

Construction process of the existing 1930s-built water main in Stanley Park. (Metro Vancouver Regional District)

Map of the routes of the existing and future replacement water main in Stanley Park. (Metro Vancouver Regional District)

Map of the regional water mains across the First and Second Narrows, including the existing link from Stanley Park. (Metro Vancouver Regional District)

This new north-south tunnel will replace the existing 1930s-built water main tunnel beneath Pipeline Road and Tunnel Trail.

This has become a priority replacement project, with leaks of the existing tunnel growing in occurrence, including a major leak in 2016 and a minor leak earlier this year. As this is a high-pressure, high-flow water main, a major rupture of the existing pipe, potentially resembling a geyser, could cause significant damage and risk public safety.

This water main is a key conveyance system for the water supply that comes from the North Shore reservoirs and the Seymour-Capilano Filtration Plant. It specifically fulfills the water supply needs for Vancouver, Richmond, Delta, and Tsawwassen.

The new replacement water main will parallel the existing water main route, and require the excavation of three deep tunnel shafts. This seismic-resilient tunnel will have a width of 2.6 metres and a length of 1.4 km.

Stanley Park Water Supply Tunnel construction process. (Metro Vancouver Regional District)

Artistic rendering of the construction process of the Stanley Park Water Supply Tunnel. (Metro Vancouver Regional District)

The south shaft will be located on green space just south of Lost Lagoon, next to the intersection of Chico and Alberni streets.

As the name suggests, the centre shaft will be roughly mid-way on the new tunnel route, located at the Stanley Park Works Yard, which is located near the Rose Garden, just off Pipeline Road.

The centre shaft site will serve as the staging area for the two tunnel-digging operations travelling to the south shaft and north shaft. The digging will involve using conventional drilling techniques, and not a tunnel boring machine like the method chosen for previous major water main projects.

The north shaft will be located on green space in an area where Stanley Park Drive and Pipeline Trail meet. At this location, the new tunnel will connect to the existing water main tunnel beneath Burrard Inlet.

The new tunnel will be built deep under Stanley Park at depths of 35 metres to 50 metres within bedrock to provide added seismic resiliency, unlike the shallow depth of the existing tunnel from its cut-and-cover construction nearly a century ago. The southernmost segment of the new tunnel will be built directly beneath Lost Lagoon.

The three main construction sites will temporarily use a total of 4.4 acres of Stanley Park’s land area. Some trees and park amenities will be removed, some pedestrians and pathways will be temporarily closed or detoured, and some vehicle parking lots will be closed throughout construction.

Construction site plan for the south shaft of the Stanley Park Water Supply Tunnel. (Metro Vancouver Regional District)

Construction site plan for the centre shaft of the Stanley Park Water Supply Tunnel. (Metro Vancouver Regional District)

Construction site plan for the north shaft of the Stanley Park Water Supply Tunnel. (Metro Vancouver Regional District)

A 200-metre segment of Stanley Park Drive next to the north shaft site will be narrowed from two vehicle lanes to one shared lane for both vehicles and cyclists throughout the years-long construction process. This past spring, Stanley Park Drive reverted to its pre-pandemic configuration of two vehicle lanes from the decision to remove the temporary bike lane that occupied one vehicle lane.

There will also be significantly more truck traffic on the area’s streets, with the trucks using Davie Street, Denman Street, West Georgia Street, Stanley Park Causeway, and Pipeline Road. This includes the use of the roundabout entrance into the park off West Georgia Street onto Pipeline Road.

“Our population continues to grow, and so do our water demands. Upgrades are definitely necessary because our current infrastructure is aging out, and our pipelines no longer meet our demands. I’m glad ABC took out the temporary bike lane before this project started,” said ABC commissioner Jas Virdi during the public meeting.

Artistic rendering of disruptions of the Stanley Park Water Supply Tunnel’s south shaft construction site next to Lost Lagoon. (Metro Vancouver Regional District)

Alignment of the route for the new Stanley Park Water Supply Tunnel. (Metro Vancouver Regional District)

About 0.7 acres of the park will be permanently used for ground-level buffer areas to directly protect infrastructure and the footprint of two small buildings containing valve chambers that control the flow of water.

Additionally, under the land use agreement, there will be permanent restrictions on what can be built on top of the new tunnel in Stanley Park. As a measure to protect the infrastructure, the municipal government cannot build any structure or plant replacement trees on any part of the tunnel’s statutory right-of-way, nor can it dig or excavate in the area. Any changes to the area must receive the regional district’s permission.

The regional district currently estimates the project will carry a cost of $340 million, which is funded by water connection user fees. This budget includes covering the complete cost of restoring roadways, pathways, and green spaces.

To accommodate the project, there will be removals of the existing biofiltration area and the animal hospital, and a realignment of the entrance into the Stanley Park Works yard.

Construction activity on the north and south shaft sites will occur generally between 7:30 am and 8 pm on weekdays and 10 am to 8 pm on Saturdays, with no work on Sundays and holidays. The construction hours for the central shaft site, where tunnelling will begin, has yet to be determined.

“I work as a water engineer, so I’m acutely familiar with this topic and how important water infrastructure is. I’m glad we’ve been able to talk publicly tonight about that importance so that everybody is aware of how we’re planning for the future, the next 100 years,” said ABC commissioner Laura Christensen.

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