When most people in Metro Vancouver think about major tunnelling projects in the region, they probably think of transportation corridors and not water pipelines.
That could be because transportation corridors are more visible and have a greater daily impact on surrounding residents and businesses.
Business owners in the Broadway corridor, for example, have loudly protested to governments about how Broadway Line construction disrupted street traffic and hurt their businesses. They wait in vain for compensation.
Similarly, Delta commuters have for years lobbied governments to replace the George Massey Tunnel because they say it is inadequate to meet the region’s growing population’s transportation needs.
Less controversial tunnel projects have fallen below many residents’ radars.
Nonetheless, a series of ongoing major tunnel projects across the region aim to secure residents’ access to clean water, particularly after a severe earthquake.
“Replacing water lines, and sewer mains, and stuff like that, is fairly standard and routine, but Vancouver has its main water-delivery lines sitting in pipes that are on the seabed, which makes them highly susceptible to failure in the event of an earthquake,” University of British Columbia (UBC) engineering professor Erik Eberhardt told BIV.
He said the water pipes across the Fraser River and Burrard Inlet seabeds have long been partly buried, and are in loose sediments, which means they are at risk of being torn or twisted apart during earthquakes.
“If Vancouver was to just go with the status quo of what was designed 50 years ago, we'd be highly vulnerable,” he said.
Governments recognized this risk, and started acting by funding bored-tunnel replacements, back in the aught years. The plan is to have an ongoing series of major water-tunnel crossings.
“What’s most interesting is the proactiveness of these projects,” Eberhardt said. “It's a string of projects that the Metro Vancouver Regional District is doing in terms of thinking about water security.”
Workers launched the kilometre-long, $240-million Port Mann Water Supply Tunnel project in 2011. They completed it four years later, thereby alleviating the risk for those living south of the Fraser River that their water supply could be disrupted.
That water-supply tunnel was bored about 30 metres below the Fraser riverbed and was built between two 60-metre-deep vertical shafts. An 80-metre-long tunnel-boring machine launched work in February 2014 and was removed about 18 months later.
Work then launched on the 1.1-kilometre Second Narrows Water Supply Tunnel in May 2019. Estimated to cost $286 million, it is east of the Ironworkers Memorial Bridge, between North Vancouver and Burnaby.
The Second Narrows Water Supply Tunnel was also built between two shafts – one 60 metres deep in Metro Vancouver’s works yard in North Vancouver, and the other 110 metres deep in a part of Second Narrows Park.
Workers lowered a boring machine into the North Vancouver shaft and pointed it to tunnel 30 metres under Burrard Inlet until it reached the exit shaft on the waterway’s south side.
Final work on that project is slated for later this year, although it could take years to fully integrate the new infrastructure into the region’s water-distribution system.
The region’s third water-tunnel boring project – the longest to date – launched late last year and is dubbed the Annacis Water Supply Tunnel.
The planned $450-million, 2,350-metre-long, 4.5-metre wide tunnel is slated to be carved about 50 metres below the Fraser River, between River Road in Surrey and Quebec Street in New Westminster.
Construction on a planned $379-million tunnel beneath Lost Lagoon in Stanley Park, to Chilco Street, is expected to launch later this year, said Connor Langford, the sa国际传媒 tunnels team leader at Mott MacDonald, which is the prime engineering company contracted by Metro Vancouver for the project.
“That project will not be excavated with a boring machine,” he told BIV. “The new tunnel that's going underneath Stanley Park will be excavated using what is called a roadheader, which is a mobile piece of equipment that moves back and forth, to the heading. It's got a head on it that has a bunch of picks, and it spins and you just chew through the material.”
Future water tunnels related to the region’s water supply are also slated to include one that is part of an expansion to the Coquitlam Lake Water Supply Project.
“There's also the Cambie-Richmond Water Supply Tunnel, which is going into preliminary design,” Langford said.
“There's probably three or four years of design, and then it will go into construction as well.”
Transportation tunnels set to ease traffic congestion
Rapid transit and vehicle-based tunnel projects aim to make it easier for residents to get around.
The 5.7-kilometre, $2.8-billion Broadway Subway Line project is set to open in 2026.
It contains an elevated 700-metre stretch extending from VCC Clark Station to a tunnel portal near Great Northern Way. Six new stations then dot the line up to Arbutus Street, where the tunnel would at least temporarily end.
TransLink is studying a future expansion of the line to UBC.
Work is also on the horizon for an eight-lane tunnel between Delta and Richmond, which workers would build by first digging a deep trench and then dropping large concrete slabs into the trough.
That new tunnel is set to be about 40 metres upstream from the 65-year-old George Massey Tunnel, which would stay open until the new tunnel is operational.
The future tunnel is set to be made from six tunnel elements. Each element would weigh approximately 60,000 tonnes and be 130 metres by 45 metres, or about the size of a football field, according to project documents.
The tunnel elements are to be made on Deas Island and stored there until tugboats guide them into position.
Workers would first lay cables to span the river to secure the tunnel elements before those large hunks of concrete are lowered into place.
Workers would place tanks filled with water inside the tunnel elements to make it easier to lower them into position.
They would then add gravel to the tunnel’s sides, to secure it, and put rocks on top to complete the cut-and-cover work.
The province has shortlisted three groups of companies to potentially win the bid to work on the project. The plan is to announce the winning group this spring.
BIV tried contacting executives at some of those companies but they declined to comment because they have not yet won the bid to perform the work.
Shortlisted bidders are, in alphabetical order:
-Cross Fraser Partnership, which includes:
• Bouygues Construction sa国际传媒 Inc.;
• Fomento de Construcciones y Contratas sa国际传媒 Ltd.;
• Pomerleau sa国际传媒 Inc.;
• Arcadis sa国际传媒 Inc.;
• Boskalis sa国际传媒 Dredging; and
• Marine Services Ltd.
-Daewoo-GS JV, which includes:
• Daewoo Engineering and Construction Co., Ltd.;
• GS Engineering and Construction Corp.;
• Hatch Ltd.; and
• Ramboll A/S, and
• Fraser River Tunnel Constructors, which includes:
-GS Engineering and Construction Corp.;
• Acciona Infrastructure sa国际传媒 Inc.;
• Aecon Constructions, a division of Aecon Construction Group Inc.;
• Flatiron Constructors sa国际传媒 Ltd.;
• Strukton Immersion Projects B.V.;
• AECOM sa国际传媒 Ltd.; and
• Tunnel Engineering Consultants VOF
