A Major Breakthrough!

A remarkable tunnelling achievement has been completed beneath the Skwelwil’em Squamish Estuary and Monmouth Mountain in Howe Sound.

FortisBC has achieved tunnel breakthrough on the Eagle Mountain – Woodfibre Gas Pipeline (EGP) Project, connecting two separately excavated sections to create a continuous, nine-kilometre underground tunnel between Squamish and the Woodfibre LNG site at swiy̓át.

The tunnel is a critical piece of infrastructure for Woodfibre LNG. Once pipeline installation is complete, it will support the transportation of natural gas to our facility, where the gas will be transformed into LNG for export to global markets.

A globally significant engineering achievement in Howe Sound

The scale and complexity of the tunnel is significant.

From the Woodfibre LNG side, the tunnel descends from approximately 50 metres above sea level to about 25 metres below sea level at its deepest point, travelling through a substantial granite massif beneath Monmouth Mountain before rising again toward the BC Rail portal in Squamish.

Construction required two custom-designed tunnel boring machines to navigate two dramatically different geological environments: approximately 5 km of hard rock and 3.9 km of soft ground.

To put the tunnel’s length into perspective, walking the nine kilometres from one end to the other would take roughly two hours.

Protecting the Skwelwil’em Squamish Estuary

Early plans for the EGP Project contemplated an overland route that would have required ground disturbance within the Skwelwil’em Squamish Estuary Wildlife Management Area. Through engagement and project planning, Sḵwx̱wú7mesh Úxwumixw (Squamish Nation) emphasized the importance of avoiding surface impacts to this culturally and environmentally significant area. The project was subsequently amended to include the underground tunnel.

The result allows the pipeline to pass beneath the 673-hectare Wildlife Management Area, which provides habitat for sensitive plants, fish and wildlife, while avoiding surface disturbance within the estuary.

The tunnelling approach also reflects requirements of the Squamish Nation Environmental Assessment Agreement and years of collaboration and engagement with Sḵwx̱wú7mesh Úxwumixw.

Connecting Woodfibre LNG

For Woodfibre LNG, tunnel breakthrough represents another important piece of the infrastructure required for future operations coming together.

The EGP Project will expand FortisBC’s natural gas transmission system between Coquitlam and the Woodfibre LNG site. Woodfibre LNG will receive its natural gas through this pipeline system where it will be liquefied into LNG and then exported to global markets.

With tunnel excavation now complete, crews will remove the remaining tunnel boring machine and prepare the tunnel for pipeline installation.

The milestone reflects years of planning, technical expertise and collaboration by FortisBC, Sḵwx̱wú7mesh Úxwumixw, contractors and the many people involved in bringing this complex piece of infrastructure to life.

Read more about the tunnel breakthrough from FortisBC on Talking Energy.