When Project planning started, Trans Mountain developed routing principles to guide our decisions. The primary focus of pipeline corridor planning is safety – for landowners, the environment and communities.

Community input and environmental, engineering and economic studies have ensured, the new pipeline will follow the existing right-of-way for 73 per cent of the route. An additional 16 per cent will follow existing utility corridors and the final 11 per cent of the new pipeline will be built away from the existing pipeline to accommodate urban development such as houses and businesses that’s happened since 1953.

The map below shows the existing Trans Mountain right-of-way corridor, as well as the approved expanded pipeline corridor and the lands proposed to be crossed by the pipeline.

Planning Principles

In planning the pipeline corridor, safety is our primary focus — safety for landowners, the environment and communities. We also consider current land use, the environmental conditions, and various engineering conditions and work to find the most efficient route with the least impact.

Determining the Right-of-Way

Pipelines are installed within a strip of land known as the right-of-way. Before the right-of-way is selected, studies take place in a determined assessment corridor to identify potential routes. These assessment studies focus on finding the best route for the new pipeline, so it can be built to minimize impacts. It is important to note  the assessment corridor is for the purposes of environmental impact assessment (EIA) studies and doesn’t reflect the ultimate width or footprint of the  construction or new line.

Once we determine the best route, we identify the centreline. The pipeline will be placed on or around the centreline (depending on the number of lines). There’s a 30-metre safety zone on either side – this is the pipeline right-of-way.


In addition to the assessment studies, extensive stakeholder engagement is carried out to identify concerns, issues and suggested improvements to the route. Stakeholder feedback resulted in numerous changes to the route.