News Release

Interior to Lower Mainland Transmission Line

The transmission circuits that bring power from generation resources in the north and southern Interior of the province to the Lower Mainland and Vancouver Island are some of the most critical paths in the transmission grid. Built in the early 1970s, the circuits are reaching the limits of their capacity during periods of peak demand.

The Interior to Lower Mainland (ILM) Transmission Project will expand the capacity of these essential transmission circuits so that they can continue to reliably deliver clean and renewable energy to the Lower Mainland and Vancouver Island.

The ILM Project includes construction of a new 255 kilometre, 500 kilovolt transmission line between the Nicola Substation near Merritt and the Meridian Substation in Coquitlam and a new series capacitor station at Ruby Creek near Agassiz.

When the existing line was built in the early 1970’s, additional right-of-way (ROW) was acquired in anticipation of future growth. Thanks to this foresight, the new line will parallel an existing 500 kV transmission line ROW for the majority of the distance. Approximately 74 km of the line will require new ROW, while approximately 60 km will require widening of the existing ROW. Construction will begin once the necessary environmental and regulatory approvals are in place.

By ensuring the most efficient transfer of electricity, the ILM Project will retain energy that otherwise would be lost – enough energy to supply about 80,000 homes per year.

In selecting the ILM route, BC Hydro committed to a number of measures to minimize environmental impacts. These included:

Funding contributions to a captive breeding and re-introduction program for the northern spotted owl in order to minimize impacts to their habitat area.

Securing wetlands for a population of Oregon spotted frogs and providing the Ministry of Environment with funding to complete six years of egg mass surveys. At present, there are only a few populations of Oregon spotted frogs in B.C., all in the Fraser Valley. In 1999, they were declared an endangered species and are protected under the British Columbia Wildlife Act.


  • BC Hydro is continuing to pursue the 2014 in-service date. The feasibility of this will depend on
  • all permits being in place and the Design/Build contractorconfirming that they can meet the 2014 date.
  • The estimated project cost is $540 - $780 million.
  • There will be approximately 543 person-years of employment created through the project.

See our interactive projects map.