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New 255-km transmission line to take on rugged terrain

BC Hydro employees on planning hike
BC Hydro project manager Melissa Holland and geotechnical lead consultant Terry Rollerson hike at 2,000 metres above sea level looking for a place to bring the line through.  

Interior to Lower Mainland Transmission line vital to meeting growing demand

Michelle Martin
bchydro.com

After more than 35 years doing overhead transmission engineering and design work, Garry Barnett knew that he was up for a challenge when the Interior to Lower Mainland Transmission Line Project (ILM) came back on his radar about five years ago.

"Five hundred kilovolt lines are often technically challenging, and this one goes through some of the most rugged terrain in B.C. Some of the route has been logged in the past, some areas are slide zones, and many areas are so steep or engulfed in forest that they can only be accessed by helicopter. One area even goes 2,000 metres above sea level!" he says.

"When I flew over the route at Cascade Creek (Maple Ridge area), I said, 'Woah. It's some wild and wooly territory out there.' I had to hike it to understand our route options."

Connecting generation to population

Barnett first became involved in the line's route design in 1978, then again around 1983 and once again in the late 1990s. Previously, the need to build the line couldn't be justified. This time around, however, the demand for the line is so strong that construction will begin just about as soon as regulatory approval is granted.

"The line will allow for load growth in the Lower Mainland," explains project manager Melissa Holland. "We're not seeing new generation close to the load centre; Mica 5 and 6 are coming on line in 2014 and so we have to have more transmission to bring power from the Interior to the Lower Mainland.

"Our planners have identified the need to add significant capacity to the transmission system by 2014 between the Nicola Substation near Merritt and the Meridian Substation in Coquitlam."

The Interior to Lower Mainland transmission project will cost an estimated $540 million to $780 million and is part of $6 billion in capital project spending planned by bchydro in the next three years alone.

As B.C. has grown, so has our need for clean electricity. Our goal is to manage our growth through conservation and the smart use of power, but BC Hydro also needs to renew our infrastructure to meet the needs of future generations. That's why we're investing now to ensure a legacy of clean, reliable power for British Columbians for the next 50 years and beyond.

Sometimes, a hike's the best thing

Like Barnett and other core team members, Holland knows the route on the map, on foot and by helicopter.

"It is 255-kilometres long, goes through six bio-geoclimatic zones, and passes through the traditional territory of 67 First Nation bands and tribal councils," she says.

When built, ILM will parallel existing 500 kilovolt transmission lines for the majority of the way. Approximately 74 kilometres of the route requires new right-of-way and 60 kilometres requires widening of existing rights-of-way.

"Challenges have arisen from the line passing through the habitat of the endangered Northern Spotted Owl and the Oregon Spotted Frog," says Donna McGeachie, communications and consultation manager with BC Hydro. "We have committed to supporting the Spotted Owl captive breeding program, and for the frogs we purchased 88 acres of wetlands to preserve their habitat."

Additionally, BC Hydro has been consulting with 60 First Nations and seven tribal councils regarding the potential impacts of the project and has signed a series of Impact Benefits Agreements with various bands.

When construction begins, it will take three to four years to complete. Currently, the target in-service date is set for 2014.

A look back to the 1970s

Wally Lyle, manager of BC Hydro's construction forces during the early 1970s, shared his memories of building the original transmission lines that connected the Columbia system to the Lower Mainland in the BC Hydro history book 'Gaslights to Gigawatts'.

"There was a lot of brainpower behind the 500 kilovolt system… We did a lot of things that a lot of people didn't think were possible and those helicopter pilots were damned brave and were willing to try things, like stringing five miles of pea line.

"We had the big Sikorsky helicopters that could lift an entire tower and bring it into place. The crew on the ground would be there already. Everything was premeasured by instrument; they built a foundation, and down came those towers. We put those things down in unbelievable terrain."

Michelle Martin is a communications advisor with BC Hydro employee communications.