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When Vancouver is hungriest, Mica dam provides the power

Mica plant manager Morgan McLennan stands atop Mica Dam with 'reactor alley' and Mt. Nagle of the Monashee range in the background.
Mica plant manager Morgan McLennan stands atop Mica Dam, a 700-km drive northeast of Vancouver. In the background is Mica's "reactor alley", which supports the voltage for the 500-kilovolt transmission lines that make their way to the southern coast of B.C. In the background is Mt. Nagle in the Monashee range.

Built inside a mountain, 1970s powerhouse adds 5th and 6th generating units

Morgan McLennan has no "Mini-Me" clone, nor will he pose for a photo with his right pinkie at his mouth. But there’s a standing joke in some BC Hydro circles that McLennan is "Dr. Evil", the James Bond movie-style villain played by comedian Mike Myers in the Austin Powers movies.  

After all, McLennan is ruler of an underground lair, literally built inside a mountain and reached via a walk through a creepy underground tunnel. And he has access to enough power to rule the world…

… Or at least enough to supply electricity to Vancouver and the B.C. south coast at its hungriest, such as on a cold December evening when we’re all doing laundry and the dishes while watching the Canucks on TV.

McLennan is plant manager for BC Hydro's Mica powerhouse, essentially five hydroelectric turbine generators – with a sixth ready for action later this year – housed in the bowels of a mountain located along Mica Dam a 90-minute drive north of Revelstoke. The reality is that McLennan is as professional as Dr. Evil is weird, and he had reason to smile last month as the powerhouse's massive crane moved the head cover for Unit No. 6 to a spot above the last turbine, then was lowered into place.

When it becomes operational later this year, the sixth and last generating unit at Mica will add more than 500 additional megawatts of electricity to BC Hydro's grid. Combined with another 500 megawatts from up-and-running unit No. 5, the additional capacity at Mica will be enough to power another 80,000 homes.

"It makes me proud everyday, coming in to work," says McLennan, a Winnipeg native who also worked 18 years at BC Hydro's GM Shrum Generating Station on the Peace River. "I'm really proud of the crews we have working here now – they're really good. And we're coming up on six years without a lost time injury – that's a pretty good record for a facility of this size, with all the work going on here."

One of the residential buildings at Kinbasket Lodge work camp below Mica dam on Lake Revelstoke
One of a collection of buildings at Mica Creek Townsite, the work camp that's a home away from home for regular workers at the Mica dam site. Numbers at the camp hit 400 as a flood of employees and contractors came to Mica to install the final two generating units in the dam's powerhouse.

Workers at remote Mica dam learn to live away from home for extended periods

When there are no projects going on, the nearby Mica worker camp – known as Mica Creek Townsite  – will have a population of about 70. But during the Mica switchgear, generator 5 and 6 projects, there have been as many as 400 at the camp – some on four-days-on, three-days off rotations, others staying for 10 days and then leaving the camp to drive home for a four-day break.

The workers get quality meals, including a weekly steak and prawns dinner, and take advantage of boating and fishing on the Kinbasket Reservoir. But it's a whole different scenario than the one McLennan experienced up north at GM Shrum and the WAC Bennett Dam, where crews commuted daily to their homes in nearby Hudson’s Hope.

"I think the remoteness of Mica makes it different," says McLennan, a camp regular whose home is a two-hour drive away at Sicamous. "Here, the crews live all over the Thompson-Okanagan and commute into the camp here. Once you're here and working, you're seeing these guys at work, breakfast, lunch and supper.

"When you're here, you're living it 24-7."

Crane in Mica powerhouse carries generator No. 6 cap to its place above turbine
The head cover of the No. 6 and final generating unit in the Mica powerhouse is moved by crane across the powerhouse in May. The powerhouse was built in the 1970s, but the final two of six generating units - representing more than 500 megawatts of additional power - were not added until this year.

‘You just put a machine in the hole, and you have power’

The Mica dam itself owns the mind-blowing stat – in rising more than 240 metres above bedrock, it’s the second tallest dam in North America and higher than any building in Vancouver. But it’s the powerhouse that is arguably the more impressive engineering feat.

When it was finished in 1973, it was the largest underground powerhouse in the world: 54 metres high, 24 metres wide and 237 metres long. On top of that, there were myriad tunnels to be drilled, including penstocks (tubes to carry water from the reservoir to the turbines), access and emergency exit tunnels for those working at the powerhouse, and tailrace tunnels, for the water to escape below the dam after running through the turbines.

Drilling and blasting at the time involved more than a little experimentation, and competition between crews bent finding the fastest way through the glitter-specked 'mica' rock. A book on BC Hydro'’s dam-building history, 'Voices fromTwo Rivers', details a raucous "hole through party"” after the power intake tunnels were completed in October, 1971. As the alcohol flowed, a few fights broke out, the RCMP were called in, and a shift boss recalled a miner emerging — cut over the eye and bleeding from his nose — but thanking the superintendent for "the best party in years."

With safety as a top priority at BC Hydro, there's no evidence of such bedlam today, but as you emerge from the rough-hewn access tunnels into a large, comfortable office space and then into the massive, well-organized powerhouse, you get an appreciation for why those crews in the 1970s may have partied so hard. Burrowing into that mountain ranks as a monumental achievement, and the work included drilling of two penstocks that remained capped until generating units No. 5 and 6 were installed this year.

"For me the amazing thing is that the infrastructure is already there," says BC Hydro's Will Kirkness, who schedules contractors working at Mica. "We're adding 1,000 megawatts to the system without changing anything.

"You just put a machine in the hole and you have power."

Francis turbine for Mica Dam on truck in Kansas full size
Francis turbine destined for Mica's powerhouse is shown en route from Germany, on a highway in Kansas. The final stage of the 6.45-metre wide turbine's journey was by barge down the 200-kilometre-long Kinbasket Reservoir above Mica dam.

Mica turbines manufactured in Germany, Japan and the Soviet Union

The 6.45-metre wide stainless steel turbines at Mica are so large – at 137 tonnes they each weigh as much as four humpback whales – that there aren't many places on the planet capable of producing them. That's why the No. 5 and No. 6 turbines came across the Atlantic and then across North America on two separate journeys from Germany.

Of Mica's original four turbines installed in the 1970s, two were manufactured by Hitachi in Japan, while the other two were products of the Soviet Union, from the Leningrad Metal Works plant.

The 'Voices From Two Rivers' book details the trepidation BC Hydro felt after a first look at the Soviet turbines when they arrived in the 1970s. The Leningrad plant may have been in operation since 1857, but one BC Hydro inspector said the turbines were so crude they looked "like someone had manufactured them in his basement."

Once in place, however, they performed better than the Japanese turbines. "We all had to step back, shake our heads and say, 'Well, I guess they know what the hell they were doing.'"

The more efficient new No. 5 and No. 6 turbines from Germany will each help generate a bit more power than the old ones, and No. 5 is already proving to have a personality of its own. You might call it the introverted new kid in town.

"It’s very smooth – you can hardly tell it's running compared to the other ones," says McLennan. "When I went down there when we first put it on, I was standing there and didn’t know whether it was running. I had to walk over to the control board to see, and it was putting out 500 megawatts."

Shot from below Mica Dam showing Kinbasket reservoir and surrounding peaks.
A view of Mica dam, one of the world's largest earth-filled dams, from below Kinbasket Reservoir. Buiilt more than 240 metres above bedrock, the dam is the second highest in North America and is taller than the tallest building in Vancouver.