Slideshow | Spirit of 1899 still echoes as Falls hydropower plant gets refit of the century
January 12, 2012 · Updated 1:08 PM
Critics called it “Baker’s Folly.”
The idea of tunneling 260 feet through solid rock to install a power plant at the base of a waterfall was considered so bold as to be ludicrous to some.
But not only was the Snoqualmie Falls hydroelectric plant a success, it’s also had an amazing longevity.
It took Charles H. Baker, a visionary engineer and entrepreneur from back east, 16 months and, they say, only 35 employees to build the subterranean power plant, the world’s first. Electric lights in a cavern below the Falls proclaim the year that it all started, “1898.”
If Baker could see his creation now, he’d probably be amazed and proud.
“As he predicted, his project is still running,” said Elizabeth Dubrueil, resident historian for Puget Sound Energy, the company that operates the Falls plant today.
“This plant is still doing what he built it to do,” Dubreuil added.
While the Falls power plant is now at the midpoint of a 114-year tune-up, Baker’s concept, as well as his original four hydroelectric generators, are still at the heart of it all.
Change of the century
Above and below ground, great changes are happening at the Snoqualmie Falls.
Some of these changes will be apparent to the eye when the $200 million makeover of the Falls hydropower plant, now at its midpoint, wraps up in the spring of 2013. Others won’t be as visible, but they’ll be felt in subtle ways.
Take, for example, the mammoth piece of pipe that dwarfed Dave Jennesse, manager of the Falls project for owner Puget Sound Energy, during a recent visit. The pipe is a major new feature, but it’ll potentially affect fish and downstream river users more than anyone at the Falls.
“We’re basically circumventing the Falls,” said Jennesse, pointing out how the pipe forks.
Hydropower plants are green in most ways, Jennesse said, but they can impact fish. For example, if one of the Falls plant’s seven turbines stop working, water starts backing up from the pipe to the weir. That kind of delay can mean a lowered river level, potentially harming salmon redds, or nests.
“When you have hydro plants, you need to make sure that the fish are not harmed,” Jennesse said. That big pipe, now awaiting installation by a huge crane, is part of a safety valve.
Most of the hive of activity surrounding the Falls is for improvement of what already works. The penstocks, or massive pipes that lead water down to the generators, are being updated, as is the underground cavity in the original 1899 Plant 1.
A wider, lower weir at the mouth of the dam will reduce flood impacts in Snoqualmie, although it has generated controversy downriver over concerns that it will worsen Lower Valley flooding.
On the riverbank at Plant 1, a huge, caterpillar-tracked crane conveys loads next to a large block-house-like concrete structure, the entrance to the penstocks. Nearby, a 20-foot maw in the rock leads 260 feet down to the generator cavern, its sides stained yellow by crack-sealing epoxy.
The cavern is intact, widened in places. It’s now safer and easier for workers to enter and exit. Stairs to the surface will be added, as will a faster lift. The two-and-a-half-minute ride to the surface in a 1939 elevator will be a thing of the past.
The south bank of the Snoqualmie has changed the most. Crumbling fill was scraped from the shore, surface buildings were moved or demolished. What is left on the surface is meant to blend in to the riverbank, harkening back to the era before the plant.
On the north side of the park, Plant 2, which dates from 1910, is also noisy with jackhammers. Work on the penstocks has changed the hillside, where an even bigger crane hefts steel and concrete into position. The concrete building taking shape is entirely new; when finished, its industrial look will echo the former 1950s powerhouse.
The original Plant 2 was built in two sections, one in 1910, the other in 1956. Structural issues arising from its unusual past made it impossible to upgrade the building, so it’s being replaced entirely.
“There was much more thinking about how you get in and out of the building in the future,” Dubreuil said.
The original horizontal turbine at Plant 2 is also being replaced by a better vertical unit.
Technical upgrades at Plants 1 and 2 add an additional 10 megawatts of generating capacity to the old 44-MW system, allowing the Falls to power about 40,000 customers, 10,000 more than before.
The hundreds of workers at the Falls face much of the same types of challenges that Charles Baker’s men dealt with more than a century ago. Cliffs, underground chambers and a living waterfall are all part of the job site.
Baker had it easy in one way: All he had to do was drop items down the shaft and install them. Today’s workers had a lot of deconstruction to do first.
“It’s always easier to start from scratch than remodel,” Dubreuil said.
Today’s crew also has the environment to think about. PSE sternly limits any access to the cavern via the tailrace at the foot of the falls.
“Nobody is supposed to be out there,” Dubreuil said. Given the Falls’ cultural importance, “we have preservation standards.” That means running supplies down the shaft instead of through the back door.
Photos of the Falls hillsides from 100 years ago show a denuded landscape. Water cannons eroded the vegetation, trees were cut down. Today, Dubreuil said PSE has pursued a much more limited impact on the environment.
Another challenge is that some equipment remains in the cavern and needs to be protected from rockfall during the work.
Ease of access was one of the key reasons why Plant 2 was built downriver. But the crews working on that plant have one advantage that the workers in 1910 didn’t have: Road access. A century ago, there was no bridge. Everything had to be hauled by rail or ferry boat.
Some of the tools are the same—the coffer dams that keep the river at bay are much the same as their predecessors.
But tech has changed. The cranes are much bigger, and can reach much further than their ancestors. Materials are better; penstocks are smoother, allowing for better water flow and more power.
One big difference is in prefabrication. In the 19th century, many parts and pieces had to be built on site by resident carpenters and blacksmiths. Today, it’s much more plug and play. Drive through Snoqualmie, and you may notice row upon row of penstocks at Weber Construction’s Highway 202 yard, awaiting shipment to their final destination.
The story has been handed down that Baker relied on only 35 men to complete its task. Dubreuil finds that remarkable.
“These guys were more general tradesmen. A lot of them had a lot of useful skills,” she said. “Today’s crews, in a lot of cases, they’re very specialized.”
Today’s crew size is estimated at 140 people. Barnard Construction of Bozeman, Mont., is the main contractor among seven lead consulting companies, numerous subcontractors and suppliers.
History in the making
Part of the new vision at the Falls includes preservation of the old. Baker’s original carpenter’s shop, a century-old, steel-sided structure, has been moved alongside the wooden railway depot that once welcomed tourists to the Falls. These buildings are the core of a future in-house museum.
The former Unit 5 turbine has been raised from deep below, to be put out to pasture as an outdoor historical display.
Snoqualmie historian Dave Battey is excited about what that old turbine might inspire in young visitors.
“Kids can learn a lot just by playing around,” he said. “What will stick in a kid’s mind, when they figure out what this thing, turning here, can do? This can be amazing.”
With the entire project on track to wrap up in April of 2013, the coming year will see a lot more changes at the Falls, including the construction of a new, modern Plant 2 building and the new gatehouse at Plant 1.
“A lot of it has been behind the scenes until now,” PSE spokesman Roger Thompson said. “You’re going to see a lot of things happening.”
See even more photos
Puget Sound Energy has set up a slide show of images from its Falls hydropower project. The photos and captions can be viewed on Flickr at http://www.flickr.com/photos/pugetsoundenergy/sets/72157627000982339/
Timeline and more
Details on the project and a timeline can be found on the Puget Sound Energy webpage, here.