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Return to power: Snoqualmie Falls hydro plant, park renewal project enters final lap | Photo gallery
Byron Kurtz has to shout to be heard over the noise of the huge machine that’s above, beneath and around him.
“I was here when they took it off,” Kurtz says—June 15, 2010, when the Falls’ Plant 2 turbines went silent. “I was here when they put it back together,” and the juice started to flow again. This green-painted original unit switched on April 17.
Behind Kurtz, the generator and turbine extend through a three-story concrete structure. This morning, it’s producing about 23 megawatts of electricity—almost full power.
Plant 2 has been here for 103 years. But there’s a lot that’s new today.
“It feels good,” Kurtz says “It’s different.”
Above, workers fix components of the new turbine at Plant 2.
The differences, some subtle, some more obvious, can be seen at Snoqualmie Falls as the reconstruction project that began here in 2009 enters its final months. Puget Sound Energy is spending $200 million on a once-in-a-century upgrade to the hydropower stations at the Falls—115-year-old Plant 1, located inside a rock cavern 250 feet below the lip of the waterfall, and the 103-year-old Plant 2, built at surface level to the west of the Falls overlook.
The project, which modernized the equipment and structures of the generating plant, and also updated the Falls park, are set to wrap up this September. When finished, the changes make the park better for visitors, allow PSE to generate some extra energy, and decrease the plant’s impact on the environment.
One floor down from Kurtz, below the level of the river, the roar of water throbs through massive concrete walls. Huge blue-painted pipes, as wide as a small car, convey water on its journey around an inactive turbine. These are the bypass valves, explains Dave Jennessee, who manages the construction project for PSE.
“Before, if we shut a unit down, water would have to wait, and back-up over the Falls,” he said. Tokul Creek, just downstream, is a spawning bed for Chinook salmon and steelhead. If the water drops, the redds, nests of salmon eggs, could be exposed and die. These vast pipes keep that from happening.
Up the hill, a set of sensors monitors flows in the penstocks—the pipes that carry water into the power plant. If flows don’t match—perhaps an earthquake could break the pipes—emergency gates close automatically back at the Falls entrance to make sure the hill isn’t flooded out.
Both hydropower plants are now part of a more intricate system that balances the needs of the river ecosystem with power generation.
“We’re a run-of-the-river operation… We’re allowed to take a certain amount of water out of the river,” says Jennesse. “But we have requirements for how much water goes over the Falls. We need both plants to meet our obligations.”
Above, a cut in the ridge near the Peregrine Viewpoint acts as an emergency release valve for water entering Plant 2;
A new ‘Falls’
Few sightseers ever check out the Plant 2 gatehouse, due west of the Peregrine overlook. Originally built in 1910, the gatehouse is fed by a 1,200-foot concrete-lined tunnel that goes under the Salish Lodge. Past the gate, water drops down a steep hill via huge pipes called penstocks into the powerhouse.
Up here, from the gatehouse, Snoqualmie Falls is visible through a notch cut in the rock, which Jennesse explains is a pressure valve. If the Plant 2 generators malfunction, metal gates close and a wall of water rises through the penstocks. The flow backs up and out through the rock cut, creating a second, smaller version of Snoqualmie Falls, tumbling 200 feet. The same effect would happen in extremely high river conditions. A small spume of spray flowing off the cliff is visible today, and is part of this system.
A PSE employee stands near sidewalk art in the Falls park, which includes the Snoqualmie word for “hike,” above.
The upgraded park will give people new ways to experience the Falls, and a major new addition, one of the last to the site, is the lower park.
From a parking area with 40 spaces—three for buses—and an education area, a raised boardwalk will lead between the huge pipes and the powerhouse to a river path.
A starway of stones lead down to a kayak put-in downriver from the plant outflow.
Back at the crest of the hill, a trail entrance that leads to the lower park is in final stages of construction, and is changing by the day.
“We wanted to emphasize that this is the start of the trail,” says Tony Fuchs, a consulting research scientist with PSE. The trailhead feature includes a restored wetland mini-park with a bench, pavement art, interactive kiosk and bear-proof garbage cans. It’s a place to stop before or after the hike to the bottom of the Falls.
At the Falls Park, the overlook includes several concrete-mounted metal rings. They’re for rescue teams who have to rappel off the cliff.
Nearby, kiosks are waterproof, made of porcelain, and show the past, present and future of the Falls in word and art. Other exhibits include a waterwheel from one of the underground turbines. Sidewalks are heated to keep ice away in winter.
Above, workers descend to Plant 1 via crane through the new equipment shaft.
Work proceeds apace at the older Plant 1, which is deep underground. New elevator and equipment shafts connect with the surface. The tour group watches as workers descend in a capsule dangling from a crane.
“If we ever have to bring equipment off, there’s a removable section of the roof,” so cranes can lift heavy gear up and out, explains Jennesse.
Along the shore, the brown-colored river wall is dotted with polka dots—drainage holes to ensure that groundwater from the Ridge hillside above doesn’t cause any problems.
At the crest of the Falls, the weir is now two feet lower and 30 feet wider.
Near the new Plant 2 gateway, a special claw to lift logs away from the gates, guards the entrance to the dark tunnel of water. Other mechanical arms sweep smaller debris from the gate and rake them into a metal trough, resembling a playground slide, that discharges below the weir. The sticks await a strong flow to wash them over the Falls.
When finished, the plant will generate about 54 megawatts of power, enough for a town of 40,000 people. It’s a small but key piece of Puget Sound Energy’s grid.
Once all the construction crews are gone, about 10 permanent PSE employees will remain behind to run the plant and tend the grounds. A mini-museum will greet guests on the historic Plant 1 side.
Completion is expected by mid-August. A party and ribbon cutting follows in September.
Rings set in concrete in the upper park act as anchors for rescue teams who must descend the cliff.
Josh Reynolds and Dave Jennesse stand at the overlook of the Plant 2 gatehouse at Snoqualmie Falls. Below is Plant 2, originally built in 1910.
The Plant 2 gatehouse, above and below.
Penstocks lead down the hill from the Plant 2. The heavy concrete pentagon absorbs the thrust of the falling water.
Workers explore the future kayak put-in near Plant 2;
Water bypass valves below the Plant 2 turbines; This room is below the level of the river.
Dave Jennesse by one of the pipes.