PSE power house, floating surface collector projects enter home stretch

By Jason Miller
posted 11.9.12

Two major Puget Sound Energy projects are sprinting toward completion in Concrete. Both should wrap up at different points in 2013.

Lower Baker power house
After an unstable slope to the east of the construction site delayed the start of the new power house, the $43 million project was off and running in 2011. PSE officials now are looking at an August 2013 completion date, with no major setbacks along the way.

“We’ve been really lucky; we’re doing well; it’s going well,” said PSE Project Manager Scott Rzemien.

Construction crews have completed installation of the turbine in the turbine generator and are currently installing the generator portion. Tailrace construction is about 15 percent complete and should be finished in March 2013, said Rzemien.

“We’re preparing for startup and commissioning sometime after Jan. 1. While that’s happening we’ll complete the mechanical, electrical, and architectural systems inside the power house,” said Rzemien. “After that it’s just site work: We’ll finish grading and complete the access road work.”

The new power house is mostly underground. When it’s complete, only the top 4 to 6 feet of it will be above grade. The subterranean design is a response to the 1955 landslide that destroyed the first two power houses—Units 1 and 2—that PSE had built upstream from the current site.

The new power house will raise the power capacity of PSE’s two Baker River dams from today’s 170 megawatts to 200 megawatts, enough peak output to serve 150,000 households.

Floating surface collector
Farther upstream, a floating surface collector was launched into Lake Shannon in late July. The FSC is an approximately four-story metal box that was built on shore, then launched into the lake and floated. Its components include a net transition structure—a pyramid-shaped funnel that comes out of the box—and giant nets that extend to the lake floor and the shoreline.

In early November “we mated the net transition structure to [the FSC],” said PSE Project Manager Jim Hogan. “It’s a big milestone. It’s a huge curtain. We spread it across the lake and then slowly dropped it to the bottom of the lake. It’s a week-long operation in itself.”

Commissioning of the structure is under way, according to Project Engineer Andrea Smith with Skanska, the contractor that built the FSC. “We’re starting up the systems and making sure they’re running—fine-tuning and adding some last-minute items that PSE wanted,” said Smith. “We’re scheduled to turn it over to PSE in March 2013, and PSE will run it.”

When the FSC is functioning, it will generate a current that will fool young salmon into thinking they’re headed down the Baker River. They’ll be collected in the body of the unit, where some will be tagged. From there they’ll be transported by boat to a new, Skanska-built pier and loaded into trucks for transport downstream.

Published in Concrete Herald, November 2012

This aerial photo shows the floating surface collector being moved into Lake Shannon in late July. (Photo courtesy of Aequalis Photography.)

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