Snoqualmie Falls dam to be two feet lower

Puget Sound Energy can now move forward with major renovation at its 111-year-old Snoqualmie Falls hydroelectric power plant.

Federal regulators issued PSE a key amendment to the utility’s operating license for project on Monday, June 1, company officials said.

Construction work will ramp up in September, and is expected to last, in stages, through 2014.

The project will permanently lower the dam at the falls by two feet, reducing river levels in times of flood.

PSE Spokesman Roger Thompson said that with a lower dam, a severe flood would be eight inches lower.

Two buildings are being demolished, a transformer house and machine shop, both of which date from the early 1900s.

They rest on fill from excavation of the original power plant, Plant 1. The land is slowly settling, and the buildings are crumbling.

Once they are gone, the man-made bank of the river they sit on will also be removed. A new water intake will be built further upstream.

Consequently, the mouth of the falls will be some 20 feet wider.

The project adds extra 10-megawatt generating capacity to the 44-MW plant, without taking any more water out of the river.

The century-old penstocks, or pipes carrying water to the turbines, are being replaced — as is the generating gear. Plant 1’s historic turbines will remain on the job, generating power as they have always done.

A lot of love and care go into maintaining equipment that’s more than a century old, according to Thompson.

“It’s astonishing hardware,” he said.

Work on improvements to public areas and the Falls park will start first. The upper and lower parks and observation deck at the Falls will close intermittently during construction beginning this fall. New benches, lighting, signs, trails and kiosks and disabled access will be installed. Upper park work should be complete by spring 2010.

Removal of the old buildings across the river at the Plant 1 site will begin next summer.

PSE applied for the project license from FERC in 1991 and received it in 2004. The amendment was sought in 2007 following the Corps 205 Snoqualmie Flood Reduction Project completion.

A legal challenge to the project by the Snoqualmie Tribe was defeated last fall.

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