The collector had to be built within the footprint of the existing dam and fish facility.
Cowlitz Falls north shore collector
Location: Randle, Lewis County
General contractor: The Natt
Owner/developer: Tacoma Public
Primary designer: Tacoma Power
The Cowlitz Falls Dam, owned by the Lewis County Public Utility District, is located in the Cascades 13 miles north of Mount St. Helens. The dam sits in a narrow canyon across the Cowlitz River, where it has served as a power-generating station and fish-collection facility since 1994, aiding in the trucking of fish around the three major hydropower plants on the river.
During its first 15 years of operation, downstream migrant juvenile fish runs were unacceptable, necessitating a project that could improve the salmon runs.
The north shore collector was a major fish facility project constructed by Tacoma Power on the north shore of the river, designed to improve fish passage return from 50 to 95 percent. It included a fish entrance, reservoir pump-back system, fish collection structure, fish screens and bypass flume, with all elements having to be constructed within the footprint of the existing dam and fish facility.