Cle Elum Dam Fish Passageway

Michels Construction, Inc. was selected to design/build the earth retention system for a 20-foot-wide fish passage structure for the Cle Elum Dam. After reviewing several options, Michels Construction’s design team recommended a shotcrete lagging design as the most time- and cost-effective solution.

The project included the installation of 102 880mm fully cased soldier piles to depths ranging from 35 to 95 feet, 222 tiebacks at an average depth of 70 feet, and 31,000 square feet of shotcrete lagging. Due to the steep slope, the project was divided into six different benches to provide level pads for the drill and crane to work.

The entire project was located in a lakebed. Crews had to wait until the lake was drawn back, exposing the first bench, before they could begin. The project was completed on a tight schedule due to seasonal rise in water levels. When the dam was built in 1933, fish passages were not constructed, causing the decline of a diverse habitat. The new structure is expected to benefit several fish species.