Energy Box Canyon Upstream Fish Passage

Project Highlights

• Constructed a 27-pool half Ice Harbor-style fish ladder with gravity-fed, variable flow up to 300 cfs.
• Built a double cell sheet pile cofferdam and a 40-foot-high soldier pile tie-back retaining wall under challenging seasonal conditions.
• This project included a sorting facility equipped with a crowder system and a brail lift for efficient fish handling and transport.

Project Description

The Box Canyon Upstream Fish Passage project, commissioned by Pend Oreille PUD as part of a relicensing condition, aimed to enhance migration for bull trout, cutthroat trout, and mountain whitefish. The selected method was a trap-and-haul system, which required precision engineering and adaptive design to address environmental challenges such as historic run-off and extreme cold.

MacKay Sposito played a critical role by providing full-time on-site construction management as the primary liaison for all stakeholders. The project featured complex elements, including a 27-pool Ice Harbor-style fish ladder, a v-trap leading to a sorting facility, and a high-capacity gravity-fed intake system designed to function across varying tailrace elevations. Additional infrastructure included a double-cell cofferdam constructed from a flexi-float and a tall soldier pile retaining wall, ensuring structural integrity and timeline compliance.