Project Location
Desert Aire,
WA
Client
Grant County Public Utility District
Market Sector
Project Type
- Fish Facilities
Services Provided
Project Highlights
- Installed a new top spill fish bypass system for migrating salmon.
- Modified three spillways, including gates, ogees, aprons, and extended concrete piers.
- Conducted 24/7 construction and inspections to meet in-water work window requirements.
Project Description
The Grant County Public Utility District implemented a top spill bypass system to support downstream salmon migration at the Priest Rapids Dam. This project entailed significant modifications to three spillways, including adjustments to the gates, ogees, and aprons. Prototype fish passage equipment required relocation to facilitate the new system.
MacKay Sposito acted as the owner’s construction representative, delivering inspection and quality control services. Major construction efforts included building a temporary breakwater to enable underwater concrete placement for apron extensions, partial demolition of existing infrastructure, and structural modifications such as raising the height of spillway ogees and extending concrete piers. Due to stringent in-water work window restrictions, the project required sustained 24/7 operations and inspections to maintain schedule and quality standards.