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Energy Priest Rapids Right Embankment Improvement Project
A long, winding fenced walkway crosses a dry golden hillside toward a river and dam, with a few people on the path and rugged brown mountains in the background.
Project Location
Desert Aire, WA
Client Grant County Public Utility District No. 2
Market Sector
Project Type
  • Power Generation
Services Provided

Project Highlights

  • Provided full-time construction management and a rotating team of inspectors to support 24-hour excavation monitoring.
  • Delivered UAV mapping, quantity verification, and on-site materials testing with mobilized lab equipment for RCC work.
  • Ensured cultural sensitivity and compliance near Wanapum Village, adapting to aggregate source changes and logistics challenges.

Project Description

The Priest Rapids Right Embankment Improvement Project addresses safety and structural concerns with the existing right embankment of the Priest Rapids Dam. The central effort involves constructing a new Roller Compacted Concrete (RCC) dam measuring approximately 2,200 feet long and 25 feet high, located landward of the original embankment. MacKay Sposito was crucial in the project’s early and active phases, providing full-time construction management during pre-construction and deploying a comprehensive inspection team as work progressed.

The firm’s responsibilities extended to 24-hour excavation monitoring, materials testing, and UAV services for mapping and quantity verification. Faced with unanticipated issues, such as the unavailability of the original aggregate source, MacKay Sposito supported the shift to a commercial source and helped manage haul route logistics and RCC mix design validation. The team prioritized cultural awareness and contractor compliance with established requirements in light of the project’s proximity to the Wanapum Village.