Mattawa, WA
Priest Rapids Dam Right Embankment Improvements
Enhancing dam safety and protecting communities along the Columbia River. The IMCO project team monitored for potential dam failures 24 hours a day, seven days a week, while excavating behind the existing embankment











After years of planning and additional years of dedication, challenging scope, and inspiring teamwork, all major construction at the Priest Rapids Dam was completed in September 2023. The Priest Rapids Right Embankment Improvement project replaced the existing earthen dam, added reinforcement to the right bank of the river to address the stability of the embankment near the Priest Rapids Dam facility, improving the safety of the neighboring Wanapum Indian tribal village below, and enhancing earthquake safety. A new roller compacted concrete (RCC) dam with a short connecting embankment and secant pile cut-off wall was tied into the existing embankment. The RCC dam was constructed on basalt bedrock downstream from the existing embankment. This was an incredible accomplishment by a dedicated team and dozens of partners.
Owner
Grant County PUD No. 2
Contract Amount
$60 Million
Duration
2021 - 2023
Construction Services
Design-Bid-Build