MATTAWA, WA — Stantec announces the successful completion of the Priest Rapids Right Embankment Improvement Project. This critical infrastructure project, undertaken in collaboration with Grant County Public Utility District No. 2 (Grant PUD) and IMCO General Construction, enhances the safety and resilience of the Priest Rapids Dam, which is now able to withstand a 7.1-magnitude earthquake.

Located in Mattawa, Washington, the Priest Rapids Dam plays a crucial role in impounding water for a hydroelectric powerhouse with a rated capacity of 950 megawatts. Over time, concerns arose regarding the seismic resistance of the dam’s right embankment. To address this issue, Grant PUD initiated the Priest Rapids Right Embankment Improvement Project. Stantec’s team designed and constructed a downstream replacement dam, with the new structure mitigating potential liquefaction risks associated with the existing dam’s foundation.

Despite the challenges posed by the project’s complexity, the team managed to stay ahead of schedule and the project was completed a month early. The dam was designed and constructed using roller-compacted concrete (RCC), an alternate construction method for concrete dams that offers many advantages. Stantec has prepared designs for more than 25 RCC dams and rehabilitation structures, including gravity, thick-arch, and buttress dams.

“We are thrilled to have successfully completed the Priest Rapids Right Embankment Improvement Project ahead of schedule,” said Mario Finis, Executive Vice President of Energy & Resources at Stantec. “Our collaboration with Grant PUD exemplifies our commitment to dam safety and community resilience. The project’s success was the result of a strong partnership spanning years of planning and dedication.”