Tetra Tech Tapped to Modernize Spillways at Two Columbia River Dams
According to Power Engineering, Tetra Tech has been selected as lead design engineer for a Progressive Design-Build spillway modernization project at two Chelan County Public Utility District dams on the Columbia River in Washington state.
Market Impact
The single-award, multi-year contract covers Rock Island Dam and Rocky Reach Dam, both located near Wenatchee, Washington. Under the agreement, Tetra Tech will provide planning, assessment, engineering, and construction services including spillway gate replacement, gate auto-hoists and controls, spillway concrete rehabilitation, structural and mechanical analyses, seismic assessments, and risk and potential failure mode analyses.
The two facilities represent significant generating capacity. Rock Island Dam, completed in 1933 as the first dam to span the Columbia River, has an installed capacity of 629 MW across 19 generators and 31 spillway gates. Rocky Reach Dam, which began commercial operation in 1961, now operates 11 generators with a nameplate capacity of 1,349 MW and 12 spillway gates. Together, they are part of what Tetra Tech CEO Roger Argus described as “the second largest nonfederal, publicly owned hydroelectric generating system in the nation.”
What It Means for Subcontractors
- Civil and concrete specialty contractors should watch for subcontracting opportunities tied to spillway concrete rehabilitation at both facilities, work that typically requires crews experienced in mass concrete repair and hydraulic structures.
- Mechanical and electrical subs with experience in gate fabrication, hoisting systems, and dam controls are well-positioned to pursue lower-tier roles under Tetra Tech’s design-build team.
- Seismic and geotechnical firms in Washington and the broader Pacific Northwest may find opportunities in the advanced seismic analysis and structural assessment phases of the project.
- The Progressive Design-Build delivery model means subcontractors who can engage early in the design phase, and demonstrate technical capability alongside construction execution, have an advantage over traditional low-bid competitors.
- Long project duration under a multi-year contract suggests sustained workflow rather than a single mobilization, giving subs reason to build relationships with Tetra Tech now rather than waiting for a single bid window.
