Colony Construction delivers powerhouse structural steel, intake buildings, control houses, and dam-rehabilitation structural support across the US – from Pacific Northwest dams on the Columbia, Snake, and Willamette rivers to Colorado River projects and TVA-adjacent experience. Founded in 1985 and responsible for more than 700 completed projects including major Canadian hydroelectric work, Colony brings plate-girder powerhouse capability, tolerance-critical turbine-hall detailing, and cofferdam-sequenced erection experience to US hydro owners. Every frame is engineered to AISC 360-22, welded to AWS D1.1:2020, stamped by licensed US PEs, and coordinated with USACE, Bureau of Reclamation, or FERC licensing milestones. Clients pick Colony because we treat turbine-hall tolerances like mill tolerances – and because an aging-dam rehabilitation backlog of 1,500+ US dams over 75 years old cannot wait on slow-moving delivery teams.
US Hydroelectric Construction Expertise
Hydroelectric construction demands the tightest structural tolerances in the industrial steel market. Embedments for turbine units, crane runways over 200 tons for generator-stator picks, and powerhouse framing coordinated with mechanical vendors all live at tolerances typical of mill construction rather than generic building work. Colony’s hydro portfolio – including the Mayo B powerhouse in the Yukon and Dockside Green renewable-power facilities – has built the detailing discipline and erection sequencing that Pacific Northwest, Colorado River, and TVA-adjacent hydro projects require. Our engineers routinely work inside the USACE specification framework, Bureau of Reclamation construction practices, and FERC Part 12 dam-safety inspection programs, integrating as a construction partner to the prime contractor or IOU that holds the license.
Our US hydro scope spans powerhouse structural steel, intake buildings, control and switchgear houses, tailrace frame support, spillway gate and gantry structures, fish-passage building infrastructure, and dam-rehabilitation support structures. We fabricate plate girders in our shops to AISC 303 Code of Standard Practice, coordinate embedments with the mechanical OEM in Tekla, and deploy erection crews experienced with heavy picks over in-river construction sequences. The aging-dam rehabilitation backlog – more than 1,500 US dams over 75 years old under FERC Part 12 and USACE inspection – is a long-horizon demand driver our team is built to meet.
New-Build, Rehabilitation, and Aging-Dam Infrastructure
Powerhouse Structural Steel and Turbine-Hall Tolerances
Powerhouse framing around turbine-generator units must hold embedment tolerances the mill vendors specify – often ± 1/16 inch over 40+ foot bays. Colony’s detailing runs in Tekla coordinated with the mechanical OEM’s 3D model, our shops fabricate to AISC 303 with owner-accepted inspection plans, and our erection teams work to survey control integrated with the mechanical scope. The same discipline applies to generator-stator pick crane runways over 200 tons.
Aging-Dam Rehabilitation (1,500+ US Dams Over 75 Years Old)
FERC Part 12 safety inspections, USACE periodic assessments, and Bureau of Reclamation review programs drive a multi-decade rehabilitation pipeline on aging US infrastructure. Colony’s scope on these projects runs to structural support for hydromechanical rehabilitation, spillway gate and gantry replacement, powerhouse retrofits for unit upgrades, and structural assessments of existing framing under new load cases. We integrate as the structural-steel partner to the owner’s prime contractor.
FERC-Regulated Licensing and Relicensing Construction Milestones
FERC-licensed hydro projects come with relicensing construction milestones tied to the license order – fish-passage installations, flow augmentation structures, sedimentation or fish-screen buildings. Colony delivers structural scope to owner and EPC schedules aligned with the FERC milestone, with QA/QC documentation that slots into the FERC construction record.
In-River Construction Sequencing and Cofferdam Coordination
Pacific Northwest hydro construction often requires in-river work inside cofferdams on a short dry window. Colony coordinates structural erection with the cofferdam dewatering sequence, pre-assembles sub-modules for rapid placement during low-flow windows, and integrates with the owner’s fish-passage and environmental compliance constraints. The in-river season dictates schedule; our job is to be ready when the cofferdam is.
Seismic Design for Pacific Northwest Cascadia and Columbia Gorge Wind
Pacific Northwest hydro sites sit inside the Cascadia Subduction Zone – among the highest seismic-hazard zones in the US. Columbia Gorge projects face extreme wind environments layered onto that seismic hazard. Our AISC 341 seismic detailing and ASCE 7 wind-load design are routine on these projects; powerhouse primary frames, gantry structures, and intake buildings are all engineered to the site-specific hazard without generic over-design.
USACE and Bureau of Reclamation Specification Frameworks
USACE and Bureau of Reclamation projects run on their own specification frameworks – EM 1110 civil-works manuals, Reclamation design standards, and agency-specific QA/QC. Colony’s engineering and project-management teams work inside these frameworks as a subcontractor to the prime contractor on federal hydro work, delivering structural scope that passes agency inspection on the first submission.
Featured Projects
Mayo B Powerhouse
Colony fabricated and erected plate-girder powerhouse structural steel for this hydroelectric development in the Yukon, including turbine-hall framing, crane runways, and switchgear building support. The plate-girder powerhouse scope and tolerance-critical detailing transfer directly to Columbia River, Snake River, and TVA-adjacent powerhouse rehabilitation work.
Dockside Green Biomass Energy Facility
Renewable-power facility structural framing with process-parallel equipment coordination, integrated mechanical embedments, and tight schedule under a design-build model. Process-facility experience directly applicable to hydro powerhouse mechanical coordination and modern pumped-storage or small-hydro development work.
Diavik Diamond Mines
Remote heavy process-plant structural steel delivered into one of Canada’s most remote industrial sites. The remote-logistics and tolerance-critical scope mirrors what remote US hydro sites and small-hydro developments in Alaska and the Pacific Northwest demand on short construction windows.
Frequently Asked Questions
Which US hydro operators and agencies does Colony work with – USACE, Bureau of Reclamation, TVA, IOUs, public utilities?
Colony works as a structural-steel subcontractor to prime contractors and EPCs on USACE, Bureau of Reclamation, and IOU hydro projects, with Pacific Northwest public-utility (PUD) experience a natural fit. TVA facilities fall outside our 12 target states, so we reference TVA-adjacent work as experience breadth rather than an active prospecting region. Our structural-steel role plugs into the prime’s FERC, agency, or utility deliverable package.
How does Colony support the aging-dam rehabilitation backlog (1,500+ US dams over 75 years old)?
Structural-steel scope on rehab work runs to spillway gate and gantry replacement, powerhouse unit upgrades, hydromechanical support structures, and retrofit framing that accepts new load cases on existing concrete. We laser-survey existing framing, model the new structure in Tekla coordinated with the rehab mechanical scope, and sequence erection around the owner’s outage window.
What experience do you have with FERC-regulated licensing and relicensing construction milestones?
FERC-licensed projects come with construction milestones tied to the license order – fish-passage installations, flow-augmentation structures, environmental-compliance buildings. Colony delivers structural scope on owner or EPC schedules aligned to the FERC milestone, with QA/QC documentation that slots into the FERC construction record. We integrate with the owner’s licensing consultant where the milestone has specific inspection requirements.
How do you handle in-river construction sequencing, cofferdams, and fish-passage constraints in the Pacific Northwest?
Pacific Northwest in-river work runs on a short dry window inside cofferdams with strict fish-passage constraints. Colony coordinates structural erection with the cofferdam dewatering sequence, pre-assembles sub-modules for rapid placement during low-flow, and integrates with the owner’s environmental compliance team. The construction window dictates the schedule; we plan fabrication and mobilization around it.
Can Colony support pumped-storage hydro projects and new small-hydro development?
Yes. Pumped-storage hydro is a growing US segment driven by grid-scale energy storage demand, with upper-reservoir intake structures, penstock supports, and reversible-turbine powerhouse framing that share structural discipline with traditional hydro. Small-hydro development – particularly FERC-exempt projects under 10 MW – runs on compressed schedules with tight budgets where our design-build capability and plate-girder powerhouse experience is directly applicable.
Start Your Hydroelectric Construction Project
Send us your scope, schedule, and site details. A Colony estimator will review your project and reply within one business day.