Hydropower & Dams

Douglas County PUD contracted IMCO Construction to build Washington State’s first large-scale hydrogen production facility, which will use water and power from the Wells Dam facility to produce hydrogen through an electrolysis process. Hydrogen does not emit carbon and...

IMCO completed remediation work at a hydroelectric dam near Bliss, Idaho. The facility, built in 1950 on the Snake River, required improvements to an area downstream of the spillway to prevent erosion. This design-build project focused on safety and...

IMCO installed two 41-foot wide radial gates on the main dam spillway of Thompson Falls Dam. The new radial gates replaced the existing flashboard system and provide Northwestern Energy with additional automated spill capacity. The radial gates were installed...

Built in 1961, Oxbow Fish Hatchery is located on the Oregon bank of the Snake River near the Hells Canyon National Recreation Area. The hatchery serves as a trapping, holding, and spawning facility for summer steelhead and spring Chinook...

This project included major concrete structural repairs to the spillway at the Rock Island Dam. Working over an active spillway, performing an incredibly high-risk task, required careful safety planning and daily coordination with dam operations. Work included demolition of...

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,...

This project won the ENR Northwest Best Project award and went on to win the national competition, the ENR Best of the Best Project in the small project category. Boundary Dam is located on the Pend Oreille River near...

This project involved improvements to the floating trash boom system at Rocky Reach Dam in Wenatchee, Washington. The trash boom system is designed to prevent debris from entering the dam. IMCO crews disconnected the existing cable from the upstream...

IMCO upgraded the 109-year-old turbines and generators in the Madison Powerhouse owned by NorthWestern Energy. The original powerhouse building remained in place while four new turbine-generator units were installed.  The new generating units were updated to a modern design, moving...

This project involved the removal and disposal of an existing tailrace buoy, its mooring system, and anchor, along with the placement of five district-provided buoy systems to improve dam safety for Chelan County PUD. Work at Rocky Reach Dam...

The Stoney Gate Valve Replacement project for the U.S. Army Corps of Engineers (USACE) replaced the original 100-year-old filling culvert gates at the large lock chambers of the Hiram M. Chittenden Locks, also known as the Ballard Locks. IMCO...

This remote project improved fish habitat in the Sultan River, enhancing productivity and survivability for both local and anadromous fish species. The work included tunneling into solid rock at the side of Culmback Dam and constructing a 700-foot water...

IMCO installed two 41-foot wide radial gates on the main dam spillway of Thompson Falls Dam. The new radial gates replaced the existing flashboard system and provide Northwestern Energy with additional automated spill capacity. The radial gates were installed...

This project made improvements to the spillway gates at the Albeni Falls dam for improved operations in sub-zero winter weather. IMCO crews removed 10 spillway gates, replaced the seals with an anti-frees bulb, and installed a de-icing spray system...

The Priest Rapids Hatchery Renovation project provided extensive upgrades to an existing hatchery to improve reliability and ease operation, maintenance, and monitoring of Chinook salmon rearing.   All construction work had to be strategically phased to avoid impacts to the...