Willamette Falls Fishway Repair

Project Details

Prime Contractor: Advanced American Construction
Owner: Oregon Department of Fish & Wildlife
Location: West Linn, OR | August 2020 – November 2020

Advanced American Construction was the successful low bidder on The Willamette Falls Fishway Repair project, solicited by the Oregon Department of Fish & Wildlife (ODFW). The project consisted of replacing a failed concrete apron, foundation repairs, concrete repairs, joint sealing, shotcrete stabilization, and installation of a stainless steel tension system.

The project had two primary work locations. One above and one below Willamette Falls on the historic West Linn Papermill site. The massive industrial site created significant challenges for access and material movements. AAC’s marine assets played a key role in overcoming the challenges.

On the downstream site, AAC utilized a ramp barge to move equipment, materials and a drilling subcontractor’s equipment to the site. The drill subcontractor set up and drilled 7” diameter micorpiles to secure a foundation for the existing fishway. Once complete, AAC set reinforcing, forms and poured a concrete pile cap over the new micropiles. AAC’s subcontractor also placed shotcrete over another fishway foundation surrounded by gabion rock baskets in order to stabilize the location.

Repairs to the fishway on the downstream side included cutting relief joints in the concrete flume, installing and torqueing tension brackets to minimize thermal expansion on the fish ladder, installing a joint sealant system in the fishway and general concrete repairs.

The upstream work involved removal and repair of a failed concrete apron on the dam surrounding Willamette Falls. AAC mobilized a 100 Ton crane barge as there is no access from land. The existing damaged fishway was demolished and the site was prepared for concrete work. Due to the significant challenge with access to the site, AAC mobilized a concrete batching operation on barges to pour back the concrete apron.

All work on this contract was performed in a highly sensitive environmental location without any environmental issues, safety incidents or injuries.