Manson Construction

Owner: U.S. Army Corps of Engineers, Portland District
Contract Amount: $31,990,000
Joint Venture: Kiewit Pacific/ Manson
Location: Columbia River, North Bonneville, WA
Project Duration: 08/2002-12/2003

This joint venture project involved constructing a bypass channel at Bonneville Dam intended to increase the survival rate of juvenile migrating fish.

The work on the new open flow channel included rock removal, excavation and the underwater placement of precast concrete elements and tremie underwater concrete fill. The finished product was a 3,000-foot-long, high-velocity concrete chute, with 25-foot-high walls, that safely transports fish through the powerhouse and into the new channel outfall.

This project won an Excellence in Concrete Award from the Oregon Concrete and Aggregate Producers Association and received an “Outstanding” Performance Evaluation from the U.S. Army Corps of Engineers, Portland District.