Cowlitz Falls Barrier Dam Repair Project

Shimmick is repairing and upgrading the Cowlitz Salmon Hatchery barrier dam in Salkum, WA. The project includes construction of a reinforced concrete weir infill section and concrete repairs to the existing apron and training walls. In addition, Shimmick is supplying and installing a left-entrance bulkhead and right flow deflector, supplying template for deflector embeds, and constructing a temporary system for water treatment.

The project entails inspection, repair, and reconstruction of the weir dam and apron slab, which was damaged by the existing weir’s shape and subsequent underwater hydraulic jump. The weir dam plays an important ecological and environmental role in the southern migration of salmon, steelhead, and other fish species.