Blue Crk at Spencer Fish Habitat Restoration Desig

Lewis County Public Works proposes to restore fish passage and enhance habitat for juvenile coho salmon, fall Chinook salmon, and winter steelhead trout. Fish passage designs will include development of preliminary designs for 1) the modification of a 20 ft wide by 5 ft high weir/dam (Site 981318) and the removal of a 17 ft wide by 7 ft high water diversion weir/dam (Site 980911) associated with the Cowlitz Trout Hatchery, 2) the removal of a 24 ft long bridge and replacement with a fish passable structure, 3) large woody debris structures, and 4) channel regrade.  Additional project elements will include review of and potential development of preliminary designs for a side channel to redirect flows away from roadside ditches as well as the potential replacement of existing 3 ft and 2 ft corrugated metal culverts (Site 980912 and Site 980916 respectively) to carry additional flows from side channels. The anticipated project implementation area extends from approximately 5,104 ft upstream of the Spencer Rd Bridge to 2,350 ft downstream and 770 ft east to the culvert crossing on Spencer Rd (Site 980912) that carries flows from an unnamed tributary to Blue Creek. Per SWIFD, barrier corrections will restore access to 2.22 linear miles of habitat for the Lower Columbia River (LCR) Evolutionarily Significant Unit (ESU) of fall Chinook, 3.26 miles of habitat for the LCR ESU of coho, and 3.33 miles of habitat for the LCR Distinct Population Segment (DPS) of winter steelhead trout.

The primary goal of the proposed project is to provide a habitat restoration design, that once constructed, will restore fish passage to all life stages of coho salmon, Chinook salmon, and winter steelhead trout through the lower reach of Blue Creek from river mile 0.97 to RM 2.16. The project would also provide a design to install sediment input protection measures to maintain fish passage. The greatest benefits of restoring fish passage by way of reducing sedimentation will be realized during high flow events, when the excessive height of the channel bed currently causes frequent overbank flooding and subsequent stranding of listed fish species.