DESCRIPTION
The project proposes to replace an existing 3-foot diameter
by 31-foot long fish passage barrier culvert, that is 33 percent passable due
to a water surface drop, with an approximate 24-foot wide by 10-foot tall by
70-foot long precast concrete split box culvert. Additional Construction will
include a channel regrade and placement of streambed material within the
culvert and channel regrade area.
Replacement of this culvert is anticipated to restore
immediate access to 1.36 linear miles of habitat for the
Southwest Washington (SWW) Distinct Population Segment (DPS) of winter
steelhead and 1.22 linear miles of habitat for the Southwest Washington (SWW)
Evolutionarily Significant Unit (ESU) of coho. There are no barriers upstream
of this culvert.
The proposed project would improve fish
passage, sedimentation, and water quality as well as provide access to areas
with high quality riparian cover.
The proposed restoration project will replace an approximately 3-foot (ft) diameter by 31-ft long culvert, which has a precast concrete inlet and corrugated metal outlet, with a 24-ft wide by 12-ft tall by 70-ft long split box culvert at Lucas Creek Road milepost 4.24 in Lewis County, Washington. The barrier to be replaced, which conveys an unnamed tributary to Lucas Creek, is only 33 percent passable due to a water surface drop of approximately 2 ft. The "Prioritized Chehalis Barriers - May 2020" layer in the Chehalis Fish Passage Barrier Prioritization interactive mapper (May 2020) identifies the existing barrier as a Priority 2 barrier. Replacement of this culvert is anticipated to restore unimpeded access to 1.22 linear miles of potential habitat for the Southwest Washington Evolutionarily Significant Unit of coho salmon and 1.36 linear miles of potential habitat for the Southwest Washington Distinct Population Segment of winter steelhead trout.There are no barriers downstream or upstream of this culvert. According to the Lewis Conservation District, who performed a full stream habitat survey of Lucas Creek and its tributaries in 2002, the proposed project will also restore access to 2,588 square meters of spawning area and 1,299 square meters of rearing habitat will also become accessible.
