The project proposes to replace an existing 1.83 meter (m) [6 foot (ft)] wide by 1.22 m (4 ft) tall corrugated steel squash pipe, 20.12 m (66 ft) in length, which is only 33 percent passable due to a slope of 1.7 percent, with a 6.10 m (20 ft) wide x 3.96 m (13 ft) tall split box culvert 23.77 m (78 ft) in length. According to the SWIFD layers provided in the Chehalis Fish Passage Barrier Prioritization interactive mapper (March 2020) replacement of this culvert will restore unimpeded access to 1.88 linear miles of potential habitat for the Southwest Washington ESU of coho salmon and 1.74 linear miles of potential habitat for the Southwest Washington DPS of winter steelhead trout. However, according to the Washington State Fish Passage interactive mapper one upstream barrier culvert was identified on December 18, 2019. Therefore, replacement of the proposed culvert is anticipated to restore immediate unimpeded access to 1.73 linear miles of potential habitat for coho salmon and 1.59 linear miles of potential habitat for steelhead.  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 3,484 square meters of spawning area and 2,081 square meters of rearing habitat will also become accessible. The proposed project would improve fish passage, reduce sedimentation thereby improving water quality, and increase riparian cover.