Airport Levee Improvements

Improvements to the Chehalis-Centralia airport levee include elevating the height of the existing levee and raising a portion of Airport Road to provide 100-year flood protection for the Chehalis-Centralia Airport, local businesses, and a portion of I-5.

 
 
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Airport Levee Improvements

Improvements to the existing airport levee would be made by increasing the height by between 4 and 7 feet. If the existing levee is raised by 7 feet, a change to the extent and location of the northwest corner of the levee could be necessary to avoid interference with the glide path to the active runway; otherwise, no change to the extent or location of the levee would be proposed. In addition to raising the existing levee, 1,700 feet of Airport Road would be raised to meet the raised airport levee height along the southern extent of the airport, and all utility infrastructure would be replaced, terminating at the West Street overcrossing approach. Short-term impacts from construction of the Airport Levee Improvements would include limited excavation, clearing, and filling required for elevating and extending the levee. No construction would occur immediately adjacent to the active channel of the Chehalis River. For a majority of the elements of the environment, the Airport Levee Improvements would result in no long-term adverse impacts. Adverse impacts would primarily be minor in nature, except for moderate impacts due to increases in the flood extent upstream and downstream of the levee, moderate impact on groundwater from disruption of the groundwater flow regime within the footprint of the levee, and the potential loss of fewer than 5 acres of wetlands and moderate to significant impacts on cultural resources. The Airport Levee Improvements would reduce flood extents in portions of the Chehalis River floodplain, resulting in beneficial effects to water resources, land use, transportation, public services and utilities, and environmental health and safety.