Chehalis Basin Mitigation Bank
Hanaford Valley, Centralia, WA
Cascade designed the Chehalis Basin Mitigation Bank to complement and provide additional lift to the adjacent Big Hanaford Creek Mitigation Site by restoring, rehabilitating, and enhancing riverine wetlands and floodplain function in the Hanaford Valley.
Cascade developed the site plans and the Mitigation Bank Instrument and worked with the client to navigate the agency approval process. Restoration actions included site grading and ditch filling to reconnect stream channels and improve hydrologic functions, placement of aquatic and terrestrial habitat structures (large wood), weed management, and re-vegetation with native species.
Because the site contributes additional area to an existing mitigation project, available wetland functions assessment methods were unable to characterize the functional lift. Cascade instead developed a project-specific wetland functions assessment methodology. Technical review of the Mitigation Bank Instrument was completed in 18 months.
Site construction was completed in the Spring of 2018.