Where the Wallooskee and Youngs Rivers meet, the Cowlitz Indian Tribe sponsored a project to restore almost 200 acres of agricultural land to a tidal wetland complex. Like many fields in the Lower Columbia, the site was protected by a levee that prevented brackish water from entering with the tides. The levee itself was in disrepair, regularly overtopped and covered in a dense growth of invasive species.
Biohabitats worked with a diverse array of stakeholders to convert the ditched, tiled, and seeded pastureland back to a vibrant mosaic of floodplain habitats. Doing so required excavating backwater channels, breaching the levees, removing tide gates, installing a sheet pile wall to protect a highway, and adding large woody debris habitat complexity. The full restoration of the site included altering the vegetative composition as well, removing the invasive species that dominated the levy.
Biohabitats provided design-build preconstruction consultation services to a large team that included civil and geotechnical engineers, wetland scientists, and staff from Bonneville Power Administration, the Oregon Department of Fish and Wildlife, the National Marine Fisheries Service, and the Army Corps of Engineers.
Biohabitats professional services included backwater channel design layout, selecting locations for breaching the levee, producing and reviewing design plans, designing fish salvage and construction sequencing, and providing construction value-engineering and cost estimates. Biohabitats also played a key role in the project’s permitting, including assisting the team on the Biological Assessment, Environmental Impact Statement, and federal and state project permitting.