Estuary Restoration

Estuary Restoration2018-09-07T23:29:20+00:00

Project Description

The Columbia River estuary is roughly 150 miles long, bordered by Washington to the north and Oregon to the south. This unique ecosystem contains diverse freshwater and saltwater wetlands, shaped over centuries by riverine and tidal forces. This area is critical habitat for many salmon, steelhead and other aquatic species in the Columbia Basin. All Columbia Basin salmon must migrate through the estuary on their way to the ocean, feeding and growing along the way. Some species, including Chum and Chinook salmon, rear for an extended period in the estuary. Wetland and open water habitats in the estuary have been dramatically impacted over the last two centuries by shoreline development and hydroregulation by dams.  Inter-Fluve has been working to reconnect historically disconnected floodplains to increase quality habitat and support estuarine ecosystem function.

These former tidal wetlands at Kerry Island were impacted by diking, ditching, culvert installation, grazing, and vegetation clearing. We removed levees to restore wetland ecosystem conditions and functions.

Levees were breached at Kerry Island, reconnecting floodplains to the estuary.

Levee breach with pilot channel connecting the estuary to mature high marsh.

Construction equipment accessed the site by barge to minimize impacts to existing wetland vegetation.

The Wallacut River flows into Washington State’s Baker Bay near the mouth of the Columbia River (Pacific Ocean seen in the distance). Restoration efforts at the site included levee removal to reconnect tidal channels, sloughs and wetlands to the estuary.

Existing floodplain along the Wallacut River.


Four levee breaches reconnected the East Fork Lewis River to a 450-acre tidally-influenced floodplain wetland.


Bridges constructed over the breaches maintained access along a county trail.