Dec. 20, 2019 Floodplain Redesign

Delivering Downstream Benefits for All

Cobblestones crunch under a dusty yellow excavator dragging a 20-foot length of tree by its roots. The grappling arm weaves the log between two cottonwoods and into the river, where upset water raises its voice in response.

This deliberate logjam is one piece of a plan to restore a functional floodplain along a three mile stretch of the North Fork Touchet River in southeast Washington. Boulders and woody debris will influence the river’s flow while creating deep pools for fish. Native trees and grasses, planted along the banks, will lower downstream flood risks and shade cooler water. More than a mile of levee will be removed or set back to reconnect 50 acres of floodplain, slowing the springtime surge and storing water in underground aquifers for healthier late summer flows.

Construction will take about three years and $5 million to finish. The Salmon Recovery Funding Board, Confederated Tribes of the Umatilla Indian Reservation (CTUIR), and Bonneville Power Administration are contributing about $3 million to the project, while our Floodplains by Design (FbD) program is providing $2.1 million. Ecology co-manages FbD with The Nature Conservancy and Puget Sound Partnership, helping Washington communities reduce local flood hazards while restoring aquatic habitat, improving water quality, and enhancing outdoor recreation.