Duwamish Waterway Programs

Healthier today than it has been since the early 1900s, the Duwamish Waterway was neglected for decades. Thanks in part to work spearheaded by the King County Wastewater Treatment Division and its predecessor, the Municipality of Metropolitan Seattle (Metro), the Duwamish Waterway is running toward a brighter future.

Draft Lower Duwamish Feasibility Study (FS). The Lower Duwamish Waterway cleanup process has reached a significant milestone with issuance of the draft Feasibility Study (FS). This document outlines and evaluates alternative methods for cleaning up contaminated sediments in a 5-mile portion of the Lower Duwamish Waterway.

View the Draft FS (issued April 24, 2009) and comments received (August 10, 2009), external link.
 View a 3-minute video (Windows Media Player) about the FS at the Duwamish River Festival.
(Video by King County staff.)

The Duwamish was once a meandering river supporting rich agricultural land and a fertile delta. Since then, the Duwamish has been straightened, channeled, dredged, filled, transformed (external link), and used for urban and industrial waste disposal.

King County continues to improve water quality in the Lower Duwamish Waterway through actions such as reducing combined sewer overflows (CSOs), restoring habitats, sediment capping and cleanup, and controlling toxicants from industries and stormwater runoff.

King County also partners with other public and private agencies and organizations to tackle these environmental concerns in the Duwamish. One such partnership, the Lower Duwamish Waterway Group (external link), formed in 2000 to bring together King County, City of Seattle, Port of Seattle and Boeing Co.