The Duwamish River is the name of the lower 12 miles (19 km) of Washington state's Green River. Its industrialized estuary is known as the Duwamish Waterway. At one time, the Black River and the White and Green Rivers, which combined at Auburn, joined at Tukwila to form the Duwamish; however, in 1912 the Cedar River was diverted to empty into Lake Washington instead of the Black River, though the lake itself still emptied into the Black. Then, with the opening of the Lake Washington Ship Canal in 1916, the lake's level dropped nearly nine feet and the Black River dried up. Hence the point of the name change is no longer the confluence of the Green and Black rivers, though it has not changed location.

The lower Duwamish River and the First Avenue South Bridge (Washington State Route 99)

The Duwamish Waterway empties into Elliott Bay in Seattle, divided by the man-made Harbor Island into two channels, the East and West Waterways.

Due to 20th century industrial contamination, the lower five miles (8 km) of the Duwamish was declared a Superfund site by the Environmental Protection Agency. The contaminants include PCBs, PAHs, mercury, and phthalates. [1] (http://yosemite.epa.gov/r10/cleanup.nsf/sites/lduwamish) The cleanup of the river has been controversial: the original plan was to dredge the river and dump the resulting sludge in Tacoma's Commencement Bay, 26 miles to the southwest. Local opposition to this plan forced the sludge to be shipped to Klickitat County in south central Washington.[2] (http://seattlepi.nwsource.com/local/139087_sludge11.html)

External link

• Aerial photo (http://www.ci.seattle.wa.us/business/dc/map/dcphoto.htm)