For thousands of years, the
Duwamish people have lived along the Duwamish River and its tributaries. The earliest archaeological evidence of human habitation along the Duwamish River dates back to the 6th century CE. The Duwamish traditionally used the river to hunt ducks and geese, fish for salmon, cod, and halibut, harvest clams, and gather berries, camas, and other plants for food and medicinal purposes. When the first American settlers came to what is now the
Seattle area in 1851, the Duwamish lived in more than 90 longhouses, in at least 17 villages. Until 1906, the
White and
Green Rivers combined at
Auburn, and joined the
Black River at
Tukwila to form the Duwamish. In 1906, however, the White River changed course following a major flood and emptied into the
Puyallup River as it does today. The lower portion of the historic White River—from the historic confluence of the White and Green Rivers to the
confluence with the Black River—is now considered part of the Green River. Later, in 1911 the
Cedar River was diverted to empty into
Lake Washington instead of into the Black River; at that time, the lake itself still emptied into the Black River. 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. From that time forward, the point of the name change from Green to Duwamish is no longer the confluence of the Green and Black Rivers, though it has not changed location. The last year-round Duwamish residents on the river – an old man named Seetoowathl, and his wife – died of starvation in their float-house on Kellogg Island in the winter of 1920. In 2009, the Duwamish Longhouse and Cultural Center was opened on the west bank of the river as part of the Duwamish Tribal Organization's reassertion of its historic rights in the area and its continuing struggle for federal recognition as the Duwamish Tribe.
Duwamish Waterway As of the present day, the
Duwamish Waterway empties into
Elliott Bay in
Seattle. The waterway was completed after the completion of the man-made
Harbor Island in 1909. The waterway is now divided into two channels, the East and West Waterways. In 1895,
Eugene Semple, who had earlier served as Governor of
Washington Territory, outlined a plan for a series of major public works projects in the Seattle area, including the straightening and dredging of the Duwamish River, both to open up the area to commercial use and to alleviate flooding. In 1909 the City of Seattle formed the Duwamish Waterway Commission to sell bonds and oversee the re-channelling of the river. Work began in October 1913, and the oxbows gradually disappeared, with a few recesses in the channel left to accommodate high water flows and turning ships. Parts of the
Georgetown and
South Park neighborhoods once on quiet riverbank found themselves inland; the
Georgetown Steam Plant was now almost a mile from the river, and special water pumping facilities had to be installed. By 1920, 4½ miles of the Duwamish Waterway had been dredged to a depth of 50 feet, with 20 million cubic feet of mud and sand going into the expansion of Harbor Island. The shallow, meandering, nine-mile-long river became a five-mile engineered waterway capable of handling ocean-going vessels. The Duwamish basin soon became Seattle's industrial and commercial core area. Activities included cargo handling and storage, marine construction, ship and boat manufacturing, concrete manufacturing, paper and metals fabrication, food processing, and countless other industrial operations.
Boeing Plant 1 was established on the Lower Duwamish in 1916, and
Boeing Plant 2, further upriver, in 1936. The contaminants include
PCBs,
PAHs,
arsenic,
mercury, and
phthalates, discharged from multiple industries. The cleanup included a plan for an "early action" or hotspot cleanup proposed to dredge contaminated sediment and dump the resulting
sludge in
Tacoma's Commencement Bay, to the southwest. Opposition to this plan in both Seattle and Tacoma forced the sludge to be shipped to
Klickitat County in south central
Washington instead of disposal in Puget Sound. EPA has identified responsible parties for the pollution and in 2014 it published a final cleanup plan. By late 2015, 50 percent of the PCB-contaminated sediment had been removed. Other common contamination occurs from farms,
surface runoff, or failing septic tanks. With the spread of ecological concerns in the 1970s, various environmental, tribal, and community organizations became interested in the severely polluted Duwamish River and Waterway. Kellogg Island, the last remnant of the original river, was declared a wildlife preserve, and nearby terminal T-107 was converted into a park, creating a substantial natural area near the mouth of the river.{{cite web |title=$4.6 Million Project Will Restore 16.5 Acres of Critical Aquatic Habitat Along Lower Duwamish River at Seaboard Lumber Site |url=http://www.publicaffairs.noaa.gov/pr98/nov98/noaa98-r158.html |date=November 3, 1998 ==Wildlife==