Landsat imagery acquired in 2011 and 2012 illustrate the changes to the Elwha River basin in the Washington State Olympic Peninsula after the removal of the Elwha River dam.
The Elwha and Glines Canyon dams were constructed in the 1920s to provide hydroelectric power to the region. Over subsequent decades the dams became less efficient, the machinery outdated, and the reservoirs heavily silted. Further, the dams prevented salmon from reaching upstream habitat.
In 1992, Congress authorized the removal of the dams. The Elwha dam was removed in early 2012, and the Glines Canyon dam is scheduled for removal by late 2013.
The Landsat images show the impact of dam removal. The reservoir behind the dam is gone, the exposed silt deposits are gradually being removed, and natural river flow, important to salmon habitat, is being restored.