Just over one hundred years ago, a dam was constructed to provide power for local logging operations and residences, but cut off the upper section of the Elwha River in Washington.
Constructed between 1910 and 1913, the Elwha dam effectively cut off five species of salmon, as well as other trout species, from their spawning grounds. The Glines Canyon dam, completed between 1925 and 1927, only added to environmental stress on the Elwha River. Before 1913, some 400,000 salmon used to make the arduous journey to spawn in some 70 miles of river habitat, but the dam reduced available river habitat to just five miles. The number of salmon making the annual spawning run plummeted to just a few thousand individuals.
Starting in 2010, with the purchase of the dams by the federal government, plans were set in motion to restore the Elwha River and surrounding areas of Olympic National Park to their original and natural state (pdf-link). Dam removal, recovery operations, reservoir draining, and other works began the next year. So far, the Elwha dam has been removed, and only a third of the Glines Canyon dam remains, and Lake Mills and Lake Aldwell have been drained, restoring the Elwha River to its original channel.
Much of the restoration of the Elwha River has been accomplished by the river itself, flushing rich sediments and organic materials out to sea. Workers are planting hundreds of thousands of native seeds and seedlings to restore the landscape now exposed to the elements. Now that Elwha River flow has been restored along its entire length, salmon are exploring the river habitat along its entire length, and the first salmon fry have been already been seen in the waters above the site of the Elwha dam. As the salmon population is restored in the next few decades, it is expected that other native species will also return to the area, such as eagles and bears, which depend on the salmon spawning run as a rich food source.