Elwha River Still Changing Five Years After World’s Largest Dam-Removal Project: More than 20 million tons of sediment flushed to the sea
Starting in 2011, the National Park Service removed two obsolete dams from the Elwha River in Olympic National Park, Washington. It was the world’s largest dam-removal project. Over the next five years, water carrying newly freed rocks, sand, silt and old tree trunks reshaped more than 13 miles of river and built a larger delta into the Pacific Ocean.