Synthesizing Studies of Dam Removal

Abstract

Dam decommissioning is rapidly emerging as an important river restoration strategy in the United States. Hundreds of dams have been removed in the past few decades, including several large ones (>10–15 meters) impounding large sediment volumes (>10 6 cubic meters) in the past 3 years, notably Condit Dam and the Elwha River dams in Washington State. These removals and the associated studies provide for the first time an opportunity to evaluate the immediate and persistent consequences of these significant fluvial—and in some cases, coastal—perturbations. Understanding dam removal response not only improves understanding of landscape and ecosystem adjustment to profound sediment pulses but also provides important lessons for future watershed restoration efforts.