Coastal change from a massive sediment input: Dam removal, Elwha River, Washington, USA
The removal of two large dams on the Elwha River, Washington, provides an ideal opportunity to study coastal morphodynamics during increased sediment supply. The dam removal project exposed ~21 million cubic meters (~30 million tonnes) of sediment in the former reservoirs, and this sediment was allowed to erode by natural river processes. Elevated rates of sand and gravel sediment transport in the river occurred during dam removal. Most of the sediment was transported to the coast, and this renewed sediment supply resulted in hundreds of meters of seaward expansion of the river delta since 2011. Our most recent survey in January 2015 revealed that a cumulative ~3.5 million m3 of sediment deposition occurred at the delta since the beginning of the dam removal project, and that aggradation had exceeded 8 m near the river mouth. Some of the newly deposited sediment has been shaped by waves and currents into a series of subaerial berms that appear to move shoreward with time.
Citation Information
Publication Year | 2015 |
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Title | Coastal change from a massive sediment input: Dam removal, Elwha River, Washington, USA |
DOI | 10.1142/9789814689977_0161 |
Authors | Jonathan A. Warrick, Guy R. Gelfenbaum, Andrew W. Stevens, Ian M. Miller, George M. Kaminsky, Melissa M. Foley |
Publication Type | Conference Paper |
Publication Subtype | Conference Paper |
Index ID | 70157187 |
Record Source | USGS Publications Warehouse |
USGS Organization | Pacific Coastal and Marine Science Center |
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Jonathan Warrick
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Guy Gelfenbaum
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Jonathan Warrick
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Oceanographer EmeritusEmailPhone