USGS Washington Water Science Center
|Project Home | Maps | Data | Project Summaries | Publications and Products | Partnerships | Web Cams ||
WA11B - Elwha River Restoration Project: the Dynamics and Downstream Impacts of Fine Sediments Released After Dam Removal
Problem - The Elwha River Restoration Project is the largest single restoration action planned for the Puget Sound region in the foreseeable future and is a high priority for the Puget Sound Partnership. The removal of two large dams is expected to begin in 2011 and take approximately 2.5 years. A substantial fraction of the over 15 million m3 of sediment accumulated behind the dams, the majority of which is fine grained, is expected to erode, creating high-suspended-sediment levels in the lower river and significant impacts on fluvial, estuarine, and nearshore ecosystems.
Objectives - This study will provide the data and information to assist the Puget Sound Partnership, including state, federal, and tribal agencies to monitor key ecosystem indicators before, during, and after large-scale restoration. This study will provide key data to adaptively manage the Elwha River Restoration Project, and it will provide a better understanding of the impacts of large-scale dam removal on downstream ecosystems.
Relevance and Benefits - The study will monitor ecosystem impacts and responses to dam removal on a large salmon-bearing river in the Pacific Northwest. The study is consistent with the USGS strategic science direction "Understanding Ecosystems and Predicting Ecosystem Change: Ensuring the Nation's Economic and Environmental Future" identified in the 2007-17 science strategy of the USGS
Approach - The project is intended to occur for 3 years - 2010 through 2013 - which will encompass the entire dam-removal period. The focus will be on measuring sediment release, transport, and distribution in the lower Elwha River (below each dam), the estuary complex near the river mouth, and into the Strait of Juan de Fuca. The project has multiple components, related to water quality, sediment transport, sediment release and redistribution, and effects on biological communities in the nearshore.