The Issue: 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. Beginning in 2011, two large dams on the Elwha River in Clallam County, Washington, will be removed by the National Park Service over about two and a half years. During removal, sediment accumulated behind the dams over the last several decades is expected to mobilize, creating high suspended-sediment levels in the lower river and significant impacts on river, lake, and nearshore ecosystems.
How the USGS will help: The USGS, working in collaboration with the Lower Elwha Klallam Tribe, will monitor and interpret suspended-sediment load data and suspended-sediment transport along the lower Elwha River, the coastal estuary complex, and the nearshore where the Elwha River enters the Strait of Juan de Fuca. The USGS will also monitor the biological response of the nearshore benthic ecosystem to increased sedimentation.
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.
Below are publications associated with this project.
River turbidity and sediment loads during dam removal
Dam decommissioning has become an important means for removing unsafe or obsolete dams and for restoring natural fluvial processes, including discharge regimes, sediment transport, and ecosystem connectivity [Doyle et al., 2003]. The largest dam-removal project in history began in September 2011 on the Elwha River of Washington State (Figure 1a). The project, which aims to restore the river ecosys
Elwha River dam removal-Rebirth of a river
Coastal habitats of the Elwha River, Washington- Biological and physical patterns and processes prior to dam removal
Below are partners associated with this project.
The Issue: 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. Beginning in 2011, two large dams on the Elwha River in Clallam County, Washington, will be removed by the National Park Service over about two and a half years. During removal, sediment accumulated behind the dams over the last several decades is expected to mobilize, creating high suspended-sediment levels in the lower river and significant impacts on river, lake, and nearshore ecosystems.
How the USGS will help: The USGS, working in collaboration with the Lower Elwha Klallam Tribe, will monitor and interpret suspended-sediment load data and suspended-sediment transport along the lower Elwha River, the coastal estuary complex, and the nearshore where the Elwha River enters the Strait of Juan de Fuca. The USGS will also monitor the biological response of the nearshore benthic ecosystem to increased sedimentation.
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.
Below are publications associated with this project.
River turbidity and sediment loads during dam removal
Dam decommissioning has become an important means for removing unsafe or obsolete dams and for restoring natural fluvial processes, including discharge regimes, sediment transport, and ecosystem connectivity [Doyle et al., 2003]. The largest dam-removal project in history began in September 2011 on the Elwha River of Washington State (Figure 1a). The project, which aims to restore the river ecosys
Elwha River dam removal-Rebirth of a river
Coastal habitats of the Elwha River, Washington- Biological and physical patterns and processes prior to dam removal
Below are partners associated with this project.