Geomorphology, Sediment, and Habitat
Geomorphology, Sediment, and Habitat
Rivers shape the landscape as they deliver water and sediment from the mountains down to the floodplains and deltas. However, it is possible for the erosion and deposition of sediment by rivers to increase the risk of flooding and impact the health of river ecosystems. USGS geomorphology can provide decision makers with a better understanding of these hazards by evaluating historical trends, current conditions, and potential future impacts from changes in climate and land uses. Hydrologists and geomorphologists of the USGS Washington Water Science Center monitor and study river hydraulics; sediment sources and transport in rivers from the mountains to the ocean; the role of large wood, levees and other features in influencing river channel shape stability; and the relation between all these factors and river habitat and ecology as well as river flooding.
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Coastal Habitats in Puget Sound
A Pacific Northwest icon, Puget Sound is the second-largest estuary in the United States. Its unique geology, climate, and nutrient-rich waters produce and sustain biologically productive coastal habitats. These same natural characteristics also contribute to a high quality of life that has led to growth in human population and urbanization. This growth has played a role in degrading the Sound...
Channel change monitoring following the Pilchuck Dam removal
The issue: In the summer of 2020, the Pilchuck Dam will be removed, allowing salmon access to the upper third of the Pilchuck River watershed for the first time in over a century. This removal will be associated with a short period increased sediment delivery, as the river re-works material trapped behind the dam. While the volume of impounded sediment is small and major changes in the downstream...
Assessment of Sediment Quality and Volume behind Enloe Dam
The Issue: The Enloe Dam, a 100-yr old structure on the Similkameen River in Washington State, has not produced hydropower since 1958 and options are being considered for potential removal of the dam. The concentrations of sediment contaminants (primarily trace elements from a long history of mining and smelting operations in the US and Canada) trapped by Enloe Dam are unknown and may be high...
Quantifying suspended-sediment load and transport characteristics in the Calawah and Upper Bogachiel Rivers, Washington
The issue: Salmonid fisheries are an important cultural and economic activity and efforts to support a thriving fisheries industry remain a major priority for the Quileute Tribe on the Olympic Peninsula, Washington. Land use changes can have a profound influence on basin sediment production with direct effects on fisheries (Madej and Ozaki, 2009). Studies are needed to improve estimates of the...
Coarse sediment delivery and routing in the White River
The Issue: Ongoing channel aggradation has reduced flow conveyance along the lower White River, increasing the flood risk in urban-suburban areas. A refined understanding of the delivery, transport and deposition of sediment in the White River, and how those processes may be influenced by climate and existing dam operations, is necessary in order to plan for future flood hazard in the lower White...
Fine sediment infiltration in Chinook spawning gravels in the Sauk River Basin, Washington
The Issue: There is concern that inherently high finer-grained (small gravel, sand, and silt) sediment loads in the Sauk River system may adversely affect egg-to-fry survival of ESA-listed Chinook salmon in the Sauk River and lower Skagit River Basin. However, there are no quantitative data for the Sauk River basin to assess if fine sediment deposition and infiltration into spawning gravels are at...
Sediment Transport in Vance Creek
The Issue: Streamflow in the lower 3.6 miles of the gravel-bedded Vance Creek often goes subsurface in the summer, limiting potential utilization by fish. There is an interest in stream restoration projects that might improve low-flow habitat conditions and connectivity, but their design and implementation are limited by a lack of knowledge about sediment transport conditions in the reach. How...
Sumas River Sediment Load
The Issue: A large, clay-rich active landslide on the western flank of Sumas Mountain in Whatcom County, Washington, is a significant source of sediment to Swift Creek and the salmon-bearing Sumas River. The landslide contains naturally occurring serpentinite that weathers to chrysotile asbestos and elevated levels of metals. The asbestos load in water as well as deposits along the banks and flood...
Elwha River Sediment Monitoring
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...
Geomorphology & Sediment Transport
Geomorphology is the study of the formation and evolution of landforms on Earth's surface. In the Pacific Northwest, volcanoes, tectonic movement, glaciers, rain, snow, wind, vegetation, animals, and people all shape the landscape at different scales of time and space. Of particular interest in the region is the form and processes of rivers, a branch of the science termed fluvial geomorphology...
Quantifying Floodplain Ecological Processes and Ecosystem Services in the Delaware River Watershed
Floodplain and wetland areas provide critical ecosystem services to local and downstream communities by retaining sediments, nutrients, and floodwaters. The loss of floodplain functionality due to land use conversion and degradation reduces the provisioning of these services. Assessing, quantifying, and valuing floodplain ecosystem services provide a framework to estimate how floodplain systems...
Sauk River Sediment
Fine-grained sediments in the lower reach of the Sauk River are adversely affecting the health and spawning of Chinook salmon. Climate change and forestry practices have been proposed as suspected causes of a reported increase in sediment loading to the river. To determine the amount and timing of suspended-sediment loading to the river and possible connections to adverse effects on Chinook salmon...