Channel Change and Sediment Transport in the Puyallup River Watershed
The Issue: Sediment loads in the Puyallup River and its major tributaries, the White River and Carbon River, are high and river channels are dynamic. While there is a relatively rich history of sediment transport and channel change studies in the Puyallup River and its tributaries, there has not been an integrated assessment of channel-elevation trends in nearly a decade. This lack of up-to-date information makes it difficult to incorporate channel-elevation change into current flood-hazard management plans. Limited information about the persistence of elevation trends and the sourcing and routing of sediment over decadal timescales makes it difficult to determine how elevations may change in coming decades.
How USGS will help: The USGS will assess topographic change of river channels throughout the Puyallup River watershed, leveraging existing repeat high-resolution topographic datasets. This work will be paired with analyses of other existing data, including elevation trends at USGS gages, change relative to 1907 surveys, and direct measurements of sediment transport to better understand recent channel elevation trends and their potential causes.
Problem: The Puyallup River watershed drains 948 mi2 in western Washington, originating in glaciated terrain on the flanks of Mount Rainier. Sediment loads in the Puyallup River and its major tributaries, the White River and Carbon River, are high and river channels are dynamic (Czuba et al., 2010, 2012). The dynamic and sediment-rich nature of these rivers complicate management and restoration activities.
While there is a relatively rich history of sediment transport and channel change studies in the Puyallup River and its tributaries (Dunne, 1986; Prych, 1988; Sikonia, 1990; Czuba et al., 2010, 2012), there has not been an integrated assessment of channel-elevation trends in nearly a decade. This lack of up-to-date information makes it difficult to incorporate channel-elevation change into current flood-hazard management plans. A lack of information about the persistence of elevation trends, along with the sourcing and routing of sediment over decadal timescales, also limits exploration of potential for trends moving forward.
Objectives: The objective of this work is to synthesize existing data regarding sediment transport and channel change in the Puyallup River watershed, leaning particularly on high-resolution topographic datasets collected in recent decades. This synthesis will provide an updated view of riverbed elevation trends and watershed sediment source and sinks. This synthesis will be used to inform existing management and restoration strategies and identify any key information gaps that may be addressed through monitoring efforts.
Relevance and Benefits: This work will help inform flood hazard and restoration management actions in the Puyallup River. This work will also contribute to the growing regional understanding of the delivery, transport, and fate of sediment in the dynamic landscape of western Washington (e.g. Collins et al, 2019; Anderson and Shean, 2021; Scott and Collins, 2021; Pfeiffer et al., 2022), with relevance to hazard analysis and ecosystem functioning across riverine, deltaic, and near-shore environments (Czuba et al., 2011).
Approach: This work involves multiple assessments of channel change and sediment-transport rates. These include assessments of repeat topographic surveys, and particularly newly-available high-resolution lidar and structure-from-motion surveys, inference of channel change based on USGS stream gage records, and sediment load estimation based on discrete sediment flux measurements. All analyses are based on existing data, using methods established and applied elsewhere in the region (Czuba et al., 2010; Anderson and Konrad, 2019). This work is modeled closely on previous analyses completed in the White River (Anderson and Jaeger, 2021) using the same methods and, in many cases, the same specific datasets.
The Issue: Sediment loads in the Puyallup River and its major tributaries, the White River and Carbon River, are high and river channels are dynamic. While there is a relatively rich history of sediment transport and channel change studies in the Puyallup River and its tributaries, there has not been an integrated assessment of channel-elevation trends in nearly a decade. This lack of up-to-date information makes it difficult to incorporate channel-elevation change into current flood-hazard management plans. Limited information about the persistence of elevation trends and the sourcing and routing of sediment over decadal timescales makes it difficult to determine how elevations may change in coming decades.
How USGS will help: The USGS will assess topographic change of river channels throughout the Puyallup River watershed, leveraging existing repeat high-resolution topographic datasets. This work will be paired with analyses of other existing data, including elevation trends at USGS gages, change relative to 1907 surveys, and direct measurements of sediment transport to better understand recent channel elevation trends and their potential causes.
Problem: The Puyallup River watershed drains 948 mi2 in western Washington, originating in glaciated terrain on the flanks of Mount Rainier. Sediment loads in the Puyallup River and its major tributaries, the White River and Carbon River, are high and river channels are dynamic (Czuba et al., 2010, 2012). The dynamic and sediment-rich nature of these rivers complicate management and restoration activities.
While there is a relatively rich history of sediment transport and channel change studies in the Puyallup River and its tributaries (Dunne, 1986; Prych, 1988; Sikonia, 1990; Czuba et al., 2010, 2012), there has not been an integrated assessment of channel-elevation trends in nearly a decade. This lack of up-to-date information makes it difficult to incorporate channel-elevation change into current flood-hazard management plans. A lack of information about the persistence of elevation trends, along with the sourcing and routing of sediment over decadal timescales, also limits exploration of potential for trends moving forward.
Objectives: The objective of this work is to synthesize existing data regarding sediment transport and channel change in the Puyallup River watershed, leaning particularly on high-resolution topographic datasets collected in recent decades. This synthesis will provide an updated view of riverbed elevation trends and watershed sediment source and sinks. This synthesis will be used to inform existing management and restoration strategies and identify any key information gaps that may be addressed through monitoring efforts.
Relevance and Benefits: This work will help inform flood hazard and restoration management actions in the Puyallup River. This work will also contribute to the growing regional understanding of the delivery, transport, and fate of sediment in the dynamic landscape of western Washington (e.g. Collins et al, 2019; Anderson and Shean, 2021; Scott and Collins, 2021; Pfeiffer et al., 2022), with relevance to hazard analysis and ecosystem functioning across riverine, deltaic, and near-shore environments (Czuba et al., 2011).
Approach: This work involves multiple assessments of channel change and sediment-transport rates. These include assessments of repeat topographic surveys, and particularly newly-available high-resolution lidar and structure-from-motion surveys, inference of channel change based on USGS stream gage records, and sediment load estimation based on discrete sediment flux measurements. All analyses are based on existing data, using methods established and applied elsewhere in the region (Czuba et al., 2010; Anderson and Konrad, 2019). This work is modeled closely on previous analyses completed in the White River (Anderson and Jaeger, 2021) using the same methods and, in many cases, the same specific datasets.