Scientific Investigations Report 2011–5120
This report includes chapters that summarize the results of multidisciplinary studies to quantify and characterize the current (2011) status and baseline conditions of the lower Elwha River, its estuary, and the adjacent nearshore ecosystems prior to the historic removal of two long-standing dams that have strongly influenced river, estuary, and nearshore conditions. The studies were conducted as part of the U.S. Geological Survey Multi-disciplinary Coastal Habitats in Puget Sound (MD-CHIPS) project. Chapter 1 is the introductory chapter that provides background and a historical context for the Elwha River dam removal and ecosystem restoration project. In chapter 2, the volume and timing of sediment delivery to the estuary and nearshore are discussed, providing an overview of the sediment stored in the two reservoirs and the expected erosion mechanics of the reservoir sediment deposits after removal of the dams. Chapter 3 describes the geological background of the Olympic Peninsula and the geomorphology of the Elwha River and nearshore. Chapter 4 details a series of hydrological data collected by the MD-CHIPS Elwha project. These include groundwater monitoring, surface water-groundwater interactions in the estuary, an estimated surface-water budget to the estuary, and a series of temperature and salinity measurements. Chapter 5 details the work that has been completed in the nearshore, including the measurement of waves, tides, and currents; the development of a numerical hydrodynamic model; and a description of the freshwater plume entering the Strait of Juan de Fuca. Chapter 6 includes a characterization of the nearshore benthic substrate developed using sonar, which formed a habitat template used to design scuba surveys of the benthic biological communities. Chapter 7 describes the ecological studies conducted in the lower river and estuary and includes characterization of juvenile salmon diets and seasonal estuary utilization patterns using otolith analysis to determine habitat specific and hatchery compared with wild patterns in juvenile Chinook salmon, assessment of benthic and terrestrial macroinvertebrate communities, and seasonal patterns of water nutrients. In Chapter 8, the vegetation communities of the eastern estuary are characterized by mapped vegetation cover types and samples collected for vegetation composition and diversity. Chapter 9 summarizes the existing conditions of the study area as detailed in this report and describes some of the possible outcomes of river restoration on the coastal ecosystems of the Elwha River.
Together, these different scientific perspectives form a basis for understanding the Elwha River ecosystem, an environment that has and will undergo substantial change. A century of change began with the start of dam construction in 1910; additional major change will result from dam removal scheduled to begin in September 2011. This report provides a scientific snapshot of the lower Elwha River, its estuary, and adjacent nearshore ecosystems prior to dam removal that can be used to evaluate the responses and dynamics of various system components following dam removal.
First posted September 7, 2011
For additional information contact:
Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.
Duda, J.J., Warrick, J.A., and Magirl, C.S., eds., 2011, Coastal habitats of the Elwha River, Washington— Biological and physical patterns and processes prior to dam removal: U.S. Geological Survey Scientific Investigations Report 2011–5120, 264 p.
Chapter 1.—Coastal and Lower Elwha River, Washington, Prior to Dam Removal— History, Status, and Defining Characteristics. By Jeffrey J. Duda, Jonathan A. Warrick, and Christopher S. Magirl
Chapter 2.—Anticipated Sediment Delivery to the Lower Elwha River During and Following Dam Removal. By Christiana R. Czuba, Timothy J. Randle, Jennifer A. Bountry, Christopher S. Magirl, Jonathan A. Czuba, Christopher A. Curran, and Christopher P. Konrad
Chapter 3.—Geomorphology of the Elwha River and its Delta. By Jonathan A. Warrick, Amy E. Draut, Michael L. McHenry, Ian M. Miller, Christopher S. Magirl, Matthew M. Beirne, Andrew W. Stevens, and Joshua B. Logan
Chapter 4.—Baseline Hydrologic Studies in the Lower Elwha River Prior to Dam Removal. By Christopher S. Magirl, Christopher A. Curran, Rich W. Sheibley, Jonathan A. Warrick, Jonathan A. Czuba, Christiana R. Czuba, Andrew S. Gendaszek, Patrick B. Shafroth, Jeffrey J. Duda, and James R. Foreman
Chapter 5.—Coastal Processes of the Elwha River Delta. By Jonathan A. Warrick, Andrew W. Stevens, Ian M. Miller, and Guy Gelfenbaum
Chapter 6.—Nearshore Biological Communities Prior to Removal of the Elwha River Dams. By Stephen P. Rubin, Ian M. Miller, Nancy Elder, Reginald R. Reisenbichler, and Jeffrey J. Duda
Chapter 7.—Aquatic Ecology of the Elwha River Estuary Prior to Dam Removal. By Jeffrey J. Duda, Matthew M. Beirne, Kimberly Larsen, Dwight Barry, Karl Stenberg, and Michael L. McHenry
Chapter 8.—Vegetation of the Elwha River Estuary. By Patrick B. Shafroth, Tracy L. Fuentes, Cynthia Pritekel, Matthew M. Beirne, and Vanessa B. Beauchamp
Chapter 9.—Summary and Anticipated Responses to Elwha River Dam Removal. By Guy Gelfenbaum, Jeffrey J. Duda, and Jonathan A. Warrick.