Christopher P Konrad
Science and Products
USGS science supporting the Elwha River Restoration Project
The Elwha River Restoration Project...
... has reconnected the water, salmon, and sediment of a pristine river and coast of the Olympic Peninsula of Washington. Coordinated by the National Park Service, restoration of the Elwha River included the removal of two large dams that had blocked salmon and sediment passage for almost 100 years. The largest dam removal in U.S. history began in...
River Corridor hot spots for biogeochemical processing: a continental scale synthesis
Rivers are the veins of the landscape, providing environmental benefits that are disproportionately high relative to their aerial extent; shedding flood waters, hosting aquatic ecosystems, transporting solutes and energy-rich materials, and storing and transforming pollutants into less harmful forms. From uplands to the coasts, rivers facilitate key biogeochemical reactions that cumulatively...
GW/SW Interactions
Knowing the interactions of ground water and river water can help reduce the fluctuation of water supplies in alluvial (sediment-deposit) river basins.
To develop general principles of these interactions in order to identify and analyze them, the USGS is reviewing the results of the numerous studies of these interactions in Pacific Northwest basins. The review will describe common...
Effects of urban multi-stressors on three stream biotic assemblages
During 2014, the U.S. Geological Survey (USGS) National Water-Quality Assessment(NAWQA) project assessed stream quality in 75 streams across an urban disturbance gradient within the Piedmont ecoregion of southeastern United States. Our objectives were to identify primary instream stressors affecting algal, macroinvertebrate...
Waite, Ian R.; Munn, Mark D.; Moran, Patrick W.; Konrad, Christopher P.; Nowell, Lisa H.; Meador, Michael R.; Van Metre, Peter C.; Carlisle, Daren M. Factors influencing fine sediment on stream beds in the Midwestern United States
Fine sediment (particles <2 mm in diameter) in stream beds has wide-ranging effects on hydraulics, geomorphology, and ecology and is a primary focus for stream quality management in many regions. We identify reach- and basin-scale factors associated with fine sediment in the beds of 83 stream reaches in the Midwestern United States using...
Konrad, Christopher P.; Gellis, Allen Effect of river confinement on depth and spatial extent of bed disturbance affecting salmon redds
Human impacts on rivers threaten the natural function of riverine ecosystems. This paper assesses how channel confinement affects the scour depth and spatial extent of bed disturbance and discusses the implications of these results for salmon-redd disturbance in gravel-bedded rivers. Two-dimensional hydrodynamic models of relatively confined and...
Christiana R. Czuba; Czuba, Jonathan A. ; Magirl, Christopher S.; Gendaszek, Andrew S.; Konrad, Christopher P. Assessing the influence of multiple stressors on stream diatom metrics in the upper Midwest, USA
Water resource managers face increasing challenges in identifying what physical and chemical stressors are responsible for the alteration of biological conditions in streams. The objective of this study was to assess the comparative influence of multiple stressors on benthic diatoms at 98 sites that spanned a range of stressors in an...
Munn, Mark D.; Waite, Ian R.; Konrad, Christopher P. Characterizing aquatic habitats for long‐term monitoring of a fourth‐order, regulated river in the Pacific Northwest, USA
A pragmatic approach to the long‐term monitoring of rivers leverages available information with targeted field investigations to address key uncertainties relevant to management decisions. An over‐arching management issue for many rivers is how reservoir operation affects the amount and location of in‐channel sediment and the resulting...
Konrad, Christopher P.; Burton, K.; Little, R.; Gendaszek, Andrew S.; Munn, Mark D.; Anderson, Scott W. Streambed scour of salmon spawning habitat in a regulated river influenced by management of peak discharge
In the Pacific Northwest of the United States, salmon eggs incubating within streambed gravels are susceptible to scour during floods. The threat to egg-to-fry survival by streambed scour is mitigated, in part, by the adaptation of salmon to bury their eggs below the typical depth of scour. In regulated rivers globally, we suggest that water...
Gendaszek, Andrew S.; Burton, Karl D.; Magirl, Christopher S.; Konrad, Christopher P. Flood runoff in relation to water vapor transport by atmospheric rivers over the western United States, 1949–2015
Atmospheric rivers (ARs) have a significant role in generating floods across the western United States. We analyze daily streamflow for water years 1949 to 2015 from 5,477 gages in relation to water vapor transport by ARs using a 6 h chronology resolved to 2.5° latitude and longitude. The probability that an AR will generate 50 mm/d of...
Konrad, Christopher P.; Dettinger, Michael D. Hydrologic metrics for status-and-trends monitoring in urban and urbanizing watersheds
Local governmental agencies are increasingly undertaking potentially costly “status-and-trends” monitoring to evaluate the effectiveness of stormwater control measures and land-use planning strategies, or to satisfy regulatory requirements. Little guidance is presently available for such efforts, and so we have explored the application,...
Booth, Derek B.; Konrad, Christopher P. Classification of California streams using combined deductive and inductive approaches: Setting the foundation for analysis of hydrologic alteration
Regional classification of streams is an early step in the Ecological Limits of Hydrologic Alteration framework. Many stream classifications are based on an inductive approach using hydrologic data from minimally disturbed basins, but this approach may underrepresent streams from heavily disturbed basins or sparsely gaged arid regions. An...
Pyne, Matthew I.; Carlisle, Daren M.; Konrad, Christopher P.; Stein, Eric D. Integrating seasonal information on nutrients and benthic algal biomass into stream water quality monitoring
Benthic chlorophyll a (BChl a) and environmental factors that influence algal biomass were measured monthly from February through October in 22 streams from three agricultural regions of the United States. At-site maximum BChl a ranged from 14 to 406 mg/m2 and generally varied with dissolved inorganic nitrogen (DIN): 8 out of 9 sites with at-...
Konrad, Christopher P.; Munn, Mark D.
Magnitude, frequency, and trends of floods at gaged and ungaged sites in Washington, based on data through water year 2014
An investigation into the magnitude and frequency of floods in Washington State computed the annual exceedance probability (AEP) statistics for 648 U.S. Geological Survey unregulated streamgages in and near the borders of Washington using the recorded annual peak flows through water year 2014. This is an updated report from a previous report...
Mastin, Mark C.; Konrad, Christopher P.; Veilleux, Andrea G.; Tecca, Alison E.
Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington
Nutrients such as nitrogen and phosphorus are important for aquatic ecosystem health. Excessive amounts of nutrients, however, can make aquatic ecosystems harmful for biota because enhanced growth and decay cycles of aquatic algae can reduce dissolved oxygen in the water. In Puget Sound marine waters, low dissolved oxygen concentrations are...
Sheibley, Richard W.; Konrad, Christopher P.; Black, Robert W.