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...
Cedar River Peak Flow Management
The Cedar River watershed provides two-thirds of the water supply for the greater Seattle metropolitan region, in addition to being home to numerous federally listed salmon species. The City of Seattle, through Seattle Public Utilities (SPU), works closely with the Cedar River Instream Flow Commission (IFC) to adaptively manage flows on the Cedar River. Seattle operates its water management...
Green River Geomorphic Responses
In the Pacific Northwest, water, sediment, and vegetation primarily determine the form of large river channels and shape their ecosystems. Dams on rivers affect all of these elements, with consequences for habitats and aquatic species. Understanding how water, sediment, and vegetation interact in habitats is key to managing rivers. In the case of the middle Green River in King County,...
Elwha River
The formerly free-flowing Elwha River was famous for the diversity and size of its salmon runs. After the construction of the Elwha Dam (1912) and the Glines Canyon Dam (1927), fish lost access to more than 70 miles of mainstem river and tributary habitat. As a result, all 10 runs of native Elwha salmon and sea-going trout declined sharply. Restoration of the Elwha River ecosystem will be...
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...
Methow River Basin
The Methow River Basin, located in North Central Washington in Okanogan County, is well known for its natural beauty, wildlife, outdoor recreation, and rural lifestyle. The Methow River and its tributaries are home to upper Columbia summer steelhead and spring Chinook salmon, which are both listed as endangered under the Endangered Species Act (ESA), and bull trout, which is listed as...
Hydrologic Urban Indicators
Storm water, the rainfall that runs off urban surfaces such as rooftops, pavement, and lawns, can affect streams in a number of ways. As urban development increases, storm water can run quickly into streams, increasing the volume and peak flows and reducing summer flows. Sediment and other contaminants can also be carried into the streams.
The Washington Department of Ecology (WDOE),...
Inclusion of pesticide transformation products is key to estimating pesticide exposures and effects in small U.S. streams
Improved analytical methods can quantify hundreds of pesticide transformation products (TPs), but understanding of TP occurrence and potential toxicity in aquatic ecosystems remains limited. We quantified 108 parent pesticides and 116 TPs in more than 3 700 samples from 442 small streams in mostly urban basins across five major regions of the...
Mahler, Barbara; Nowell, Lisa H.; Sandstrom, Mark W.; Bradley, Paul; Romanok, Kristin; Konrad, Christopher; Van Metre, Peter Accounting for temporal variability of streamflow in estimates of travel time
Retention, processing, and transport of solutes and particulates in stream corridors are influenced by the travel time of streamflow through stream channels, which varies dynamically with discharge. The effects of streamflow variability across sites and over time cannot be addressed by time-averaged models if parameters are based solely on the...
Konrad, Christopher P.; Schmadel, Noah; Harvey, Judson; Schwarz, Gregory E.; Gomez-Velez, Jesus; Boyer, Elizabeth W.; Scott, Durelle Low threshold for nitrogen concentration saturation in headwaters increases regional and coastal delivery
River corridors store, convey, and process nutrients from terrestrial and upstream sources, regulating delivery from headwaters to estuaries. A consequence of chronic excess nitrogen loading, as supported by theory and field studies in specific areas, is saturation of the biogeochemically-mediated nitrogen removal processes that weakens the...
Schmadel, Noah; Harvey, Judson; Alexander, Richard; Boyer, Elizabeth W.; Schwarz, Gregory E.; Gomez-Velez, Jesus D.; Scott, Durelle; Konrad, Christopher
Spectral analysis to quantify the response of groundwater levels to precipitation—Northwestern United States
Persistent atmospheric patterns that lead to wet and dry seasons and droughts over periods of months to decades and longer-term climate change over periods of decades to millennia affect groundwater resources. Changes in groundwater storage and the resulting groundwater discharge from most aquifers is relatively slow and steady compared to the...
Long, Andrew J.; Konrad, Christopher P.
Flow modification in the Nation’s streams and rivers
This report summarizes a national assessment of flowing waters conducted by the U.S. Geological Survey’s (USGS) National Water-Quality Assessment (NAWQA) Project and addresses several pressing questions about the modification of natural flows in streams and rivers. The assessment is based on the integration, modeling, and synthesis of...
Carlisle, Daren; Wolock, David M.; Konrad, Christopher P.; McCabe, Gregory J.; Eng, Ken; Theodore E. Grantham; Mahler, Barbara A conceptual framework for the identification and characterization of lacustrine spawning habitats for native lake charr Salvelinus namaycush
Lake charr Salvelinus namaycush are endemic to the formerly glaciated regions of North America and spawn primarily in lakes, unlike most other Salmoninae. Spawning habitats for lake charr are thought to be characterized by relatively large substrate particle sizes which provide sufficient interstitial spaces for egg incubation, but...
Riley, Stephen; Marsden, J. E.; Ridgway, M. S.; Konrad, Christopher; Farha, Steve A.; Thomas R. Binder; Trevor A. Middel; Esselman, Peter; Krueger, Charles C. Benthic algal (Periphyton) growth rates in response to nitrogen and phosphorus: Parameter estimation for water quality models
Nitrogen (N) and phosphorus (P) are important pollutants that can stimulate nuisance blooms of algae. Water-quality models (e.g., WASP, CE-QUAL-R1, CE-QUAL-ICM, QUAL2k) are valuable and widely used management tools for algal accrual because of excess nutrients in the presence of other limiting factors. These models utilize the Monod and Droop...
Schmidt, Travis S.; Konrad, Christopher; Miller, Janet L.; Whitlock, Stephen D.; Stricker, Craig A. Estimating minimum streamflow from measurements at ungauged sites in regions with streamflow‐gauging networks
Estimation of low flows in rivers continues to be a vexing problem despite advances in statistical and process‐based hydrological models. We develop a method to estimate minimum streamflow at seasonal to annual timescales from measured streamflow based on regional similarity in the deviations of daily streamflow from minimum streamflow for a...
Konrad, Christopher P. Seasonal precipitation influences streamflow vulnerability to the 2015 drought in the western United States
Streamflow was exceptionally low in the spring and summer of 2015 across much of the western United States because of a regional drought that exploited the sensitivity of both snow- and rain-dominant rivers. Streamflow during 2015 was examined at 324 gauges in the region to assess its response to the amount, form, and seasonal timing of...
Konrad, Christopher An integrated framework for ecological drought across riverscapes of North America
Climate change is increasing the severity and extent of extreme droughts events, posing a critical threat to freshwater ecosystems, particularly with increasing human demands for diminishing water supplies. Despite the importance of drought as a significant driver of ecological and evolutionary dynamics, current understanding of drought...
Kovach, Ryan; Dunham, Jason B.; Al-Chokhachy, Robert; Snyder, Craig; Beever, Erik A.; Pederson, Gregory T.; Lynch, Abigail; Hitt, Nathaniel P.; Konrad, Christopher P.; Jaeger, Kristin; Rea, Alan H.; Sepulveda, Adam J.; Lambert, Patrick M.; Stoker, Jason M.; Giersch, J. Joseph; Muhlfeld, Clint C.
Sediment storage and transport in the Nooksack River basin, northwestern Washington, 2006–15
The Nooksack River is a dynamic gravel-bedded river in northwestern Washington, draining off Mount Baker and the North Cascades into Puget Sound. Working in cooperation with the Whatcom County Flood Control Zone District, the U.S. Geological Survey studied topographic, hydrologic, and climatic data for the Nooksack River basin to document recent...
Anderson, Scott W.; Konrad, Christopher P.; Grossman, Eric E.; Curran, Christopher A. Downstream‐propagating channel responses to decadal‐scale climate variability in a glaciated river basin
Regional climate is an important control on the rate of coarse sediment mobilization and transport in alpine river systems. Changes in climate are then expected to cause a cascade of geomorphic responses, including adjustments in downstream channel morphology. However, the mechanics and sensitivity of channel response to short‐term climate...
Anderson, Scott W.; Konrad, Christopher P.
Low 2015 Snowpack and River Flows Studied to Provide Insight Into Future Droughts
U.S. Geological Survey hydrologic technicians are currently taking measurements from hundreds of streams and rivers across the western United States as part of a low flow study.