Charles Stillwell, Ph.D.
Charlie Stillwell is a Hydrologist for the South Atlantic Water Science Center’s Watershed and Statistical Hydrology Team.
I study hydrology in altered watersheds, particularly those impacted by urbanization. How does development affect flow and water quality? Can green infrastructure counteract hydrologic alteration? I use statistical, data-driven methods to understand these patterns. My research supports water resource decision makers.
Professional Experience
Hydrologist, U.S. Geological Survey, South Atlantic Water Science Center, 2018-present
Education and Certifications
Ph.D. Biological & Agricultural Engineering, North Carolina State University, 2019
M.Eng. Biological & Agricultural Engineering, North Carolina State University, 2016
B.S. Civil Engineering, Drexel University, 2014
Science and Products
Predictive modeling reveals elevated conductivity relative to background levels in freshwater tributaries within the Chesapeake Bay watershed, USA
Elevated conductivity (i.e., specific conductance or SC) causes osmotic stress in freshwater aquatic organisms and may increase the toxicity of some contaminants. Indices of benthic macroinvertebrate integrity have declined in urban areas across the Chesapeake Bay watershed (CBW), and more information is needed about whether these declines may be due to elevated conductivity. A...
Authors
Rosemary M. Fanelli, Joel Moore, Charles C. Stillwell, Andrew J. Sekellick, Richard H Walker
Development of the North Carolina stormwater-treatment decision-support system by using the Stochastic Empirical Loading and Dilution Model (SELDM)
The Federal Highway Administration and State departments of transportation nationwide need an efficient method to assess potential adverse effects of highway stormwater runoff on receiving waters to optimize stormwater-treatment decisions. To this end, the U.S. Geological Survey, in cooperation with the Federal Highway Administration and the North Carolina Department of Transportation...
Authors
Gregory E. Granato, Charles C. Stillwell, J. N. Weaver, Andrew H. McDaniel, Brian S. Lipscomb, Susan C. Jones, Ryan M. Mullins
Predicting inundation dynamics and hydroperiods of small, isolated wetlands using a machine learning approach
The duration of inundation or saturation (i.e., hydroperiod) controls many wetland functions. In particular, it is a key determinant of whether a wetland will provide suitable breeding habitat for amphibians and other taxa that often have specific hydrologic requirements. Yet, scientists and land managers often are challenged by a lack of sufficient monitoring data to enable the...
Authors
Jeffrey W. Riley, Charles C. Stillwell
Closing the gap on wicked urban stream restoration problems: A framework to integrate science and community values
Restoring the health of urban streams has many of the characteristics of a wicked problem. Addressing a wicked problem requires managers, academics, practitioners, and community members to make negotiated tradeoffs and compromises to satisfy the values and perspectives of diverse stakeholders involved in setting restoration project goals and objectives. We conducted a gap analysis on 11...
Authors
Brian M. Murphy, Kathryn L Russell, Charles C. Stillwell, Robert J. Hawley, Mateo Scoggins, Kristina G. Hopkins, Matthew J. Burns, Kristine T. Taniguchi-Quan, Kate H Macneale, Robert P Smith
Lessons learned from 20 y of monitoring suburban development with distributed stormwater management in Clarksburg, Maryland, USA
Urban development is a well-known stressor for stream ecosystems, presenting a challenge to managers tasked with mitigating its effects. For the past 20 y, streamflow, water quality, geomorphology, and benthic communities were monitored in 5 watersheds in Montgomery County, Maryland, USA. This study presents a synthesis of multiple studies of monitoring efforts in the study area and new...
Authors
Kristina G. Hopkins, Sean Woznicki, Brianna Williams, Charles C. Stillwell, Eric Naibert, Marina Metes, Daniel K. Jones, Dianna M. Hogan, Natalie Hall, Rosemary M. Fanelli, Aditi Bhaskar
Predicting flood damage probability across the conterminous United States
Floods are the leading cause of natural disaster damages in the United States, with billions of dollars incurred every year in the form of government payouts, property damages, and agricultural losses. The Federal Emergency Management Agency oversees the delineation of floodplains to mitigate damages, but disparities exist between locations designated as high risk and where flood damages...
Authors
Elyssa Collins, Georgina Maria Sanchez Salas, Adam Terando, Charles C. Stillwell, Helena Mitasova, Antonia Sebastian, Ross K. Meentemeyer
Evaluation of two existing flood management structures in U.S. Army Garrison Fort Gordon, Georgia, 2020
Two existing flood management structures in U.S. Army Garrison Fort Gordon, Georgia, were evaluated for potential retrofitting to address water-quality impacts, pursuant of U.S. Army Garrison Fort Gordon’s storm water management program. Stormwater calculations were computed according to the Georgia Stormwater Management Manual, including drainage area delineations, design-storm runoff...
Authors
Charles C. Stillwell
Monitoring water-quality and geomorphology in the French Broad River during I-26 construction
The North Carolina Department of Transportation (NCDOT) has partnered with the U.S. Geological Survey (USGS) to assess the water-quality and geomorphologic impacts resulting from the I-26 construction projects in western North Carolina. Streamflow, precipitation, and water-quality monitoring data, coupled with periodic assessments of geomorphology, will support the NCDOT construction-site...
Raleigh Bank Erosion Project
The City of Raleigh partnered with the U.S. Geological Survey (USGS) to assist in assessing streambank erosion hotspots along the City of Raleigh’s stream network to support the City’s efforts of prioritizing future stream mitigation projects. Streambank erosion potential will be assessed using remotely sensed light detection and ranging (lidar) data, field assessments of streambank conditions...
North Carolina Sustainable Rivers Program
In 2002, The Nature Conservancy and the U.S. Army Corps of Engineers launched a collaborative effort to find more sustainable ways to manage river infrastructure to maximize benefits for people and nature. As of 2021, the Sustainable Rivers Program study area includes 40 rivers, 89 reservoirs, and 10,953 downstream river miles. The USGS South Atlantic Water Science Center and USGS Wetland and...
Ft. Gordon, Georgia, Stormwater Assessment
Fort Gordon is a U.S. Department of the Army facility located in east-central Georgia, approximately 10 miles west of Augusta, Georgia). The U.S. Geological Survey (USGS) South Atlantic Water Science Center is working cooperatively with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon to assess the quality of...
Understanding the Effects of Stormwater Management Practices on Water Quality and Flow
Urban development can have detrimental impacts on streams including altering hydrology, increasing nutrient, sediment, and pollutant loadings, and degrading biological integrity. Stormwater Best Management Practices (BMPs) can be used to mitigate the effects of urban development by retaining large volumes of stormwater runoff and treating runoff to remove pollutants. This project focuses on...
Water, Water Everywhere: Adapting Water Control Operations and Floodplain Conservation Planning to Global Change
Global change processes are producing shifts in temperature, precipitation, and seasonal streamflow regimes across North America. Much of the floodplain hydrology in the U.S. is managed through water control operations, often implemented on short time scales (e.g., weekly decisions), in response to short-term changes in precipitation. This operational model does not account for potential...
Stream stage, stream temperature, and climate metrics for 30 streams spanning land use and management gradients in the Delmarva Peninsula of Delaware, Maryland, and Virginia, 2022
This data release contains summary metrics describing stream stage, stream water temperature, and short-term climate conditions (daily precipitation and air temperature) for 30 streams spanning gradients of forest and row-crop land uses and agricultural best management practice implementation in the Delmarva Peninsula of Delaware, Maryland, and Virginia, USA. This setting is the second...
Predictions of specific conductance and departures from background specific conductance in the Chesapeake Bay watershed, 2001-2016
Freshwater salinization is an emerging water quality issue for non-tidal streams and rivers in the Chesapeake Bay watershed (CBW), USA region. A model was developed to predict specific conductance (SC; a proxy for salinity) conditions across the CBW and departures from background SC. Discrete observations of SC from 1999-2016 were acquired from a published SC data inventory and...
Topographic datasets compiled for the Lower Roanoke River corridor in 2003, 2014, and 2020, North Carolina
This data release contains topographic information compiled for the Lower Roanoke River corridor located in eastern North Carolina. The Lower Roanoke River corridor includes the mainstem of the Roanoke River from Roanoke Rapids, NC (below the Roanoke Rapids dam) to the mouth of the Roanoke River at its confluence with the Albemarle Sound, and the associated floodplains and wetland areas...
Drainage network for the Greater Raleigh Area, North Carolina, 2015-2022
As part of a collaborative study with the City of Raleigh, North Carolina, the U.S. Geological Survey developed a drainage network for the Greater Raleigh Area, North Carolina using the most recent available lidar data, representing the years 2015 and 2022. This dataset includes the delineated drainage network (drainage_network.zip) and rasters representing the breached and filled...
Stream stage, stream temperature, and climate metrics for 30 streams spanning land use and management gradients in the Shenandoah Valley region of West Virginia and Virginia, 2021
This data release contains summary metrics describing stream stage, stream water temperature, and short-term climate conditions (daily precipitation and air temperature) for 30 streams spanning gradients of forest and pasture land uses and agricultural best management practice implementation in the Shenandoah Valley region of Virginia and West Virginia, USA. This setting is the first of...
Lidar-derived rasters of point density, elevation, and geomorphological features for 2013, 2015, and 2022 for the Greater Raleigh Area, North Carolina
As part of a collaborative study with the City of Raleigh, North Carolina, the U.S. Geological Survey developed a suite of high-resolution lidar-derived raster datasets for the Greater Raleigh Area, North Carolina, using repeat lidar data from the years 2013, 2015, and 2022. These datasets include raster representations of digital elevation models (DEMs), DEM of difference, the ten most...
Datasets for Rapid Assessment of Streambank Erosion Potential for Selected Streams throughout the Greater Raleigh Area, North Carolina, 2022
As part of a collaborative study with the City of Raleigh, North Carolina, the U.S. Geological Survey is assessing streambank erosion potential in selected stream reaches throughout the Greater Raleigh metropolitan area. Rapid field measurement techniques were used to assess streambank stability at 124 stream segments between January and March 2022. Field data were collected using the...
Data and Code for Predicting Flood Damage Probability Across the Conterminous United States
This data release contains the associated data described in the related primary publication, "Predicting Flood Damage Probability Across the Conterminous United States" (Collins et al. [2022], see Related External Resources section). Publicly available geospatial datasets and random forest algorithms were used to analyze the spatial distribution and underlying drivers of flood damage...
Application of the North Carolina Stochastic Empirical Loading and Dilution Model (SELDM) to Assess Potential Impacts of Highway Runoff
In 2013, the U.S. Geological Survey (USGS) in partnership with the U.S. Federal Highway Administration (FHWA) published a new national stormwater quality model called the Stochastic Empirical Loading Dilution Model (SELDM; Granato, 2013). The model is optimized for roadway projects but in theory can be applied to a broad range of development types. SELDM is a statistically-based...
Science and Products
Predictive modeling reveals elevated conductivity relative to background levels in freshwater tributaries within the Chesapeake Bay watershed, USA
Elevated conductivity (i.e., specific conductance or SC) causes osmotic stress in freshwater aquatic organisms and may increase the toxicity of some contaminants. Indices of benthic macroinvertebrate integrity have declined in urban areas across the Chesapeake Bay watershed (CBW), and more information is needed about whether these declines may be due to elevated conductivity. A...
Authors
Rosemary M. Fanelli, Joel Moore, Charles C. Stillwell, Andrew J. Sekellick, Richard H Walker
Development of the North Carolina stormwater-treatment decision-support system by using the Stochastic Empirical Loading and Dilution Model (SELDM)
The Federal Highway Administration and State departments of transportation nationwide need an efficient method to assess potential adverse effects of highway stormwater runoff on receiving waters to optimize stormwater-treatment decisions. To this end, the U.S. Geological Survey, in cooperation with the Federal Highway Administration and the North Carolina Department of Transportation...
Authors
Gregory E. Granato, Charles C. Stillwell, J. N. Weaver, Andrew H. McDaniel, Brian S. Lipscomb, Susan C. Jones, Ryan M. Mullins
Predicting inundation dynamics and hydroperiods of small, isolated wetlands using a machine learning approach
The duration of inundation or saturation (i.e., hydroperiod) controls many wetland functions. In particular, it is a key determinant of whether a wetland will provide suitable breeding habitat for amphibians and other taxa that often have specific hydrologic requirements. Yet, scientists and land managers often are challenged by a lack of sufficient monitoring data to enable the...
Authors
Jeffrey W. Riley, Charles C. Stillwell
Closing the gap on wicked urban stream restoration problems: A framework to integrate science and community values
Restoring the health of urban streams has many of the characteristics of a wicked problem. Addressing a wicked problem requires managers, academics, practitioners, and community members to make negotiated tradeoffs and compromises to satisfy the values and perspectives of diverse stakeholders involved in setting restoration project goals and objectives. We conducted a gap analysis on 11...
Authors
Brian M. Murphy, Kathryn L Russell, Charles C. Stillwell, Robert J. Hawley, Mateo Scoggins, Kristina G. Hopkins, Matthew J. Burns, Kristine T. Taniguchi-Quan, Kate H Macneale, Robert P Smith
Lessons learned from 20 y of monitoring suburban development with distributed stormwater management in Clarksburg, Maryland, USA
Urban development is a well-known stressor for stream ecosystems, presenting a challenge to managers tasked with mitigating its effects. For the past 20 y, streamflow, water quality, geomorphology, and benthic communities were monitored in 5 watersheds in Montgomery County, Maryland, USA. This study presents a synthesis of multiple studies of monitoring efforts in the study area and new...
Authors
Kristina G. Hopkins, Sean Woznicki, Brianna Williams, Charles C. Stillwell, Eric Naibert, Marina Metes, Daniel K. Jones, Dianna M. Hogan, Natalie Hall, Rosemary M. Fanelli, Aditi Bhaskar
Predicting flood damage probability across the conterminous United States
Floods are the leading cause of natural disaster damages in the United States, with billions of dollars incurred every year in the form of government payouts, property damages, and agricultural losses. The Federal Emergency Management Agency oversees the delineation of floodplains to mitigate damages, but disparities exist between locations designated as high risk and where flood damages...
Authors
Elyssa Collins, Georgina Maria Sanchez Salas, Adam Terando, Charles C. Stillwell, Helena Mitasova, Antonia Sebastian, Ross K. Meentemeyer
Evaluation of two existing flood management structures in U.S. Army Garrison Fort Gordon, Georgia, 2020
Two existing flood management structures in U.S. Army Garrison Fort Gordon, Georgia, were evaluated for potential retrofitting to address water-quality impacts, pursuant of U.S. Army Garrison Fort Gordon’s storm water management program. Stormwater calculations were computed according to the Georgia Stormwater Management Manual, including drainage area delineations, design-storm runoff...
Authors
Charles C. Stillwell
Monitoring water-quality and geomorphology in the French Broad River during I-26 construction
The North Carolina Department of Transportation (NCDOT) has partnered with the U.S. Geological Survey (USGS) to assess the water-quality and geomorphologic impacts resulting from the I-26 construction projects in western North Carolina. Streamflow, precipitation, and water-quality monitoring data, coupled with periodic assessments of geomorphology, will support the NCDOT construction-site...
Raleigh Bank Erosion Project
The City of Raleigh partnered with the U.S. Geological Survey (USGS) to assist in assessing streambank erosion hotspots along the City of Raleigh’s stream network to support the City’s efforts of prioritizing future stream mitigation projects. Streambank erosion potential will be assessed using remotely sensed light detection and ranging (lidar) data, field assessments of streambank conditions...
North Carolina Sustainable Rivers Program
In 2002, The Nature Conservancy and the U.S. Army Corps of Engineers launched a collaborative effort to find more sustainable ways to manage river infrastructure to maximize benefits for people and nature. As of 2021, the Sustainable Rivers Program study area includes 40 rivers, 89 reservoirs, and 10,953 downstream river miles. The USGS South Atlantic Water Science Center and USGS Wetland and...
Ft. Gordon, Georgia, Stormwater Assessment
Fort Gordon is a U.S. Department of the Army facility located in east-central Georgia, approximately 10 miles west of Augusta, Georgia). The U.S. Geological Survey (USGS) South Atlantic Water Science Center is working cooperatively with the U.S. Department of the Army Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon to assess the quality of...
Understanding the Effects of Stormwater Management Practices on Water Quality and Flow
Urban development can have detrimental impacts on streams including altering hydrology, increasing nutrient, sediment, and pollutant loadings, and degrading biological integrity. Stormwater Best Management Practices (BMPs) can be used to mitigate the effects of urban development by retaining large volumes of stormwater runoff and treating runoff to remove pollutants. This project focuses on...
Water, Water Everywhere: Adapting Water Control Operations and Floodplain Conservation Planning to Global Change
Global change processes are producing shifts in temperature, precipitation, and seasonal streamflow regimes across North America. Much of the floodplain hydrology in the U.S. is managed through water control operations, often implemented on short time scales (e.g., weekly decisions), in response to short-term changes in precipitation. This operational model does not account for potential...
Stream stage, stream temperature, and climate metrics for 30 streams spanning land use and management gradients in the Delmarva Peninsula of Delaware, Maryland, and Virginia, 2022
This data release contains summary metrics describing stream stage, stream water temperature, and short-term climate conditions (daily precipitation and air temperature) for 30 streams spanning gradients of forest and row-crop land uses and agricultural best management practice implementation in the Delmarva Peninsula of Delaware, Maryland, and Virginia, USA. This setting is the second...
Predictions of specific conductance and departures from background specific conductance in the Chesapeake Bay watershed, 2001-2016
Freshwater salinization is an emerging water quality issue for non-tidal streams and rivers in the Chesapeake Bay watershed (CBW), USA region. A model was developed to predict specific conductance (SC; a proxy for salinity) conditions across the CBW and departures from background SC. Discrete observations of SC from 1999-2016 were acquired from a published SC data inventory and...
Topographic datasets compiled for the Lower Roanoke River corridor in 2003, 2014, and 2020, North Carolina
This data release contains topographic information compiled for the Lower Roanoke River corridor located in eastern North Carolina. The Lower Roanoke River corridor includes the mainstem of the Roanoke River from Roanoke Rapids, NC (below the Roanoke Rapids dam) to the mouth of the Roanoke River at its confluence with the Albemarle Sound, and the associated floodplains and wetland areas...
Drainage network for the Greater Raleigh Area, North Carolina, 2015-2022
As part of a collaborative study with the City of Raleigh, North Carolina, the U.S. Geological Survey developed a drainage network for the Greater Raleigh Area, North Carolina using the most recent available lidar data, representing the years 2015 and 2022. This dataset includes the delineated drainage network (drainage_network.zip) and rasters representing the breached and filled...
Stream stage, stream temperature, and climate metrics for 30 streams spanning land use and management gradients in the Shenandoah Valley region of West Virginia and Virginia, 2021
This data release contains summary metrics describing stream stage, stream water temperature, and short-term climate conditions (daily precipitation and air temperature) for 30 streams spanning gradients of forest and pasture land uses and agricultural best management practice implementation in the Shenandoah Valley region of Virginia and West Virginia, USA. This setting is the first of...
Lidar-derived rasters of point density, elevation, and geomorphological features for 2013, 2015, and 2022 for the Greater Raleigh Area, North Carolina
As part of a collaborative study with the City of Raleigh, North Carolina, the U.S. Geological Survey developed a suite of high-resolution lidar-derived raster datasets for the Greater Raleigh Area, North Carolina, using repeat lidar data from the years 2013, 2015, and 2022. These datasets include raster representations of digital elevation models (DEMs), DEM of difference, the ten most...
Datasets for Rapid Assessment of Streambank Erosion Potential for Selected Streams throughout the Greater Raleigh Area, North Carolina, 2022
As part of a collaborative study with the City of Raleigh, North Carolina, the U.S. Geological Survey is assessing streambank erosion potential in selected stream reaches throughout the Greater Raleigh metropolitan area. Rapid field measurement techniques were used to assess streambank stability at 124 stream segments between January and March 2022. Field data were collected using the...
Data and Code for Predicting Flood Damage Probability Across the Conterminous United States
This data release contains the associated data described in the related primary publication, "Predicting Flood Damage Probability Across the Conterminous United States" (Collins et al. [2022], see Related External Resources section). Publicly available geospatial datasets and random forest algorithms were used to analyze the spatial distribution and underlying drivers of flood damage...
Application of the North Carolina Stochastic Empirical Loading and Dilution Model (SELDM) to Assess Potential Impacts of Highway Runoff
In 2013, the U.S. Geological Survey (USGS) in partnership with the U.S. Federal Highway Administration (FHWA) published a new national stormwater quality model called the Stochastic Empirical Loading Dilution Model (SELDM; Granato, 2013). The model is optimized for roadway projects but in theory can be applied to a broad range of development types. SELDM is a statistically-based...