The Dan River Watershed
Overview of the river, its tributaries, and surrounding land
Map of Watershed
Delineation of Dan River watershed created via ArcGIS Pro showing watershed boundary and stream order. The Dan River originates near the Blue Ridge mountains of Patrick County and flows east towards Kerr Reservoir. Covers area in both Virginia and North Carolina. Major tributaries include Mayo, Smith, Sandy, and Hyco Rivers.
Watershed delineation completed by author using ArcGIS Pro
Characteristics
Please click through the slideshow for an overview of the watershed's features and characteristics.
Organizations
Threats and Challenges
Invasive Plants and Animals
Dendrology
Floodplains and Alluvial Soils
To assess soil types of the river's and its tributaries' floodplain, four sample sites were selected from the USDA's soil survey website. The sample sites vary in topography and land use classification in order to see how soil composition changes throughout the water shed.
Note: Only the top five most predominant soil types in each sample site are discussed below.
History of Flood and Drought
Red icons symbolize location of river gauges
The NOAA National Water Service and National Integrated Drought Information System uses river gauges to collect and predict precipitation and weather data, such as levels where flooding is likely to occur and highest recordings of crest levels. Four river gauges were analyzed to understand patterns of flood and drought throughout the Dan River watershed. Locations include Smith River near Woolwine VA, Smith River in Eden NC , Dan River in Danville VA , and Dan River in South Boston VA.
River Gauge Observations:
Gauge Location | Level where Flooding Occurs | Highest Record Crest |
|---|---|---|
Woolwine | 8 - 13 feet | 16.1 feet |
Eden | 12 - 18 feet | 19.3 feet |
Danville | 21 - 32 feet | 30 feet |
South Boston | 18 - 34 feet | 33.4 feet |
Drought and Flood Patterns:
Extreme Flooding Events:
The Deluge of August 1940
One of the most catastrophic flooding events to occur in the area, with extreme rainfall over a short period of time from remnants of multiple tropical storms. There was around 15 to 20 inches of rainfall over the course of a few days, causing flash flooding and landslides that took out bridges, roads, buildings, and even sections of train tracks. Over 50 people died, 1000 were people displaced.
Hurricane Agnes, June 1972
A category 1 hurricane that weakened upon approaching the watershed, but then combined with another storm system to send heavy rainfall to the area. Caused major flooding in the Dan River and its tributaries, with rainfall up to 10 inches.
Hurricane Fran, September 1996
A category 3 hurricane that weakened into a tropical depression. Windspeeds reached up to 115 miles per hour, with rainfall around 6 to 10 inches.
Hurricane Michael, October 2018
A category 5 hurricane with heavy rainfall, tornadoes, and high wind speeds up to 160 miles per hour. While total rainfall was only around 3 to 6, towns in low elevations, like Danville and South Boston, experienced extreme flash flooding caused damage to the agricultural industry and infrastructure.
Tools and Equipment
As defined by the Environmental Protection Agency, a watershed tool is "any method, technique, or equipment used to evaluate, correct, or prevent a chemical, physical, or biological impairment or threat to a watershed (including ground water and surface water)." Watershed tools can be divided into a range of categories, such as data collection, modeling, and communication.
