|The Coal River Watershed covers an area of some 890 square miles in southern West Virginia of which 863 square miles was investigated in this study. Both online and field data were collected over period from January 13, 2009 to January 13, 2010. The basin was studied as
a closed system having an input, which was precipitation, and outputs, rainfall interception,evapotranspiration, and stream discharge that was separated into base flow and overland flow.
The effective rainfall of the watershed was calculated using the Thiessen polygon method to be 42 inches for the year, 48% of that water discharged by the Coal River, 33% intercepted by
foliage, and 19% lost due to evapotranspiration.
The stream flow was separated into overland and base flow both manually and using digital filtering. About 60% of the stream discharge is from groundwater and 40% from overland flow. During months of larger rainfall the base flow is less, and for low rainfall months the base flow higher.