Groundwater Yield Modeling In The Fractured Bedrock Aquifers Of The Blue Ridge Physiographic Province, Watauga County, North Carolina

Groundwater is a commodity that is used by the majority of residents of Watauga County, North Carolina (NCDENR 2001; NC Cooperative Extension 2001). The fractured bedrock aquifers that house the water that these residents access by wells have long been known to be highly heterogeneous and thus problematic at times for locating ideal areas to drill productive wells. In 1967, the United States Geologic Survey (USGS) published a paper written by Harry LeGrand (LeGrand 1967) that predicatively modeled groundwater availability for the Blue Ridge and Piedmont Provinces in North Carolina. The model used various categories oftopographic position and regolith thickness to assess how productive (in gallons per minute) a potential site would be. The language used for describing LeGrand's (1967) topographic categories is familiar but vague. This study uses digital elevation model (DEM) derived surfaces to quantify and replicate LeGrand's (1967) topographic categories in the Geographic Information System (GIS) environment and to test the model against a database of wells in Watauga County.