HYDROGEOLOGY OF THE HIDDEN RIVER GROUNDWATER BASIN, HORSE CAVE, HART COUNTY, KENTUCKY

Subsurface drainage basins are highly interconnected in karst regions, as groundwater is quickly transported through conduits created by the dissolution of carbonate bedrock. South-central Kentucky is a classic example of a well-developed karst landscape and includes the longest-known cave system, Mammoth Cave. The Mammoth Cave karst aquifer contains 28 major groundwater basins, of which the Hidden River groundwater basin has been severely impacted by anthropogenic contaminants. Hidden River Cave, located in the city of Horse Cave, Kentucky, forms one of the main tributaries of the Hidden River groundwater basin that spans parts of Barren and Hart Counties. Hidden River Cave formed in Mississippian-aged carbonates and consists of a dendritic network of canyons and collapsed domes. A major trunk stream flows through the cave that contributes recharge to the Mammoth Cave aquifer. Poor land-use practices, including changing residential, commercial, and industrial boundaries, have lead to the contamination of the cave stream. As a result, the hydrogeology of the Hidden River groundwater basin has been studied extensively using fluorescent dyes. Recent developments in groundwater resource management have improved cave conditions; however, land-use boundaries in Horse Cave that intersect with areas of recharge may still introduce contaminants into the groundwater system. This research characterizes recharge to Hidden River Cave using geographic information systems analysis and fluorescent dye tracing. Additionally, land-use in Horse Cave is evaluated, as groundwater resource management varies between municipalities and counties. This research provides a more detailed description of the Hidden River groundwater basin and provides scientific data to the City of Horse Cave and the American Cave Conservation Association for more informed management of Hidden River Cave.