Dye Tracing and the Effects of Infrastructure in Hidden River Cave, Horse Cave, KY

Hidden River Cave is a stream cave system found in Horse Cave, KY with continuous water flow of its two branches, Wheet River and East River. The infrastructure of the city of Hose Cave, KY was originally designed to utilize natural sinkholes for drainage of all wastewaters. The city uses many of these, now modified, sinkholes for wastewater disposal and storm water drainage. Historically, Hidden River Cave has been severely impacted by unmonitored dumping of contamination. To better understand and identify specific flow paths from sinkholes and infrastructure into Hidden River Cave, this study documented various sinkholes and other infrastructure, such as storm drains, sewer systems, and other undocumented pipes, that could send water from the surface to Hidden River Cave. The study focused on using fluorescent dyes injected into four sites in order to document how the water carrying these dyes moved through the cave system. These dyes were identified using charcoal dye receptors placed at six locations within Hidden River Cave. Additionally, passage cross-sections of two major branches of the cave were measured, while depth and velocity measurements were taken to calculate the discharge of the river in these branches of the cave. Dye trace results identified two flow paths and hypothesized a small groundwater basin based on the detection of various dyes within the cave from multiple injection sites. Discharge results appear to agree with the flow path interpretation derived from the dye traces. The most significant findings of this research include: 1) identifying multiple flow paths from various injection points, 2) determining the relationship between discharge of the Wheet River and East River in Hidden River Cave, and 3) hypothesizing a flow route based on a lack of detection from a previously unidentified injection point. These findings improve the understanding of the relationship between surface water catchment in the city of Horse Cave and the flow into Hidden River Cave.