Modeling and Evaluating the Influences of Class V Injection Wells on Urban Karst Hydrology

The response of a karst aquifer to storm events is often faster and more severe than that of a non-karst area. Many urban karst areas (UKAs) are plagued by groundwater flooding resulting from the highly permeable and diffusive aquifers. In UKAs, municipalities often struggle with flood management, because traditional strategies are ineffective. The City of Bowling Green (CoBG), Kentucky is a representative example of an area plagued by karst flooding, despite several decades of research and work done to understand and mitigate the issues. The CoBG, like many UKAs, uses Class V Injection Wells to reduce the severity of flooding. The overall effectiveness, siting, and flood impact of Injection Wells in UKA’s are still lacking; their influence on groundwater quantity and quality are evident from recurring problems of flooding and groundwater contamination. The purpose of this research to examine Class V Injection Wells in the CoBG to determine how Injection Well siting, design, and performance influence urban karst hydrology. The study uses high resolution monitoring, hydrograph recession analysis, geostatistical techniques, and hydrologic modeling (WMS-GSSHA) to evaluate Injection Well and spring responses during baseflow conditions and storm events. Through quantifying the hydrodynamic properties of the karst aquifer and the influences from the surrounding environment, it is possible to establish a relationship between precipitation events and the drainage capacity of the Injection Wells and the underlying karst system, as well as explore possible siting issues contributing to the efficiency of the system.