Abstract
The Lost River Groundwater Basin located in south-central Kentucky may be one of the most thoroughly investigated karst basins in the US. Over the past 50 years, numerous studies have been conducted primarily due to the environmental challenges created by urban development on a well-developed sinkhole plain. The City of Bowling Green (pop. ~80,000) covers much of the basin but lies primarily in the northern, downstream reach nearest the main outlet of the system, the Lost River Rise. However, land use in the southern, up-gradient, portion of the basin is quickly changing from undeveloped and/or agriculture to industrial and residential. Due to local concerns of how large-scale residential development and the increase of impermeable surfaces could affect flooding in adjacent areas, Crawford Hydrology Lab (CHL) partnered with landowners and regulators to better understand the localized hydrology near the community of Richpond. Considering the Lost River basin had been delineated using dye tracing, potentiometric surface mapping, detailed lithological studies, cave survey, and geophysical techniques, basin boundaries were assumed to be correct and detailed sub-basin dye traces were conducted. Phase I traces in 2021 were inconclusive as dye was not recovered at any monitoring location. Recognizing the data gap in the interpreted basin boundaries, CHL broadened the scope and conducted a multi-phase dye trace investigation, using multiple dyes over several years, to reevaluate the Lost River Groundwater Basin boundary. Dye tracer tests conducted by CHL in 2023-2026 have now conclusively shown that roughly nine square kilometers of recharge area once attributed to Lost River Rise is indeed part of the Cloud Spring Basin and we present a new basin boundary map. This study directly informs planning and zoning, storm water management, and hazard mitigation. Results also infer that the complex lithology is still not fully understood in this area of the basin and warrants additional study.
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DOI
https://doi.org/10.5038/9781967518012.1024
Ongoing Dye Tracing Prompts Major Reevaluation of Groundwater Divides for the Lost River Karst System, Bowling Green, KY, USA
The Lost River Groundwater Basin located in south-central Kentucky may be one of the most thoroughly investigated karst basins in the US. Over the past 50 years, numerous studies have been conducted primarily due to the environmental challenges created by urban development on a well-developed sinkhole plain. The City of Bowling Green (pop. ~80,000) covers much of the basin but lies primarily in the northern, downstream reach nearest the main outlet of the system, the Lost River Rise. However, land use in the southern, up-gradient, portion of the basin is quickly changing from undeveloped and/or agriculture to industrial and residential. Due to local concerns of how large-scale residential development and the increase of impermeable surfaces could affect flooding in adjacent areas, Crawford Hydrology Lab (CHL) partnered with landowners and regulators to better understand the localized hydrology near the community of Richpond. Considering the Lost River basin had been delineated using dye tracing, potentiometric surface mapping, detailed lithological studies, cave survey, and geophysical techniques, basin boundaries were assumed to be correct and detailed sub-basin dye traces were conducted. Phase I traces in 2021 were inconclusive as dye was not recovered at any monitoring location. Recognizing the data gap in the interpreted basin boundaries, CHL broadened the scope and conducted a multi-phase dye trace investigation, using multiple dyes over several years, to reevaluate the Lost River Groundwater Basin boundary. Dye tracer tests conducted by CHL in 2023-2026 have now conclusively shown that roughly nine square kilometers of recharge area once attributed to Lost River Rise is indeed part of the Cloud Spring Basin and we present a new basin boundary map. This study directly informs planning and zoning, storm water management, and hazard mitigation. Results also infer that the complex lithology is still not fully understood in this area of the basin and warrants additional study.