Mapping karst groundwater flow paths and delineating recharge areas for springs in the Little Sequatchie and Pryor Cove watersheds, Tennessee

The Little Sequatchie River and Pryor Cove Creek watersheds are located in southern Tennessee and drain the eastern escarpment of the Cumberland Plateau to the Sequatchie River.  The Little Sequatchie River has the largest drainage area of any Sequatchie River tributary, with over 130 square miles in the topographic confines of the watershed.  The hydrology of both watersheds has been largely altered by karst processes which have caused the majority of the streams to sink into the sub-surface, typically at the contact between the Mississippian Pennington Formation and the underlying Mississippian Bangor Limestone. A collaborative project between the U.S. Geological Survey and the U.S. Fish and Wildlife Service began in 2021 to map the karst groundwater pathways in the valleys and to delineate recharge areas for several springs.  One of these springs, Owen Spring (also known as Sequatchie Cave), is critical habitat for two Species of Conservation Concern, Glyphopsyche sequatchie (Sequatchie Caddisfly) and the Federally Threatened and Endangered Pyrgulopsis ogmorhaphe (Royal Marstonia).  The Little Sequatchie River also provides water for agricultural practices and both the main stream and nearby springs serve as drinking water sources for nearby communities.  During the study a total of 25 dye injections were conducted over eight rounds from January 2022 through March 2023.  Dye traces from these injections have helped to delineate recharge areas for five major springs, ranging from 7.3 to 65.2 square miles in area. The majority of the dye traces have remained sub-surface (from sink point to recovery site) for significant distances with karst groundwater travelling several miles before resurfacing.  These traces also had rapid travel times, often travelling thousands of feet to miles per day.  The goal of this project was to provide scientific data related to karst groundwater pathways and spring recharge areas that state and federal agencies can use to make informed decisions on the protection and preservation of this unique and vulnerable karst system.  

The data in this data release consists of shapefiles of points, polylines, and polygons that represent data related to dye injections, monitoring sites, dye flow paths, spring recharge areas, and recharge area boundaries.  Layer files have also been included with the dataset to standardize symbology and match figures in the related report.