Mapping karst groundwater flow paths and delineating recharge areas for Fern Cave, Alabama through the use of dye tracing

Fern Cave in Jackson County, Alabama is the longest and deepest cave in Alabama with over 15 miles of cave passages and 536 feet of depth. The cave is cooperatively managed by the U.S. Fish and Wildlife Service and the Southeastern Cave Conservancy. At least three different streams flow through the cave including the Surprise, Lower North, and Bottom Cave streams. Two of these streams, Lower North and Bottom Cave, merge together in the lower portions of the cave system while the Surprise stream remains independent of the others. These streams then appear as resurgences at springs along the Paint Rock River near the base of Nat Mountain. Recent bio-inventories have shown the cave to be one of the most bio-diverse caves in the Southeastern United States with a total of 113 taxa documented including 25 cave obligates. The cave is also a habitat for several federally listed species such as the Gray Bat (Myotis grisescens) and the Alabama Cave Shrimp (Palaemonias alabamae). Because of the biological significance of the cave, an effort to delineate a recharge area for the cave began in 2019 when a partnership was formed between U.S. Geological Survey, Kentucky Geological Survey, and the U.S. Fish and Wildlife Service. A delineated recharge area would allow land managers to know what areas directly influence water quality and water quantity within the various streams in the Fern Cave System. From December 2019 through May 2021 a total of 14 dye injections were conducted which delineated a recharge area of 1.73 square miles, lying primarily along the western escarpment of Nat Mountain.

This data release contains shapefiles that relate to dye injection locations, monitoring sites, dye traces, and delineated recharge areas.  All files were created in ArcGIS Pro and each shapefile contains associated attributes for the features contained within. Layer files are included with the datasets to match symbology found in figures in the accompanying report. All shapefiles and layers were created and modified in ArcGIS software. More information is contained within the README.txt file.  For a full description of the methods to create these files, see Process Steps in "Fern_Metdata.xml" metadata file.