Many of Tennessee’s largest caves are found in fluviokarstic terranes, where surface streams act as overflows for the cave streams. These cave streams are typically unmapped and often carry the entire dry-weather flow of the watershed. They sometimes resurge across watershed divides, complicating the implementation of watershed-based approaches to environmental regulation. Source water protection activities and Clean Water Act antidegradation policies in Tennessee are currently based, of necessity, on the assumptions that groundwater basins correspond to watersheds delineated by topography. Recently the dearth of information on groundwater basin boundaries and subsurface flow routes has led to considerable public debate, litigation, and an attempt by karst scientists to better inform the regulatory agencies.

The process of permitting wastewater discharges on the western escarpment of the Cumberland Plateau provides numerous examples of the difficulties faced in implementing watershed-based regulations in fluviokarstic environments. The decision to discharge wastewater effluent into Dry Fork Creek and through Rumbling Falls Cave resulted in a major effort by a consortium of karst scientists and speleologists to determine the potential impacts to the unique ecosystem of the Rumble River, which flows through the cave. Currently, legal action has blocked the discharge to Dry Fork Creek and alternatives are being considered. In the Yellow River case, the subsurface flow path of the upper Falling Water River, which flows into China Cave in the adjacent Calfkiller River watershed, has been better defined. The upper Falling Water River has been severely impacted by the Monterey, Tennessee sewer plant and collection system at various times during the past two decades.