Introduction to the Rockcastle River Watershed 

Article by Jim Hays, Rockcastle River Project Director, Kentucky Chapter of the Nature Conservancy

The Rockcastle River watershed is in southeastern Kentucky and covers part of five counties: Laurel. Jackson, Rockcastle, Clay and Pulaski.

The first, recorded glimpse of this land is revealed by the diary of Dr. Thomas Walker, who in 1750, explored what is now known as the Rockcastle River. He told of gloomy forests, towering clifts, clear mountain streams, abundant fish, wildlife, rattlesnakes, and acres of massive tree trunks laid low in a tangled mass by blow-downs. He also told of the discovery of log cabins built by native Americans. Some parts of the Rockcastle watershed could still be described that way, but parts of the watershed have been negatively impacted by resource extraction, high-density development, poor agricultural practices, and in many cases, carelessness. A portion of the Rockcastle River has been designated a wild and scenic river and contains federally endangered species.

The Rockcastle is classified by the Kentucky Division of Water as both a High Quality Water and an Outstanding Resource Water, having many tributaries. Some of them flow through the towns of London, McKee, Livingston and Mt. Vernon, crossing under I-75 and paralleling US 25 and a hundred other roads. Many of the tributaries like Horse Lick Creek, Crooked Creek or Raccoon Creek are relatively isolated and have historic and colorful pasts. The relatively clean water found in the Rockcastle allows it to host a diverse fish and mollusk fauna including several federally listed species. Water quality problems do exist in the form of excess siltation due to mining and poor farming and logging practices.

This area is underlain by sedimentary rock layers of Mississippian and Pennsylvanian age. The rock units are composed primarily of sandstone, limestone, and shale, with scattered occurrences of siltstone, conglomerate, and coal. The Rockcastle River was once a tributary to the Cumberland River, but now Lake Cumberland begins at the confluence of the Rockcastle and Cumberland Rivers. The primary land use within the watershed is timber production and agriculture. Coal strip-mining and limestone quarries also occur in the area.

The Rockcastle River watershed has an extensive karst system. Most of the system is evidenced in the Crooked Creek and Horse Lick Creek watersheds. Much of the upper reaches of these streams sink only to reemerge again from one hundred yards to one mile downstream. Many of the caves contain federally listed bat species. One of the caves has an average winter population of over 1,000 Indiana bats. Bowman Saltpeter Cave has six different species of bats including Indiana bats and Virginia Big-eared bats.

Most of the Rockcastle River watershed lies in the proclamation area of the Daniel Boone National Forest. For this reason the steep topography found in the lower reaches of the Rockcastle, a large percentage of the watershed is wooded. There is extensive farming activity in the Roundstone Creek tributary and the towns of Livingston, Mt. Vernon, and part of London drain into the Rockcastle.

It is important to note that not only are there federally listed endangered species in the Rockcastle River watershed, but to be cognizant of the reasons that they continue to exist there and not in other places.

Targets for Protection 

The primary targets for protection and/or restoration in the project area include mussels and the terrestrial and aquatic ecosystems within the watershed and the rich biodiversity they support, which are threatened by a host of human activities. These activities include point and nonpoint source pollution, conversion to agriculture, primary home development, development of roads or utilities, livestock management and production practices, fire suppression, and silvicultural and agricultural practices. 

Mussels

Although native Americans used mussels for food and fashioned mussel shells for implements and adornments, the Rockcastle River mussel fauna had changed little for thousands of years prior to European settlement. However as settlers moved westward, aquatic ecosystems were dramatically altered and the diverse mussel fauna that once flourished in the region began to decline. The mussel population in the Rockcastle has been adversely affected by impoundment, siltation, coal mining, and physical destruction of mussel habitat by ATV’s. Few other wide-ranging faunal groups in the continental United States have experienced this degree of loss within the twentieth century.

The Conservancy and its partners are striving to improve water quality in the Rockcastle River watershed, through strategies involving land acquisition, education, farm bill programs, and elimination of point sources of pollution like straight pipes, malfunctioning package plants, and the improvement of municipal waste disposal systems. 

Bats

The Rockcastle watershed has three species of federally endangered bats. The gray bat is two inches long with an 11-12 inch wingspan. It was once abundant in caves of the southeastern United States. This bat is extremely sensitive to disturbance. The Virginia big-eared bat is a four inch long brown bat with a 12-inch wingspan and ears that measure nearly 1 ½ inches in length. This species is one of the most secretive bats and for this reason relatively little is known about its behavior. The Indiana bat is a small brown bat that is less than two inches long. The Rockcastle watershed has numerous caves in which these bats winter. Caves and forest hibernacula are high priority for protection by The Nature Conservancy.

Because bats are often highly social and form large colonies, they are uniquely susceptible to the loss of critical hibernation and reproduction sites, through the closure of cave and mine entrances, human disturbance, and the elimination of colonies from buildings.

Author: Jim Hays, The Nature Conservancy
Last Updated: August 13, 2008