Many of the Cumberland Plateau’s beautiful attractions and much of its biological diversity can be credited to one of its most important natural resources: water. As rivers and streams cut downward through the Plateau’s sandstone into the more easily erodible rock layers below, they created the dramatic gorges, cliffs, arches, rock shelters and waterfalls we see today.

Plateau streams form the headwaters of multiple rivers, including the Emory and Big South Fork. The Emory River watershed contains four main streams – the Obed River, the Upper Emory River, Clear Creek, and Daddys Creek. The Obed River starts near Crossville, TN, and flows easterly through a narrow valley toward its junction with the Emory River. The two principal tributaries, Clear Creek and Daddys Creek, join the Obed a few miles above its mouth. Parts of the Emory/Obed river system were designated as part of the National Wild and Scenic River network in 1974. This designation acknowledged the aesthetic beauty and biological health of the Emory/Obed system. The Obed River is one of the best whitewater rivers in the eastern United States.

The confluence of the Clear Fork River and the New River is called the Big South Fork. The Big South Fork watershed is the third largest tributary to the Cumberland River, draining an area of 1,382 square miles as it flows northward from in Morgan, Scott, and Fentress counties into Kentucky. The watershed provides habitat for 26 species of mussels of which seven are federally endangered or threatened. It is also responsible for forming some of the most memorable gorges, canyons and rock cliffs in the Cumberlands, many of which are located within the Big South Fork National Recreational Area.

Because water does not readily flow through the Plateau’s sandstone cap, water levels can rise quickly during storms. During these natural flood events, streambeds are scoured of sediment and riparian plants are flooded. These natural processes provide habitat and nutrients for freshwater mussels and riparian plants. Many of the fish and mussel species found here are federally endangered and very sensitive to changes in water flow and quality. For example, Blackside dace and the Cumberland elktoe mussel both require streambed habitat comprised of clean gravel or cobbles. If streambed gravel fills in with fine sediment, Blackside dace have difficulty spawning and mussels’ filters can become clogged, preventing their ability to feed. High flows associated with natural floods keep these streambeds free of fine sediment and support the health of these and other fish and mussel species. (For more information on species of the Cumberlands visit our species page). This process achieves a delicate balance between the natural floods necessary to maintain clean streambed habitat and the intensive flooding associated with urbanization that can dislodge mussels and riparian plants.