The drainage basin of the Cumberland River encompasses an area of 17,914 square miles, making it by far the largest watershed with an origin in Kentucky. Of this area, the Upper Cumberland River drains approximately 5,180 square miles of southeastern Kentucky.
There are approximately 10,200 miles of streams in the Upper Cumberland River watershed. The basin is bordered on the east by the Cumberland and Black mountains, which form the border with Kentucky and Virginia.
The northern and western borders are the drainage divides of the Kentucky and Green rivers, respectively. To the south, the basin extends into Tennessee where it borders the Tennessee River Valley. The general topography varies greatly.
The eastern half of the basin lies in the Eastern Mountains and Coal Field Physiographic region, which is part of the larger Cumberland Plateau.
The western half of the basin lies in the Mississippian Plateau region. A small portion of the northern tip lies in the region.
The elevation of the basin ranges from 540 feet above sea level in Monroe County along the Cumberland River to Kentucky’s highest point of 4,145 feet on Big Black Mountain in Harlan County.
This area includes all or part of 20 counties in Kentucky: Bell, Harlan, Letcher, Knox, Clay, Whitley, Laurel, Jackson, Rockcastle, McCreary, Pulaski, Lincoln, Casey, Russell, Wayne, Adair, Clinton, Metcalfe, Monroe and Cumberland.
Kentucky cities in the basin include Barbourville, Harlan, Pineville, Williamsburg, London, Somerset, Mount Vernon, Monticello, Jamestown, Burkesville, Albany, McKee, Middlesboro and Corbin, plus numerous smaller communities. Estimates from the 2000 Census show the population of the basin is roughly 335,000.
There were approximately 1,470 miles of streams assessed in the basin for a water quality study. Of these, about 208 miles of streams were found to be not supporting one or more of their designated uses. There were also about 161 miles partially supporting their designated uses. This leaves about 1,100 miles, or about 75 percent, of the streams fully supporting designated uses. Of those streams fully supporting, more than 150 miles of water have been declared as “exceptional.” Exceptional waters are those that have either a fish or macroinvertebrate community that is considered “excellent.”
In addition to the streams assessed, there were 13 lakes or reservoirs assessed for a total of 62,702 acres of water. Only one lake, Corbin City Reservoir, was determined to be not supporting all of its designated uses. Three lakes, including Lake Cumberland, were found to be partially supporting their designated uses. The remaining nine lakes assessed were found to be fully supporting designated uses.