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National Water Quality Assessment Program (NAWQA)

Tennessee River (TENN) Basin Study

Location of Tennessee River Basin

Welcome to the Tennessee River basin. Please explore either of the following links:

Upper Tennessee River Basin

Lower Tennessee River Basin

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The Tennessee (TENN) River Basin encompasses an area of 40,890 square miles, making it the largest tributary to the Ohio River. The Tennessee River flows through portions of seven states: Virginia, North Carolina, Tennessee, Alabama, Georgia, Mississippi, and Kentucky. From its origin high in the Appalachians to the confluence with the Ohio River, the Tennessee River spans more than 850 linear miles. The highest point in the Basin, located at Mount Mitchell, North Carolina (6,684 feet), is the highest peak east of the Mississippi River. Once a free flowing river, the natural character of the Tennessee River has been significantly altered during the last eighty years. Between the 1920's and 1960's, 49 dams were constructed along the main stem and tributaries. Dams located along the main stem function as "flow-through" reservoirs that improve river navigation and generate hydroelectric power; whereas dams on the tributaries function as large storage impoundments used primarily for flood control. Other alterations include the merger of the Mobile and Tennessee Rivers via the Tennessee-Tombigbee Waterway, which provides a navigational route between the Mobile and Tennessee Rivers and the Gulf of Mexico.

The Tennessee River Basin is most notable for its abundance and diversity of freshwater fishes. Recognized as one of the most diverse rivers in North America, the Tennessee River supports about 240 fish species. Only the Mobile (236 species), Cumberland (186 species), Roanoke (82 species), and Conasauga (78 species) Rivers compare in numbers of fish species. Along with its unmatched diversity, the Tennessee River Basin also has one of the most imperiled faunas. The U.S. Fish and Wildlife Service currently lists 51 aquatic species (fish and mollusks) as either threatened or endangered.

The Tennessee River also hosts the most diverse mollusk fauna in North America. The town of Muscle Shoals, Alabama, derived its name from a series of islands and shoals created by the mounds of mussel shells deposited by the Cherokee Indians. Approximately 102 native freshwater mussels have been recorded within the Tennessee River Basin. Most of the present-day fauna are confined to the Clinch and Duck Rivers. The diversity of mollusks and fish in the Tennessee River is a reflection of the unique aquatic habitats that exist throughout the Basin.

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Last Modified 8/24/01