The valley, 41,000 square miles in area, receives an average of 52 inches of rain a year.  In terms of water discharged into the Ohio and Mississippi, the Tennessee River is about equal in size to the Missouri.

The Tennessee Valley Authority has harnessed the river with a multi-purpose system of dams and reservoirs which regulates floods, improves navigation, and generates electric power.

High dams on the tributaries create large storage reservoirs which hold back flood waters, releasing them when necessary to maintain navigation depths downstream, and at the same time generating electric power.  The system also helps protect the Lower Ohio and Mississippi Valleys.

The nine main river dams, with their locks, form a navigation channel 850 miles long, from Knoxville to the Ohio River.  An important arm of the nations inland waterway system connecting 20 states.

Having developed virtually all the river's power resources, TVA has built huge coal-burning steam electric plants to help serve the region's growing power needs.. TVA power is sold at wholesale to cities and rural electric cooperatives which, in turn, distribute it at retail to homes, farms, business, and industry.  A few industries and U S Government diverse installations that use large amounts of power and served directly by TVA.  The largest of these using more power than a great city, are the atomic plants at Oak Ridge, Tennessee, and Paducah, Kentucky.