The Tennessee Valley Authority is a federal agency that controls the electricity, irrigation and flood control from the dams and reservoirs along the Tennessee River.
An example of the Tennessee Valley Authority is the agency created by President Roosevelt in 1933 to provide cheaper electricity.
(proper) A federal corporation organized in 1933 to provide cheap electric power, flood control, irrigation, etc. by developing the entire basin of the Tennessee River, esp. by building dams and reservoirs.