Tennessee Code Title 69. Waters, Waterways, Drains and Levees § 69-11-113

Certificates of approval shall be for a definite period of time, not to exceed five (5) years, as determined by the commissioner and stated on the certificate. In determining the period of approval, the commissioner may take account of any circumstances pertinent to the situation, including, but not limited to, the size and type of dam, topography, geology, soil conditions, hydrology, climate, use of the reservoir and the lands lying in the floodplain downstream from the dam, and the hazard category of the dam.