TVA dams and reservoirs help “keep floods away from the people,” but they cannot prevent all flooding. For this reason, TVA also tries to “keep the people away from floods” by promoting the wise use of floodplains and preventing development that can adversely impact operation of the reservoir system for flood damage reduction. (Floodplains are lands bordering rivers and streams that are normally dry but are covered with water during floods.) The focus is on the lands and projects TVA holds in stewardship and on the floodplains along the rivers and streams regulated by TVA dams.
A key component of TVA’s floodplain management effort is promoting awareness of flood risks. TVA uses historic data to determine which areas fall within the 100-year floodplain. People living in these areas have a 1-in-100 chance of being flooded in any given year (which is different from being flooded once every 100 years). Essentially, this means that if they choose to build there, they do so at their own risk.
Section 26a of the TVA Act gives TVA control over structures built out into the waterway that could impact flood damage reduction, navigation, and public lands, such as docks and marinas. (Learn more about TVA’s shoreline construction permitting process.) But TVA does not have regulatory authority over structures in the floodplain. The responsibility for implementing and enforcing floodplain zoning resides largely with local governments.