In the late 1970s, Duncan engaged in a protracted legislative struggle with environmentalists over the Tennessee Valley Authority's construction of Tellico Dam, on the Little Tennessee River, in Duncan's district.
dam | Hoover Dam | Aswan Dam | Grand Coulee Dam | Kinzua Dam | Bonneville Dam | Grand Rapids Dam | embankment dam | Beaver Dam, Arizona | Merowe Dam | Beaver Dam, Wisconsin | Three Gorges Dam | Mangla Dam | Beaver Dam | Aswan Low Dam | Akosombo Dam | Shasta Dam | Itaipu Dam | Fort Peck Dam | Fontana Dam | Dam Square | Chickamauga Dam | Yacyretá Dam | Wilson Dam | Tiga Dam | Temenggor Dam | Tarbela Dam | Tai Dam | Tabqa Dam | Safe Harbor Dam |
Determined to have the Tellico Dam completed, Senator Baker and Representative John Duncan, Sr. rejected the economic analysis and attached a rider into the Energy and Water Development Appropriation Act in July 1979 directing TVA to complete the construction of the Tellico Dam.