Original caption reads: The force of falling water becomes electric power at Norris Dam -- A portion of the switchyard and powerhouse at the Tennessee Valley Authority's Norris Dam may be seen in the foreground, while beyond, the waters of the Clinch River cascade 207 feet down the face of the spillway section - a drop almost 40 feet greater than Niagara Falls. TVA engineers raised the 14-foot steel drum gates atop this spillway in January 1937 to prevent water from reaching the already swollen Ohio and Mississippi Rivers. Norris Dam, completed in 1936, helps control seasonal floods on the Tennessee and Mississippi Rivers, aids navigation in months of low flow and provides for the incidental production of electric power.