TVA logoBy the numbers8.73 – Inches of rainfall during in the Tennessee Valley watershed that drains through Chattanooga, or 76 percent more than normal47.6 – Inches of rainfall in Chattanooga so far this year, or 46 percent above normal$44 million – Estimated flood control savings for Chattanooga from TVA dams and flood control program1.858 – Gigawatthours of electricity generation in July from TVA hydro units, an all-time highSource: Tennessee Valley Authority
Chattanooga was spared an estimated $44 million of flood damage last month because of TVA’s network of dams and storage reservoirs.
With rainfall during July nearly twice its normal level across East Tennessee, the Tennessee Valley Authority projects the rain-swollen Tennessee River and its tributaries would have spilled out of their banks and damaged many developed properties in Chattanooga’s low-lying areas without TVA’s dams and storage lakes to hold back the floodwaters.
TVA spokesman Duncan Mansfield said July’s rainfall in the Tennessee Valley was the highest since 1967 and the fourth highest since precipitation record keeping began in 1890. Combined with heavy rains during the first half of the year, rainfall in Chattanooga so far this year totals nearly 48 inches, or 15 inches above normal, according to the National Weather Service.
Rainfall runoff from 20,000 square miles of land in East Tennessee, Northern Georgia, and western North Carolina and Virginia is funneled into the Tennessee River through Chattanooga. TVA operates 49 dams on the Tennessee River and its tributaries for flood control, hydroelectricity production, river navigation and lake recreation in its 7-state region.