Hales Bar Dam was a hydroelectric dam once located on the Tennessee River in Marion County, Tennessee, United States. The Chattanooga and Tennessee River Power Company began building the dam in 1905 and completed it in 1913, making Hales Bar one of the first major multipurpose dams and one of the first major dams to be built across a navigable channel in the United States.
In 1939, the Tennessee Valley Authority assumed control of Hales Bar Dam after purchasing TEPCO's assets. TVA spent two decades trying to fix a leakage problem that had plagued Hales Bar since its construction, but after continued leakage, and after it was determined that expanding the dam's navigation lock would be too expensive, TVA decided to replace the dam by building Nickajack Dam 6 miles (9.7 km) downstream in 1968.
Location and Capacity:
Hales Bar Dam was located along the Tennessee River at just over 431 miles (694 km) above the river's mouth, near the southwest end of the Tennessee River Gorge. The dam's reservoir extended up the river through the gorge all the way to Chattanooga, and had 162 miles (261 km) of shoreline. Before the construction of Hales Bar, this was a particularly unpredictable and dangerous section of the river, with numerous navigation obstacles. Downstream from the dam site, the river begins to steady as it enters the hills and flatlands near Guntersville.
Hales Bar Dam was 113 feet (34 m) high and 2,315 feet (706 m) long, and its spillway had a combined discharge capacity of 224,000 cubic feet per second (6,300 m3/s). After improvements by TVA in 1949, the dam had a generating capacity of 99,700 kilowatts. The dam's lock, which went into operation on November 1, 1913, was 60 feet (18 m) by 260 feet (79 m), and its 41-foot (12 m) lift was the highest in the world at that time.