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Nickajack dam

The Great Replacement

TVA’s Nickajack Dam was built to replace the ever-leaking Hales Bar Dam, which—built as it was in 1913—held the distinction of being the first dam ever on the main stem of the Tennessee River.

Nickajack Dam is unique in that it is the only dam in the TVA system built to replace an existing hydro facility. It was built in the mid-1960s to replace the old and leaking Hales Bar Dam, which was located 6.4 miles upstream.

Hales Bar held the distinction of being the first main-river, multipurpose dam EVER built on the Tennessee River. In order to improve navigation on the Tennessee and provide electricity to the city of Chattanooga, Jo Conn Guild, Sr.—a Chattanooga engineer—promoted the construction of a privately funded lock and dam in exchange for the rights to the dam’s hydroelectric power. Congress passed the enabling legislation for this action in 1904, and with funding from Chattanooga entrepreneur Charles E. James and New York financier Anthony Brady, the Chattanooga and Tennessee River Power Company was formed to oversee the project. Construction of the Hales Bar began in October of 1905.

Difficulty at the Beginning

The construction of the dam and powerhouse was the largest development of its kind ever undertaken in the region. The dam itself was to measure almost one-half mile long and sixty-three feet high. The project would employ over 5,000 men, requiring the construction of a small village to feed and house the workers. While the dam was originally slated for completion in 1909, numerous difficulties delayed construction. Flooding of the site caused work to lag, while leakage issues related to the soft bedrock foundation played havoc with the schedule.

The project was finally completed four years later with much fanfare. In fact, the initial operation of the Hales Bar Hydro Plant on November 13, 1913, was characterized by many accounts as “the greatest celebration that Chattanooga has ever known.”

Unfortunately, leaks in the dam appeared almost immediately after completion. In 1919, engineers attempted to minimize the leakage by pumping hot asphalt into the dam’s foundation. This process was temporarily successful, but by 1931, a study showed the dam was leaking at a rate of 1,000 cubic feet per second. By this time, the Chattanooga and Tennessee River Power Company had merged with several other companies to form the Tennessee Electric Power Company (TEPCO), the largest private-sector electrical power monopoly in Tennessee’s early 20th century history. The Tennessee Valley Authority (TVA) acquired Hales Bar Dam in August 1939 when it purchased the assets of TEPCO.

As Hales Bar became part of the TVA system of locks and dams, it was nothing but trouble for the agency’s engineers. By 1963, a Knoxville News-Sentinel article noted that “ever since the dam was built, it has leaked . . . . After spending well over $3 million over the years trying to plug the leaks, TVA has decided to chuck the whole idea, tear down the old dam and build a new one the agency can trust.”

Holding Together

TVA chose a site about 18 miles west of Chattanooga—where the river swings close to the intersection of the Tennessee, Alabama and Georgia state lines—as the location of the new dam. It was named Nickajack after the ancient Indian town of the same name. The dam would generate more electricity than Hales Bar, and—with two navigation locks—offer uninterrupted passage of river traffic.

But most importantly, Nickajack Dam would rest on a different rock formation than the cavernous limestone foundation under Hales Bar, ensuring that the same kind of leakage would not be a problem.

Construction began on Nickajack in 1964 with initial power operations occurring in February 1968. TVA built the two navigation locks first, thereby assuring a steady flow of barge traffic. All salvageable parts—such as gate locks, spillway gates, and generators—were moved from Hales Bar and repurposed

As the finishing touches were being made to the $70 million Nickajack project in 1967 and 1968, the 1000-foot wide spillway of Hales Bar was being demolished. All that remains of Hales Bar today is the powerhouse.