sentences:  In 1949, TVA increased the dam's generating capacity and equipped the spillway with radial gates that helped extend the Hales Bar Reservoir's navigation channel all the way to the base of Chickamauga Dam.In the late 1950s, however, boils began to appear in the water below Hales Bar Dam, and an investigation showed the dam was again leaking, this time at an alarming .Dye tests carried out in 1960 suggested that many of the leakage channels had interconnected, increasing the possibility of a future dam failure.