A Tennessee Valley Authority repair project will kill fish at Raccoon Mountain near Chattanooga following maintenance work last month that also killed fish in the same mountaintop reservoir.
TVA is repairing a damaged seal at Raccoon Mountain. A statement Monday said the damage was discovered during the maintenance work.
In both cases TVA said some fish are stranded above the water level.
Dead fish will not be removed but will be left to decompose, partly to avoid risk of injury for employees who would have to collect them from deep silt.
The utility said natural processes will take over with little to no effect on remaining fish or wildlife.
TVA has notified wildlife and conservation agencies and will pay the state for the value of the fish.