From the Tennessee Valley Authority:
TVA To Accelerate Boone Reservoir Drawdown for Inspection Work
The Tennessee Valley Authority is accelerating the annual drawdown of Boone Reservoir near Johnson City, Tenn., after a sink hole was discovered near the base of the earthen embankment and a small amount of water and sediment was found seeping from the river bank below the dam.
“Public safety is our top priority and we are continuously monitoring the dam to ensure it is safe,” said John McCormick, TVA vice president of River Operations. “The accelerated drawdown is out of an abundance of caution. Our engineers want to be sure we understand what caused the sink hole and where the water and sediment is coming from.”
From the Johnson City Press:
Seepage at bottom of dam causes early lowering of Boone Lake
A chink in the Boone Dam’s armor has Tennessee Valley Authority officials starting the annual depth drawdown of Boone Lake about five weeks ahead of schedule.
When an Oct. 20 inspection of the dam revealed a sink hole — a common occurrence — TVA workers repaired it quickly. Six days later, an uncommon occurrence happened when seepage was found near the location of the sink hole at the base of the dam.
Seepage is not a good thing for an earthen dam - the situation, as they say, is developing...