The Tennessee Valley Authority (TVA) in the US is to conduct detailed analysis and testing at the Pickwick Landing Dam after a recent inspection suggested there was a remote chance a large earthquake could damage the structure.
The Authority said it was accelerating the annual drawdown of the Pickwick Landing Reservoir located in West Tennessee, Northeast Mississippi and Northwest Alabama as a result of a recent "health check" inspection. Initial results from testing and core drilling suggested the remote possibility the earthen embankment south of the concrete portion of the dam could be damaged. Lower lake levels will allow TVA to conduct more detailed analysis and testing to determine what will be necessary to strengthen the south embankment against large seismic events. The Pickwick Landing area is only a few hundred miles from the New Madrid Seismic Zone along the Mississippi River.
“Public safety is our top priority," said John McCormick, TVA vice president of River Operations. "Because large earthquakes can't be predicted, we're taking immediate action to enhance the continued safety of the public and our employees."
TVA began "health checks" of its 49 dams more than a year ago as part of a continuous improvement program. The study checks the integrity of the concrete and earthen embankments against today's stringent industry standards.
Pickwick Landing Dam was designed and constructed in the 1930s. The concrete portion includes the powerhouse, spillways and two navigation locks with long earthen embankments on each side. The south embankment is about 4000ft long.
