Three big TN dams — Boone, Center Hill, Pickwick — getting repair work

Seven years after an historic flood underscored threats to dams across Tennessee, three of the state’s largest water-control structures face millions of dollars in needed repairs and improvements to deal with hazards ranging from earthquakes to sinkholes, reports the Commercial Appeal.

Although none is in as dire shape as the flood-damaged Oroville Dam in California, the federally operated Boone, Center Hill and Pickwick dams are being significantly reinforced through long-term projects, with water levels lowered in two of them. The Tennessee Valley Authority, which runs the Boone and Pickwick dams, and the Corps of Engineers, which operates Center Hill, say they have adopted aggressive safety measures to protect downstream residents.

The three dams are among the largest — and potentially most dangerous — in Tennessee. But they’re not the only ones that have raised concerns among dam-safety officials. Flash floods that swept across 49 counties in May 2010 led to the failure of seven dams statewide and caused damage at several others. More than a dozen dams in West Tennessee alone required significant repairs.

All told, there are more than 1,200 dams in Tennessee, including 273 rated as “high hazard” because their failure likely would lead to the loss of life. But nearly half of the state’s dams, including 69 rated as high hazard, are exempt from regulation and government inspections because they’re classified as farm ponds.