The Tennessee Valley Authority (TVA) recently opened a newly installed spill gate at Nolichucky Dam and successfully lowered the reservoir – in only two hours – more than a foot below the spillway crest elevation of about 1,241 feet.
“The new gate performed as expected and will allow us to look closely at this dam to ensure that it meets TVA standards for dam safety,” said Jim Bryant, senior program manager for dam safety with TVA.
A preliminary inspection of the face and toe of the dam was conducted while the water was down. Steep slopes and rocky shorelines limited access to the dam, but TVA dam safety personnel used a high-tech amphibious vehicle loaded with sonar equipment to access the toe of the dam. This equipment will provide more data and allow more extensive inspections in the future.
Nolichucky Dam was built in 1913 and acquired by TVA in 1945. Located on the Nolichucky River just southeast of Greenville, Tenn., it impounds Davy Crockett Reservoir. The dam stopped generating hydropower in 1972. After ongoing maintenance issues, its old spill gate had been permanently closed in 1995 by installing a reinforced concrete bulkhead on its upstream side.
TVA’s increased focus on dam safety calls for more thorough inspections, which is now possible using the new gate and other technological tools and machinery. The gate installation was a joint effort between TVA’s dam safety, environmental compliance and operations, power services shops, and generation construction projects services & facilities teams.
TVA also performs monthly, biannual and annual inspections of all of its river dams to identify any potential issues or concerns. More thorough detailed inspections are performed every five years by a diverse team of dam safety subject matter experts, operators and inspectors. The inspections may also include testing of electrical and mechanical equipment and rigorous structural and geological assessments.
TVA says it has spent about $400 million since 2010 on dam safety. That includes current projects at Nolichucky, Boone, Pickwick and other sites.
