Boone Dam Seepage Information
In October 2014, TVA discovered a sinkhole near the base of Boone Dam. About a week later, TVA Dam Safety inspectors identified seepage of sediment and water just downstream. Ongoing investigations have thus far been unable to determine the source of the seepage. As a safety measure, TVA accelerated winter drawdown and lowered the level of the Boone Reservoir to about 10 feet below normal winter pool elevations. In February 2015, TVA announced that the reservoir level will be held at or below that reduced level for an undetermined period of time.
Action Being Taken
TVA is continuing to monitor the dam closely, investigate the seepage, conduct preliminary site work, and work to determine the best permanent repair option. The work has been reviewed by an independent review board of national dam safety experts. Recent work at Boone Dam includes:
- Installation of advanced instrumentation
- Drilling core samples to study the condition of the earthen embankment
- Use of sonar, radar and lasers to monitor underground and underwater conditions
- Placing a temporary filter along the river bank near Unit 1 to help control soil erosion and capture sediment
- Collaboration between TVA Dam Safety experts and industry experts from around the world to analyze the situation thoroughly
Boone Dam Briefing
The Next Step
Work is anticipated to begin this spring on using grout injection to improve conditions underneath the earthen embankment. This interim step is only part of the process. TVA is still analyzing the situation to determine the best permanent repair options. Once the decision is made on how best to proceed with the permanent repairs, more will be known about the duration and impacts the project will have on the reservoir.
Dam Safety at TVA
Monitoring and inspection is an integral part of our Dam Safety Program. We are continuously monitoring Boone Dam while investigating the seepage there. TVA has a long history of operating our hydroelectric dams across the Valley, and they have performed well. The safety of our workers and the public continues to be our overriding priority.