Drilling and grouting work shown here is among the recent work completed at Boone Dam, TVA’s largest dam safety project
No matter how big or small, TVA considers all of its dams vital components of the Tennessee River and its tributaries. And there is no better time to recognize that than on National Dam Safety Awareness Day.
National Dam Safety Awareness Day is observed each May 31 to recognize the importance of dam safety. The date marks the worst dam failure disaster in U.S. history: the 1889 South Fork Dam failure in Johnstown, Pennsylvania, which claimed more than 2,200 lives.
This week, TVA dams were critical in helping avert and control flooding from Subtropical Storm Alberto across the Tennessee Valley. They did the same to manage record rainfall in parts of the Valley in February.
“TVA’s Dam Safety team works on dams of all shapes and sizes to ensure they work as they are designed to, protecting people, property and communities across the Tennessee Valley,” said Jennifer Dodd, general manager of Dam Safety. “No matter how big or small, all our dams are important. Keeping them operating as designed and keeping downstream communities safe are our top priorities.”
TVA’s current smaller dam projects include:
Clear Creek – TVA began construction this month at its Clear Creek Dam in Bristol, Virginia, at the dam’s stilling basin to provide scour protection and prevent deterioration of existing rip rap shoreline downstream. The project also will install improvements to accommodate better monitoring of the drainage infrastructure beneath the dam.
Little Bear Creek – TVA has completed the second phase of investigation of seepage at Little Bear Creek Dam. After discovering seepage last year in the spillway, dam safety investigators confirmed that the spillway subgrade has not been degraded by seepage and also identified potential seepage paths within the dam’s bedrock foundation. The reservoir is expected to operate at normal summer pool as TVA continues to monitor and assess the dam.
Chatuge – TVA Dam Safety and TVA Police have started an initiative to install video cameras at select dams which will improve existing surveillance capabilities and increase warning times in the case of a dam safety emergency. The initiative will start with Chatuge Dam, where video and thermal cameras will be installed to allow observation during the daytime and nighttime hours. Construction is scheduled for the summer of 2018 with completion expected by September 30, 2018.
TVA’s larger-scale dam projects currently underway or recently completed include:
Kentucky – TVA and contractors began work this month on a berm made of sand, gravel, and riprap on the downstream slope of the Kentucky Dam embankment. The completed berm will stand approximately 400-feet-long and 10-feet-high. Work on this project is scheduled to be completed in July. The berm project is designed to prevent a dam failure in the event of a major earthquake.
Fort Loudoun – TVA in April completed a new 7-foot high concrete flood wall at TVA’s Fort Loudoun Dam, the last in a series of major construction projects at five TVA dams to protect Watts Bar and Sequoyah nuclear plants in a worst-case flood scenario. The wall is 1,200 feet long, crests at 837 feet above sea level, and is four feet higher than the old wall it replaces. The Fort Loudoun work also included construction of a 1,400-foot long Roller Compacted Concrete (RCC) section of the dam’s south embankment and post-tension anchors and steel bar reinforcement of other parts of the dam.
Pickwick Landing – TVA is upgrading the upstream and downstream sides of the south embankment of Pickwick Landing Dam with berms in select locations. The work started in late 2017 and will end in late 2021 and is designed to prevent damage to the embankment in the event of a large seismic event. TVA also has installed an early warning system to provide more rapid notification to downstream residents in the event of a major earthquake.
Boone – Construction of the composite seepage barrier at Boone Dam is moving forward on schedule for completion by 2022 within the initial estimated 5-7 year timeframe. TVA this month completed construction of upstream and downstream rock berms consisting of 235,000 tons of material,l and is currently in procurement for the cutoff wall contractor, which is expected to be ready to start work this fall. The project remains on schedule, and TVA continues to monitor data to make any additional adjustments to ensure the safety of the public and quality of the repair.
“Dams provide many benefits, including water supply, flood control, recreation, and hydropower,” Dodd said. “But they also have risks. National Dam Safety Awareness Day is a good time to take steps to reduce risk if you live, work, or recreate near dams.”
Those safety steps include the following:
- Know your risk: contact your local emergency management agency or state dam safety official.
- Know your role: have an emergency preparedness plan for you and your family, and practice it.
- Know your evacuation route: talk to neighbors about dam safety.
Also, when you are around dams:
- Be aware of the potential dangers caused by changing flows, and stay clear of waters near stations and dams.
- Always stay a safe distance outside of warning signs, buoys, and barriers.
- Obey all warning signs near dams, and wear a life jacket.
Click here to learn more about National Dam Safety Awareness Day.