Rising Waters and Anticipation
TVA has big plans for Boone Dam next month. On March 15, TVA’s River Forecasting Center will start incrementally raising the water level by about two feet per week. By mid-summer, the lake is expected to be at or near the usual summer pool level as it existed prior to 2014. These fluctuations mark the beginning of a period of testing and performance to be completed prior to fully returning the lake to normal operations in July 2022.
Boone lake levels have been lowered since the fall of 2014 when a sinkhole was discovered at the base of Boone Dam. Fishing and boating enthusiasts, homeowners with docks, marina operators with facilities on the water, and other area residents have been impacted by the restoration work and resulting low lake levels, but a return to normalcy is now on the horizon.
“I hope the increase means residents can start getting excited about ultimately having their lake back,” said Chris Saucier, the project’s technical director. “We’re confident the lake will be back, and that the dam will be safer than it was before. For the short term, it means people, and especially boaters, need to be vigilant of water levels as they rise.”
According to Sam Vinson, project manager, for residents nearby, one of the biggest changes is that crews will no longer be working through the night. “This means the potential impacts brought on by noise and light pollution will be resolved soon,” he said.
A Multi-Year Repair
The sinkhole at Boone that was discovered in October 2014 was evidence of a dangerous process called “internal erosion” by which seeping water is able to remove soil from the embankment dam and transport it to the riverbank below, to be carried away. This spurred a multi-year repair effort that required the lake’s water surface to be lowered 1,350 to 1,355 feet above sea level.
An underground cutoff wall was recently installed to prevent erosion and seepage along the dam’s earthen embankment, and is currently being tested and inspected as the water levels incrementally rise – known as raise and holds. This practice helps the team evaluate the wall’s performance and ensures safety and reliability of the repair, as well as provides valuable baseline data regarding changes in the site’s groundwater flow patterns that may be created by the repair.
An Eye Toward Safety
“There are two things we’ve tried to consistently communicate throughout the project – we want to restore the usual lake operations quickly, but we will place the highest priority on the safety of employees and the public as we do so,” said Saucier. “Those two factors things have guided our approach from the very beginning.”
The next steps in the Boone project include the construction of a flood wall as part of the embankment’s crest restoration and site restoration of the public areas, putting the beach and restrooms back. “These activities will continue until the summer of 2022, including during the period of the proposed lake level fluctuations,” said Vinson.
TVA has stayed within budget for the repair project and the five-to-seven-year time frame it initially laid out for the work.
Daily progress updates can be found here.