Chattanooga Times Free Press

BOONE DAM REPAIRS TO COST TVA $450 MILLION

Over the next five years, TVA expects to spend another $200 million on safety inspection­s and repairs on its dams across its seen-state service region

- BY DAVE FLESSNER STAFF WRITER

The Tennessee Valley Authority has nearly doubled what it initially expected to spend to shore up seepage problems at its 65-year-old Boone Dam on the South Fork Holston River in northeast Tennessee.

The 160-foot-high Boone Dam, which was started in the 1940s and completed in 1952, requires the installati­on of a composite seepage barrier wall to secure the dam, which is used for both flood control and hydroelect­ric power generation.

TVA started investigat­ing problems at the dam in October 2014 and launched constructi­on of the composite seepage barrier in July 2015.

“As we got farther into the work there, we learned more about what is actually happening and that provided us the data to make a more robust estimate,” TVA President Bill Johnson told analysts during a conference call last week. “As design and constructi­on plans are finalized for this ongoing, multiyear project, the estimated costs and

“As we got farther into the work there, we learned more about what is actually happening and that provided us the data to make a more robust estimate.”

— TVA PRESIDENT BILL JOHNSON

duration are being refined and we expect to invest in the range of $450 million to secure the Boone project completion in 2022.”

The repair project is one of the most expensive ever at a TVA dam, but Johnson said the seepage problem at the Boone dam does not indicate any systemic or widespread problems across TVA’s network of 49 dams on the Tennessee River and its tributarie­s.

“These dams were built in different times, on different geologies and with different constructi­on methods,” Johnson said. “Some are earthen, some are concrete and some are both. There is no systematic extent of condition here that would make us concerned about other dams.”

Over the next five years, TVA expects to spend another $200 million on safety inspection­s and repairs on its dams across its seven-state service region.

“When you are looking at all of the 49 dams and their embankment­s, occasional­ly we will find these challenges,” TVA spokesman Jim Hopson said. “These are all unique and all different, but we repair them as we find them. The cost of the Boone Dam repairs has gone up, but this is the first real estimate of what it would cost.”

Johnson said TVA’s ongoing dam inspection program has uncovered problems at a couple of other dams, including some being addressed at the 79-year-old Pickwick Dam in southwest Tennessee. But the costs of repairing the other dams will be significan­tly less, Johnson said.

Boone Dam Project Manager Sam Vinson said in a recent TVA report that a lot of progress has been made during the past year and a half of work. About 800 holes have been drilled and grouted in the earthen embankment and will provide important data for the remainder of the project and for the final design.

“Like similar aging facilities we have relied upon for decades for hydroelect­ric production and flood control, Boone is an important part of the infrastruc­ture our country relies upon every day,” the TVA CEO said in his quarterly earnings report last week. “These assets require regular maintenanc­e and repairs to stay at peak performanc­e and TVA is committed to maintainin­g the dams that have been entrusted to us.”

Contact Dave Flessner at dflessner@ timesfreep­ress.com or at 423-757-6340.

 ?? CONTRIBUTE­D PHOTO BY TVA ?? TVA is using about 250,000 tons of stone from a local quarry near Tri-Cities Airport to add stability to the upstream side of the earthen embankment at the Boone Dam near Kingsport, Tenn.
CONTRIBUTE­D PHOTO BY TVA TVA is using about 250,000 tons of stone from a local quarry near Tri-Cities Airport to add stability to the upstream side of the earthen embankment at the Boone Dam near Kingsport, Tenn.

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