Photo courtesy of U.S. Army Corps of Engineers
The U.S. Army Corps of Engineers Nashville District constructs a new navigation lock Feb. 20, 2024. The dam is a Tennessee Valley Authority project. The Nashville District is managing the Chickamauga Lock Replacement Project.
The new and bigger lock being built at the Chickamauga Dam in Chattanooga is designed to expedite the flow of barge traffic on the Tennessee River but building the replacement chamber has proven to be anything but expeditious for the U.S. Army Corps of Engineers (USACE), the facility's operator.
The Chattanooga Times Free Press reported May 11 that after more than two decades of development, construction and cost overruns that have more than tripled the original projected cost, the USACE is preparing to award what it said will be the last major contract for what has become Chattanooga's longest construction project.
The largest congressional earmark in 2024 was added to the federal budget to pay for the final $237 million of work to build the upstream approach walls and finish other elements in and around the new and bigger lock.
"This lock, as part of the nation's inland waterway system, is critical for providing safe, reliable, efficient and environmentally sustainable waterborne transportation for the movement of commercial goods for national security needs and for recreation," Lt. Col. Robert Green, commander of USACE's Nashville District, noted in a news release. "There is a need to reinvest in our aging inland navigation infrastructure, and we are thankful to our elected officials and partners for the strong push to fund this final milestone."
Joseph Cotton, a captain with the USACE, and project manager of the new Chickamauga lock, told the Chattanooga news source that nine construction companies have expressed interest in bidding on the contract to complete the lock.
He expects to begin receiving proposals in June before awarding a contract for the final approach wall and other work later this year in time to have the new lock built by 2026.
However, the entire project, including the closing of the existing, smaller lock and reclaiming the property around the dam with the addition of a new section of the Tennessee riverwalk, is not expected to be finished until 2029, Cotton said.
"During construction, [the] safety of our contractors, followed by mitigating impacts to navigation, are our top priorities," he noted, adding, "Throughout this contract, the old lock will remain in operation until the new lock is open for public use, so no outages are expected."
Delays, Cost Overruns Have Plagued Construction
Several factors have delayed the lock's construction, putting it years behind to open it for river traffic.
The USACE previously projected the new Chickamauga lock had enough funding and would likely be in operation by now. President Biden did not request additional funding for the lock in 2023, but the federal agency told the Chattanooga newspaper that extra costs caused by COVID-19, material inflation, tight labor markets and supply delivery problems boosted the total cost of the project from the previous $757 million completion cost to the new total cost of $954.4 million.
Even with the higher price tag for the lock, Cotton said it will deliver at least as much economic value for the region as what it cost to build the lock.
Oakland, Calif.-based Shimmick Construction is the prime contractor behind the new lock chamber below the Chickamauga Dam. When the company was unable to complete the work within the original timetable, Shimmick asked the USACE for another $96.3 million and 590 days to finish the job.
According to the Times Free Press, the contractor has had as many as 450 workers on site excavating the riverbed and building the downstream approach walls with concrete transported to the new lock chamber via a conveyor belt from Shimmick's cement batch plant along Access Road.
The effort also is aided by two of the biggest construction cranes anywhere in the country, the news source added.
At the same time, on the upstream side of the dam, C. J. Mahan Construction, from Grove City, Ohio, is working to build a new approach wall above the barrier.
The Tennessee Valley Authority (TVA), which was created in 1933 to harness the power and navigation of the Tennessee River, originally built the Chickamauga Dam and Lock using nearby rock aggregate that has since developed structural problems, forcing prolonged maintenance outages and expensive repairs to the lock.
The dam remains a TVA project today, but the lock is maintained and operated by the USACE and is funded with both congressional appropriations and proceeds from diesel taxes paid by river barges on America's inland waterways.
New Lock to Keep River Commerce Flowing
Congress first authorized the current lock project in 2003 after the USACE requested a larger, 110-ft.-by-600-ft. replacement lock to allow up to nine barges at a time to pass through the Chickamauga Dam. By contrast, the existing 60-ft.-by-360-ft. lock allows only one barge through at a time.
"The bigger lock at Chickamauga will align with the size of other locks downstream on the Tennessee River and help the shipment of many goods along this important inland waterway," Tracy Zea, president and CEO of the Waterways Council Inc., said in a telephone interview with the Times Free Press.
U.S. Representative Chuck Fleischmann, R-Tenn. 3rd District, and chair of the energy and water appropriations panel that helps fund the USACE, pushed for the extra $237 million to finish the lock after he was approached last year by Corps' officials who said more funds were needed.
The USACE had not previously requested such funding, but after learning of the latest problems with the project, Fleischmann used congressional earmarks to include the work in his overall energy and water appropriations package.
Fleischmann told the Times Free Press that he was surprised by the amount of extra funding needed to finish building the lock but recognized the need to maintain river navigation on the 318 mi. of navigable river upstream from Chattanooga and to ensure that goods and products can be delivered to major industrial users as well as for national security and energy needs at the Oak Ridge National Laboratory and the Watts Bar Nuclear Plant in East Tennessee.
About 1 million tons of freight a year is moved through the Chickamauga lock, and a modern chamber is projected to reduce commercial transit times by 80 percent. The facility also is the most active lock on the Tennessee River for recreational vessels, with more than 3,500 vessel lockages annually.
The USACE also projects the lock will help keep up to 150,000 trucks off nearby Interstate 75.
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