Project on Douglas expected to last through June
CREDIT TO: Steve Marion, The Standard Banner, February 27, 2025
It took nature a few days to flood Douglas Lake with a mile-square flotsam field. It’s taking man more than half a year to clean up the mess.
TVA and state, federal, and local partners working on the massive project to clean up debris in the wake of Hurricane Helene offered a progress update this week. The partners hosted a public meeting at Jefferson County High School and gave reporters a first-hand look at the shoreline cleanup activity.
TVA officials said that both land and water-based methods are being used to clear vegetative debris and move it to burn areas. On the shore with hydraulic track-hoes and other equipment, and from the water with hydraulic equipment mounted to barges, contractors gathered vegetative debris and moved it to burn areas. In both instances, the first step is the removal of household and other waste, which is trucked separately to a landfill.
“When we first got the mission assignment from FEMA, the maximum elevation to which we could remove debris was at 990,” said Scott Turnbow, TVA Vice President of Civil Projects and Equipment Support Services, “but we’ve been able to increase that zone to 1002. That’s an extra 12 feet [of debris] that we’ll actually be able to remove.
“Then, as we get all that debris cleaned up, we’ll move toward the cliffside. That will happen sometime around March, April, May. When that happens, we’ll have to start raising the water level to be able to reach those cliffsides.”
Contractors have 36 barges in the water moving debris. Ninety-nine percent of the debris is vegetative, but local residents say they have also seen household items like refrigerators and even parts of prefabricated sheds on the shore line. Workers have picked up a large number of vehicle tires.
Meanwhile, TVA has begun an underwater survey to identify any potential concerns due to sunken debris. The Tennessee Department of Environment and Conservation (TDEC) continues to monitor water quality. TDEC issued a “no contact” advisory for Douglas waters after Helene but lifted the advisory on January 15 after water testing.
Other agencies at work on the cleanup project include the Tennessee Department of Military, the Tennessee Department of Labor & Workforce Development, the Environmental Protection Agency, and Tennessee Emergency Management.
The Shady Grove access area remains temporarily closed to provide a staging area for heavy equipment. The site includes a crane used to place barges into the lake.
Significant rainfall in February (just under four inches in Dumplin Valley but more upstream) recently pushed Douglas Lake more than 10 feet above its expected level for this time of year. The lake was at 970.46 feet above last week but had dropped to 965.21 yesterday. TVA officials said the rising waters have not hampered cleanup efforts.
‘We had to act’
Before the storm made landfall in Florida at the end of September, TEMA knew it would affect the state, said Director Patrick Sheehan. That appeared likely from the very first “spaghetti models” of the storm’s likely path.
Early on, it appeared that hurricane-force winds and heavy rain were headed for Middle Tennessee.
“As it turned out, that track stayed just a little farther east and deposited just incredible amounts of rainfall — 40 inches of rain in some areas of North Carolina in the headwaters of the Nolichucky and the French Broad,” said Sheehan.
Technicians at the National Oceanic and Atmospheric Administration (NOAA) estimate that Helene, which stuck the Gulf Coast September 26 as a Category 4 hurricane, combined with a less forceful system that preceded it to produce over 40 trillion gallons of rain in the Southeast (as much as is contained in Lake Tahoe), far greater than any system in the past 25 years, perhaps longer.
Hurricanes often dissipate upon striking land, but Helene accelerated, ripping inland and striking the Appalachian Mountains, where most of the rain was dumped, creating a massive run-off unlike anything seen in the past century.
Creeks and rivers changed course. Areas that had never flooded before flooded. The torrent ran through Asheville, North Carolina, and many small towns in the state. It reached Newport in East Tennessee before Douglas Lake caught it on this side.
It’s currently estimated that more than 230 people died in the storm, and damages are estimated at more than $200 billion. Interstates 40 and 26 were impassable in many locations, and more than 400 roads in North Carolina were seriously damaged. Five bridges were destroyed in Tennessee, and 14 were closed.
Douglas Lake, in the midst of its late summer drawdown, was languishing at 978 feet above sea level during the final full week of September. Helene punched it up nearly 21 feet to just over 999. That’s a body of water 44 square miles in size, more than a mile wide in places.
TVA opened the floodgates on Douglas on September 28. Outflow averaged about 24,000 cubic feet per second or nearly a quarter of the amount of water that flows over Niagara Falls during its peak season. That outflow level (15.5 billion gallons per day) translates to more than 100 billion gallons of water traveling through the dam.
Running the numbers in the other direction and considering that the current outflow drops the lake by about a foot each day, Helene appears to have poured 3.2 trillion gallons of water into Douglas Lake — enough to fill almost a half million Olympic size swimming pools.
Debris carried by the storm water tangled into a mile-square mat that appeared to be moving about a mile per day and had the potential to threaten operations at Douglas Dam.
“It became apparent quickly that we had to act,” said Scott Brooks of Tennessee Valley Authority.
TVA boats deployed a 4,000-foot inflatable boom anchored on each side of the reservoir in an attempt to block the debris field’s march toward the dam. Made of a synthetic material like a raft, the boom included netting that extended another 18 inches below the surface.
“We had to act quickly or the debris could have caused mechanical problems at the dam — or, since the dam [was] spilling — reached the Tennessee River and created problems for navigation and water supply intakes,” Brooks said.
The boom, located at Mile 11 at Swanns Shoals upriver from the Town of Dandridge, was one of the biggest such efforts TVA has ever undertaken. The boom was removed November 27, but could be redeployed in the event of an emergency.
Work continues
Created in 1943, Douglas Lake has 555 miles of shoreline along its twists, turns, and bays — and a map profile that some have compared to a Chinese dragon. Shores on the south side of the lake are often steep, sometimes cliff-like, while the banks are a little more gentle on the north. As the water level dropped, debris was stranded along all the fringes of the dragon. Removing the debris will take a couple of passes in some areas, using the rising water as a tool.
Contractors are doing the work by zones, which correspond to point numbers on the lake. Plans call for Zones 1-10 to be done by the end of April, while 11-20 should be done by the end of May. That will leave four zones, all of which should be complete by June 23, according to the latest estimate.
Man changed the river forever with construction of the dams, but Douglas Lake itself won’t be around forever. A TVA study estimates that the reservoir will fill with silt to its minimum operating level less than 100 years from now, and the lake will be a silt flat to the top of the dam 12 centuries after its construction. Storms like Helene could only hasten the coming of that situation.
