1913-1972 Nolichucky Dam on Nolichucky River south of Greeneville, TN

(Satellite)

An aftermath of Hurricane Helene in Sep 2024.

"On September 27 at about 11:30 p.m. ET, out of an abundance of caution, TVA issued a Condition Red alert, which meant that a breach was imminent." As of 9am Sep 28, Local Emergency Management Agencies had ordered evacuations. As of 4pm, TVA rescinded the Condition Red alert because water levels were receding at about 1 foot an hour. "The Nolichucky Dam peak water elevation hit 1266.0’, which is 9.5 feet over the record elevation of 1256.5’ set on November 6, 1977. The 1.3 million gallons per second [174kcfs] flow rate at 11 p.m. on September 27, more than doubles the flow rate of 613,000 gallons per second [82kcfs] from the previous regulated release in 1977." [TVA_news] To put 174kcfs in perspective, I think the flow rate that wiped out the spillway of the Oroville Dam was about 100kcfs. A Knoxville News Sentinel summary said the "flow reached nearly twice Niagara Falls." But the article was behind a paywall.

0:19 video
This is the Nolichucky Dam in Greene County in East TN. TVA says the dam is still intact, but they continue to assess the situation. 🙏

I think this is the TVA video that was the source for the above post.

 

TVA posted

⚠️ Out of an abundance of caution, we have issued a Condition Yellow for Nolichucky Dam in Greene Co., TN.

A Condition Yellow indicates that the dam is approaching its threshold to withstand excessive floodwater, necessitating immediate action. The dam structure has not failed.

Local county emergency management officials are coordinating evacuations as appropriate.

Extreme rainfall from the remnants of Hurricane Helene is causing record river levels.

Facebook reel

 

I noticed that they are not letting traffic cross the bridge.

wjhl

This is a normal flow over the dam.

Street View, Mar 2023

This is the lowest flow I could find with Street View.

Street View, Nov 2023

This was the highest flow I could find with Street View.

Street View, Jul 2013

TVA
"The dam is 94 feet [29m] high and 482 feet [147m] long."
The hydroelectric equipment was removed in 1972 because the reservoir filled with sediment. I could not determine what the capacity was when it was built. It was built to generate electricity.

Normally, I can find a dam on a river by looking for a skinny line next to a fat line. But in this case the river is as wide below the dam as it is above the dam. That means the river is in a steep canyon.

Satellite

TVA posted five photos with the comment: "We continue to focus on the safety of Nolichucky Dam in Greene Co., TN. Heavy machinery is onsite, placing large rocks to stabilize the area the flood waters scoured away. We are also removing the old powerhouse because of the damage caused by flood waters - the facility hasn't been in service since 1972.
Dam Safety engineers and construction teams are conducting a thorough review of the area and will make any necessary repairs to the dam."

Brett Wanamaker shared

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Digitally zoomed to Facebook resolution

Oct 14, 2024:

TVA posted
Our Dam Safety team will perform a downstream inspection of the Nolichucky Dam in Greene County, TN, on Wednesday, Oct. 16, and if more time is needed, finish the work on Thursday, Oct. 17. The dam's small spillway gate will be opened on Tuesday to lower the reservoir so we can perform the inspection with no water flowing over the main spillway. The dam remains stable and secure.
Ernie Berry: It did not break. A lot of people reported it broke because there was so much water moving downstream. It was reported that 325+ million gallons flowed into Douglas with around 275 million coming from the noli. In places the noli was 1/2-3/4 mile wide and 20-30’ above normal flood height. No one alive today had ever seen the noli like it was that day.

TVA posted five photos with the comment: "Our dam safety experts conducted a thorough inspection of the Nolichucky Dam this week using high-tech equipment, including underwater remote-controlled cameras, LiDar laser measuring equipment, and aerial drones. Engineers will continue to evaluate the information, but the initial inspection determined no major damage to the dam structure. Construction crews continue to repair the dam’s right abutment, which was scoured by the historic flooding from #Helene."

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