Wednesday, March 30, 2022

1936 Norris Dam and 126netMW Powerhouse on Clinch River and 1798 Gristmill

Dam: (Satellite)
Gristmill: (Satellite)

This was the first dam built by the TVA.

TVATVA Virtual Tour
Construction of Norris Dam began in 1933, just a few months after the creation of TVA, and was completed in 1936. It has two generating units with a summer net dependable capacity of 126 megawatts. The reservoir area also helped form the backbone for the Tennessee state park system.
- Norris has 809 miles of shoreline and 33,840 acres of water surface. It is the largest reservoir on a tributary of the Tennessee River.
- In a year with normal rainfall, the water level in Norris Reservoir varies about 29 feet from summer to winter to provide seasonal flood storage.
- The reservoir has a flood-storage capacity of 1,113,000 acre-feet.

KnoxNews has some history about the dam. 

The project was started by the Bureau of Reclamation in 1927 to increase the efficiency of the Wilson Dam, but the TVA took over a soon after it was created. The dam started with two 50mw generators. [TennesseeEncyclopedia]
TVA posted

TVA posted
Dustin McCubbins: Norris!

0:30 video @ 0:09 (source)
Norris Dam is a symbol of American grit and engineering. 🇺🇸
The massive concrete structure is 265 feet high and stretches 1,860 feet across the Clinch River, creating a lake with 809 miles of shoreline. When completed in 1936, it helped power the Valley from the mountains of East Tennessee to the river shoals of Alabama.
Along with the other dams in our hydro fleet, Norris continues to provide reliable, low-cost renewable hydropower for the region.
Click on the link to get an up-close look inside.

[This is the only photo I saw that shows the two control gates open while the dam is spilling water.]

The TVA photo at the top of these notes shows just the upper control gates open. This shows the lower gates being used. I presume these are used to allow cooler water to enter the river.
By TVA Web Team - NorrisUploaded by bomazi, CC BY 2.0

I was trying to find details about how the lower gates work. I found some details in a video tour of the dam as a mural in the visitor center.
7:40 video tour of the dam @ 2:28
[At 0:09, this video calls Norris the flagship of TVA's system of locks and dams.
At 2:54 it labels the generators as 65mw. It takes 24,000 gallons of water to spin a turbine. That is 3200cfs.
3:04 answers another of my questions. The crest is not fixed. It has drum gates.
The video also mentions trout fishing. I've learned elsewhere that that is why they are concerned about making the river water cooler than surface lake water.
The roadway across the top was the first limited access highway in the state.]
TVA posted
Did you all wake up early to catch the lunar eclipse this morning? One of our technicians at Norris Dam snapped this fantastic photo of the blood moon on his way to work! 

TVA posted four photos with the comment: "For over 89 years, our power-producing dams like Norris Dam have helped keep the lights on, the economy humming, and the AC running!  During these hot days, we are especially thankful for our original renewable power source - hydroelectricity. "
James Torgeson shared




[A caption on the first photo in a gallery of construction photos indicates that the heavy-duty bridge was temporary. This bridge became obsolete when they finished the road across the top of the dam.]

Fort Loudoun Lock posted
Also TNhistoryForKids

TVA posted four photos with the comment: "Construction began on Norris Dam on October 1, 1933, and we wanted to show you some of the first photos taken on site. The first excavator shovel, the first concrete work, some of the first meals made on-site, and even cooking in the mess hall! "




[An article about the reporter Ernie Pyle. He was famous for reporting WWII, but he also wrote several articles explaining TVA and Norris Dam.]

TVA posted two photos with the comment: "Rain, rain, go away! Increased rainfall in the eastern portion of the region dropped 2"-4.5" on the Clinch River system in just two days. As a result, we stored water in Norris reservoir, causing the lake to rise about 10 feet, which averted around $8 million in damages to Clinton! We are now generating and sluicing at Norris to recover flood storage and return to normal operations."
Derrick Johnson: Let's hope we don't get another dry spring like last year. The early water was released to make room for the March and April rain that never came.


TNstateParks, sixth photo


Tennessee State Parks posted
Location: Norris Dam State Park
Norris Dam State Park's goal during this year's My TN State Park Fundraiser was to raise enough money to restore the Historic Rice Gristmill at the park. Over 60 people donated just over $3,000 to Norris Dam during the fundraiser, allowing the park to start the long-awaited restoration project. A portion of the funds are currently being used to replace cogs inside the gristmill. Staff will continue to post updates about the restoration on the park's Facebook page.
Photo of the Historic Rice Gristmill at Norris Dam State Park, taken by ©Tennessee Photographs. See more images from Tennessee Photographs at


There is also an historic threshing barn (and "event space") and museum near the dam.
TNstatparts, p1

TNstatparts, p2

The TVA moved the mill from Lost Creek to Clear Creek. [TNhomeAndFarm]

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