A gaggle of elected officials and senior government staff from Knoxville and Knox County stared up the 130 steep steps leading to the top of Norris Dam, arguably the prototype of the entire Tennessee Valley Authority system.
They happily took only a few steps up for a picture and headed back down the long hallway in the center of the massive 90-year-old concrete slab.
Like many ideas, this behind-the-scenes tour was conceived over breakfast.
TVA Community Relations Manager Bryan Johnson approached Knox County Commissioner and Knox County mayoral candidate Larsen Jay at a breakfast for the Knox Education Foundation in late July. The two discussed possible educational tours for elected officials, and Norris Dam seemed like a natural choice.
Located about 25 miles north of Knoxville, the dam offered a well-timed tour in the days leading up to National Hydropower Day on Aug. 24, a celebration of the original renewable energy source.
Erik Bodiscomassink, plant manager at Norris Dam and two other TVA hydro plants, led the officials and Knox News on the tour.
Scroll through the photos and read each caption for the full story:
TVA's 29 hydroelectric dams produce around 9% of its electricity today, and the tour was a chance for the federal utility to show off its resilient but aging public infrastructure to local power players. This is the dam's sluice gate gallery, a hallway that stretches across the inside of the dam's broad spillway. City Councilmember Amelia Parker thought it would make a great filming location for an action movie, while fellow Councilmember Lauren Rider said the space reminded her of the pipes beneath New York City where the Teenage Mutant Ninja Turtles spend their days (minus the sewer). Norris Dam is a gravity dam, meaning the sheer weight of the structure keeps it in place, and separating the officials from a 200-foot wall of Norris Lake water was between 18 and 20 feet of concrete.
Knox County Commissioner Rhonda Lee and Knox County Engineering and Public Works Director Jim Snowden stare up at hydraulic valves that control the sluice gates inside Norris Dam, named for Nebraska Sen. George Norris, who sponsored the legislation that created the nation's largest public power provider. When dam operators need to release water from the lake to the Clinch River downstream, they can open these valves to let water spill through. This is different than spilling water over the top of the dam when the lake level rises too high, a rare phenomenon that draws thousands of people to the dam to see the cascade. The Art Deco-style dam, built between 1933 and 1936, is 265 feet tall and 1,860 feet long.
Lee, left, and fellow Knox County Commissioner Kim Frazier pose for a selfie in front of Norris Dam's two generators. A 250-ton crane on the ceiling is strong enough to remove and replace the generators, which each produce 65 megawatts, enough combined power for 75,000 homes. It takes 24,000 gallons of lake water each second to turn the giant turbines. Two large penstocks, or specialized pipes, transport the water from the intake to the turbines. They are 20 feet in diameter. Every few years, dam operators close off the system to water and walk up the penstocks for inspections.
A steep staircase leads up from the sluice gate gallery to a landing near the top of the dam. Only five TVA staff members work at the dam during normal operations, Bodiscomassink said, and about 85% of their job is preventative maintenance. The dam is automated and remotely monitored, so when the staff members leave on weeknights and weekends, they can lock up the dam and leave it running. Remote system operators keep an eye on it.
Knoxville City Councilmember Amelia Park takes a picture of the dam spillway from a balcony overlooking the Clinch River. From this point, visitors can see water bubbling out from the dam as it leaves the turbines. TVA aerates the water with oxygen throughout the process to support wildlife downstream. A small dam downstream helps moderate the flow of water for wildlife and fishers. Sirens blare to let fishers know if a surge of water is coming from the dam as it churns out electricity.
Hundreds of thousands of people have visited Norris Dam over the years, whether for a tour or to walk through the visitors center . The dam does not constantly produce power, but provides support for the grid during times of high power demand. Operators must let water flow through at least 30-45 minutes every 11 hours to maintain water flow downstream.
Knox County Commissioner Larsen Jay looks at a large mural of the TVA system in the reception room at Norris Dam. The mural was originally painted in the 1950s but was later covered with a carpet-like material and left damaged. TVA staff uncovered it ahead of the dam's 80th anniversary in 2016, and specialists meticulously restored it over several months in 2018.
Check out the full gallery of Norris Dam photos from the tour
Six elected officials and three county staff members joined the tour:
- State Sen. Becky Duncan Massey, District 6
- Knox County Commissioner At-Large Larsen Jay
- Knox County Commissioner At-Large Kim Frazier
- Knox County Commissioner Rhonda Lee, 7th District
- Knoxville City Councilmember At-Large Amelia Parker
- Knoxville City Councilmember Lauren Rider, 4th District
- Knox County Mayor's Office COO Dwight Van De Vate
- Knox County Mayor's Office Constituent Services Director Mandi Benedict
- Knox County Engineering & Public Works Director Jim Snowden
Daniel Dassow is a growth and development reporter focused on technology and energy. Phone 423-637-0878. Email daniel.dassow@knoxnews.com .
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This article originally appeared on Knoxville News Sentinel: Knoxville officials (hard hats and all) tour a dam that can power 75K homes: See inside
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