South Holston Dam is an earthen dam in such sharp contrast to the green valleys and hills approaching it. That doesn't mean that I am against such structures or their use. Still, it does speak strongly of human ingenuity, engineering, and dominion over nature. The straight lines of the naked, gray limestone boulder terraces used to maintain the dam are not pretty, but they are functional.
Looking beyond that stark functionality, you see a beautiful lake and surrounding mountains. Given its depth and source water, I assume it is probably one of the coolest TVA lakes in the system. (1)
I well imagine that you could not drive across this dam after 911 as you can now. If you look closely, you will see a vehicle parked on the dam while someone got out to take pictures.
These dams are similarly sloped on the lake side under water in order to hold back the multiple tons of pressure per square foot on the bottom of the dam. (2)
Picnic Area
Iron Mountain commands the far side of the lake. There must be a good view on the Appalachian Trail up there. I guess I will just have to go find it.
The structure at left is a standpipe for the generators. The dam was constructed in just over 4 years during a 9-year period, having been delayed by WWII.
There are a half dozen types of turbine blades for hydroelectric dams. (3) The two most common ones for large installations are the Kaplan, which resembles the propeller on a ship, and the Francis, also called a squirrel cage, which resembles the enclosed fans by the same name. I could not imagine why one would wear out and be displayed as we see here. But in my first year of teaching, I secured a tour for my students a tour of the powerhouse and control room of a nearby dam. Quizzing the controller about what he did, I was informed that it took quite a bit of skill to bring a generator online. Before electronics and still on many dams where electronics have not been retrofitted, the operator must manually synchronize the generator with the electrical grid. There is a powerful electrical counterforce to the momentum of the rotating generator called counter electromotive force or counter emf. If not synched correctly, the counter emf can produce such a jerk on the turbine as to detune it. I should have pursued exactly what that means, but I think that it means either that the turbine is warped or the bearings compressed so that the turbine then wabbles like an unbalanced tire eventually destroying itself and surroundings. Sorry about that. I went all science geek nerdy there for a minute.
Another byproduct of electrical generation is very cold, oxygen low discharge water. That makes for a sterile river many miles downstream. TVA came up with an ingenious solution that was implemented below this dam. At two points on the river on either side of an island, they built these grid waterfalls. Their shape greatly increases the surface area of the falling water which oxygenates the water.
Talking to one of the fishermen below this structure, he told me that 14 miles of this section of the South Holston River is considered to be one of the best fly-fishing rivers in the country.
Pedestrian bridge across to the island and walking trails
Technology and man's needs along with nature can co-exist. It is a matter of proper stewardship. I believe that this is what God intended in Genesis 1:26-30 and 2:15, not restricting all of creation to preserves nor trashing it for mere functionality or money. So much of life is a balancing act. I could go all pedantic on this score as well, but I will spare you.
It is a peaceful, cool, and inviting scene. Only God could make it; we must utilize it with care.
1. Exclude Wilbur Lake below Watauga Lake which is a constant 42 degrees all year round because its waters flow off of the bottom of Watauga Lake.
3. Types of Hydropower Turbines | Department of Energy
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