Tailwater and water release scheduling.... TVA

[Big Bad Wulff]

Slight rant here. But I'm really looking for some answers and wanting to learn if there is something to learn.


If there is anyone that knows why and when they release water, please let me know. Ok I do know they release water if the pool gets too high or they need to generate some electrons for power use. Iknow they release to help cool the stream down in the summer so the trout don't die.

But why on Earth does Caney Fork(Center Hill dam) release water from 8-10am every day this time of year!? Can't they do that in the middle of the night and allow us to fish during the day ininterrupted when power use isn't in that great of demand(67 degrees yesterday) and the fact water pool is a little low as it is now?
I know at Norfork in Arkansas they run from about 3-5 am mostly when demand is low. Granted Norfork is only about 4 miles long.

Where I fish on the Caney is about 3 hours downstream from the dam so I can fish until about 11 am before the water rises and then have to go closer to the dam(with everyone else!) where the water is now receeding. During low-light-hour days the water doesn't have time to receed back down before it gets dark at my usual starting point(3hrs downstream).

Anyone know why they release water the way they do at Center Hill?
Or is it simply no one wants to work the dam in the wee hrs of the night?

[garyj147]

Big Bad Wulff,

First of all, please allow me to inform you that the Center Hill Dam project is NOT a TVA project; it was built and is operated by the U.S. Army Corps of Engineers. Their headquarters is in Nashville, TN (for the district in which Center Hill lies). You can find their office phone number in the Nashville phone book or online.

Next, an observation on some of the "whys" behind generation schedules. As a fisheries biologist who works for TVA, I am peripherally qualified to answer some of these questions. First, as to the "why" many projects generate between 8-10 a.m. What time do most folks go to work? How many industries and businesses start up between 8 and 10 a.m. across the country? Each of these start-ups require increased power supply for lights, machinery and equipment. It is not efficient to try to generate this power hours earlier, then run it around a grid until the demand increases. If this was the way the power system operated, your home utility bill would be even higher than it is now, due to increased costs of producing power.

Second, why does an outfit like TVA use water turbines instead of merely operating the coal-fired and nuclear plants we have? Arguably, hydropower is still the cheapest, cleanest source of electrical power you can get in mass quantities. TVA hydropower supplies about 10% of our total power demand in the Valley. Utilization of hydropower to its fullest potential helps keep customer's power bills lower.

You have identifed some other reasons for running turbines as frequently as they are operated. In the Caney Fork, the greater use of turbine releases has resulted in greater survival of trout and their food organisms by keeping more of the river bottom permanently wetted. Fish and aquatic insects do not survive well when the bottom of the river is dry. Historically, the lack of permanently wetted riverbeds has had a dramatic impact on trout and aquatic insects in our part of the country. TVA has spent millions of dollars to construct re-regulating weirs below South Holston and Norris Dams to provide more water flow to increase trout and insect habitat. These efforts have paid off handsomely!

Next, you indirectly addressed flood control. Turbines have been used in many projects to pass along flood waters, in cases where spill gates were determined to not be necessary to allow this water passage. Flood control was, and continues to be, a primary reason for the construction and operation of dams, especially here in the Southeast.

I hope these points help you understand the "whys" of your question.

Gary

[Big Bad Wulff]

Thank you Gary. That all makes perfect sense.

[DShock]

Big Bad Wulff,

First of all, please allow me to inform you that the Center Hill Dam project is NOT a TVA project; it was built and is operated by the U.S. Army Corps of Engineers. Their headquarters is in Nashville, TN (for the district in which Center Hill lies). You can find their office phone number in the Nashville phone book or online.

Next, an observation on some of the "whys" behind generation schedules. As a fisheries biologist who works for TVA, I am peripherally qualified to answer some of these questions. First, as to the "why" many projects generate between 8-10 a.m. What time do most folks go to work? How many industries and businesses start up between 8 and 10 a.m. across the country? Each of these start-ups require increased power supply for lights, machinery and equipment. It is not efficient to try to generate this power hours earlier, then run it around a grid until the demand increases. If this was the way the power system operated, your home utility bill would be even higher than it is now, due to increased costs of producing power.

Second, why does an outfit like TVA use water turbines instead of merely operating the coal-fired and nuclear plants we have? Arguably, hydropower is still the cheapest, cleanest source of electrical power you can get in mass quantities. TVA hydropower supplies about 10% of our total power demand in the Valley. Utilization of hydropower to its fullest potential helps keep customer's power bills lower.

You have identifed some other reasons for running turbines as frequently as they are operated. In the Caney Fork, the greater use of turbine releases has resulted in greater survival of trout and their food organisms by keeping more of the river bottom permanently wetted. Fish and aquatic insects do not survive well when the bottom of the river is dry. Historically, the lack of permanently wetted riverbeds has had a dramatic impact on trout and aquatic insects in our part of the country. TVA has spent millions of dollars to construct re-regulating weirs below South Holston and Norris Dams to provide more water flow to increase trout and insect habitat. These efforts have paid off handsomely!

Next, you indirectly addressed flood control. Turbines have been used in many projects to pass along flood waters, in cases where spill gates were determined to not be necessary to allow this water passage. Flood control was, and continues to be, a primary reason for the construction and operation of dams, especially here in the Southeast.

I hope these points help you understand the "whys" of your question.

Gary

Gary,
Thanks for the great post!
Doug

[WarrenP]

This is just another reason why FAOL is such a great web site and why it is so successful where other sites fail and disappear. FAOL is about sharing and helping. There is no way we could ever thank JC and LF enough for this great web site. I know it is my "life blood" and I am not sure I could get through the day without it.

I hope everyone has a Merry Christmas and a very happy and safe New Year...