Strange flow numbers and flow in WT creek

[polo-dog]

I went down to my dock at about 7:40 tonight to see if I could catch some crappie and the bite seemed to be really off. It was also strange in that the flow seemed to be into the creek rather than out from the creek. This does happen from time to time but at about 8pm the flow switched directions and became very brisk out of the creek. So fast was the flow that I don't think that I remember it being that fast when the water was at summer pool before. I just looked at the flow numbers from Chickamauga and Watts Bar and they show that the flow markedly decreased from Chickamauga but stayed about the same from Watts Bar. In my thinking I would have expected that the flow would have been decreased a little after 8pm rather than markedly increased. Sometimes I really wonder if the flow info is accurate but maybe I'm missing something here. Maybe someone can explain it to me. Thanks.

 

[Fishin' Junkie]

Interesting... Did you try fishing after you noticed the change in direction?

 

[polo-dog]

Right when the flow changed I started catching fish. The flow slowly changed from slowly out of the creek to very brisk out of the creek. I didn't catch any fish before the change in the flow, however I also decided at just about that time that I would try DK's "palsey twitch" too. I'm not sure if it was the twitch or the switch(of current) that started the fish biting but there was a definite change in activity. When the flow became very brisk I didn't catch any more fish but I had also snagged on a branch in my brush pile and pulled it all the way to the dock and threw it back on top of the pile and I would expect that the branch falling on top of the pile stopped the bite rather than the current. I ended up catching about a dozen crappie off the pile and all but two were keepers. That was good to see as most of the fish that I caught this morning were non-keepers. The count was the same as this morning though, right at 18. I tried shallower but didn't get a bite. Sometimes you can catch a couple suspended over the pile at about a 10 count but not today.

 

[Guest]

Don't forgot to add in the Hiwassee/Ocoee flow and/or the nuke (not sure how much water it uses).

 

[drumking]

It's that "palsy" twitch that gets'm every time, Polo. emoBigsmile

 

[rsimms]

Polo... I've been pondering this issue. (Back and forth Wolftever water flow). First, I don't believe there is anyone, especially me, who fully understands all the water flow dynamics on the Tennessee River. There are simply too many variables.

However, this is my THEORY on what is happening in Wolftever (and probably other creeks). I believe when TVA cranks up heavy generation... for instance going almost immediately from 10,000 cfs to 45,000 cfs, there is an initial "rush" of downstream flow. But after a while that "rush" equalizes out causing the apparent "backflow."

Here's my analogy... consider a drain in your sink that might be partially stopped up (a TVA Dam). When you first turn on the water faucet (crank up the generators) the water initially flows quickly and easily down the drain. However after a while, and depending upon how hard you turn on the faucet, the flow backs up or at least equalizes. The flow down the drain (Wolftever Creek) slows down... or maybe even backs up.

I was actually fishing at the Dam yesterday when they cranked up the generators. For 30 minutes to an hour the very heavy flow was causing a huge amount of turbulence and heavy waves when you got within 30 or 40 yards of the intakes. However after about an hour, the heavy turbulence and big waves decreased significantly... although I verified via the TVA web page that the actual generation remained the same. I believe it's the same principal... an initial rush of water that really shakes things up... but slowly settles out after a while.

What do you think?

 

[Jerry]

Richard, I think it's just the tide. I see it all the time on the coast. (Best to you.)

 

[rsimms]

Jerry - 7/17/2008 1:46 PM

Richard, I think it's just the tide. I see it all the time on the coast. (Best to you.)

Same principal... it's just "man-made" versus "moon-made." emoBigsmile

 

[AThornton]

Very good theory Richard! Ive never really thought of it that way, but that makes a TON of sense!

 

[beetlespin]

When the downstream dam is releasing more than what is coming in the water level decreases and it runs out of the creeks, sloughs, etc. When it is the other way around it goes the other way. But Richard is correct, it seems to be exagerated right after they flip the switch.

 

[fish4thepeck]

A lot of times both dams will start generating around the same same time. One may be running more water than the other or vice versa. Then it can change as one cuts an extra turbine in and the other shuts one down or one may not be generating at all. A hydro turbine doesn't rotate real fast because they have multiple poles. It doesn't take as much flow to spin one once their up and running but initially to start one up it takes more flow.

 

[drumking]

I have been below WB dam when they turned all turbines on wide open before. You had to stay out of the turbelent water for almost an hour before you felt save to drift with the currents. It takes just about 1 hour for the water to equilibrate. This should support Richard's theory of why the creeks suddenly start flowing out and then level out after a time.

If the inflow is greater than the outflow, then the creek currents should run backwards like we see them do from time to time. But who knows for sure. Remember that a theory is just an assumption based on ignorance of the subject matter. emoUpsmile Sort of like the Darwin theory. They just can't find the missing link though. emoUpsmile emoUpsmile emoUpsmile emoGeezer Unless it lives in Soddy Daisy and makes rods. emoPoke emoPoke

 

[polo-dog]

drumking - 7/18/2008 5:30 AM

I have been below WB dam when they turned all turbines on wide open before. You had to stay out of the turbelent water for almost an hour before you felt save to drift with the currents. It takes just about 1 hour for the water to equilibrate. This should support Richard's theory of why the creeks suddenly start flowing out and then level out after a time.

If the inflow is greater than the outflow, then the creek currents should run backwards like we see them do from time to time. But who knows for sure. Remember that a theory is just an assumption based on ignorance of the subject matter. emoUpsmile Sort of like the Darwin theory. They just can't find the missing link though. emoUpsmile emoUpsmile emoUpsmile emoGeezer Unless it lives in Soddy Daisy and makes rods. emoPoke emoPoke

I'll send the Darwinists over there next week.

 

[SpurHunter]

drumking - 7/18/2008 5:30 AM Sort of like the Darwin theory. They just can't find the missing link though. emoUpsmile emoUpsmile emoUpsmile emoGeezer Unless it lives in Soddy Daisy and makes rods. emoPoke emoPoke

</p>

You just aint right Dickey!!! emoLaugh emoLaugh emoUpsmile emoUpsmile emoUpsmile emoUpsmile </p>

 

[Guest]

SpurHunter - 7/18/2008 8:54 AM

drumking - 7/18/2008 5:30 AM Sort of like the Darwin theory. They just can't find the missing link though. emoUpsmile emoUpsmile emoUpsmile emoGeezer Unless it lives in Soddy Daisy and makes rods. emoPoke emoPoke

</p>

You just aint right Dickey!!! emoLaugh emoLaugh emoUpsmile emoUpsmile emoUpsmile emoUpsmile </p>

emoUpsmile emoUpsmile emoUpsmile

 

[salecreekaviator]

There is about 50 miles between WB and Chick dams. How long does it take for the the flow to impact this much water in between? I suspect the impact of WB starting up would take a good bit of time to make its way that far down stream??? Conversely, once Chick turns on it would take a good bit of time before the impact is felt upstream very far??? The end of the bath tub without the drain is much calmer than the end with the drain when I first pull the plug.

 

[tennfisher]

Hmmmm. After reading this yesterday I tried an experiment. I took a 10 foot piece of guttering (the river channel), sealed both ends, and added a couple of inches of water. I then rapidly poured 3 gallons of water into one end. There was a surge of water to the other end of the gutter, and then it came back until it equilized. A couple of thoughts come to mind. Water doesn't compress very well. When turbines are spun up at Chickamauga dam this produces a surge that displaces the water below the dam, pushing it downstream. If water is not being released into Guntersville at Nickajack on an equal basis then there will be at least a small surge back upstream until it equalizes. In a similar fashion, I suspect the generators coming on at Chickamauga set the water in motion toward the dam in the Chick, then when the generators cut off, equalization occurs that results in the observed backward flow in WT. Of course, backward flow in WT would also occur anytime input from WB is greater than output from the Chick.

At least that's my hypothesis. I wouldn't go so far as to call it a theory.

Tennfisher

 

[mallardecho]

I think it is all related to NRG building that pond in his backyard. It could be the cause for the wacky water flows.

 

[team-d]

RSimms has it right, there are a LOT of dynamics involved. Watts Bar has been maintaining constant flows, Chick has been cranking it up quickly around 3pm for a few hours each evening. This basically creates a "hole" in the water above the dam - even if it is only an inch or two that's a whole lot of water. The highway across WT creek acts as a dam, all that water with a little bit of head between it and the main channel has to flow through the cut under the bridge. Same holds true for when Chick goes from 4 units to 1 or none, all that flow stacks up against the dam and creates a hump or wave, which in turn starts heading up the creeks - once that wave of water goes as far as it's energy can take it upstream, it turns around and heads the other way. Keep in mind it all doesn't happen instantly, the TN river is a pretty good sized creek. There are basically holes and humps or "waves" of water bouncing around very slowly - I like the man-made "tidal" analogy. Same below the dams, at first it is much more violent until the trough starts backing up and things start to stabilize a little more. AND, just when you think you have it figured out another variable comes into play (rain, wind, voodoo, etc)and everything changes...

 

[SpurHunter]

Hmmmm....I know you work for TVA, and have a degree, experience and all that, but I am going with my gut and saying its NRG's pond. Thanks Mallard, we can all rest easy knowing what the true cause is. emoWorthy emoThumbsup emoThumbsup