Thermocline in a TVA reservoir?

[Steveo-1969]

I guess I'm asking specifically about Kentucky Lake as I'm headed there next week on vacation. Can/does a reservoir develop a thermocline in the summer? I was assuming there would be no thermocline (at least in the main lake) because of the frequent current running through the lake.

[roadwarrior]

Most of the TVA lakes do not, but Kentucky Lake does. This is by far the largest and deepest

reservoir in the system. In the summer time ledge fishing is king! Two of the "secret" lures

are big hair jigs and spoons. 3/4 oz Ledgebuster is another popular option. I am a BIG fan

of the Rage Tail Thumper (Blue Fleck).

 

 

 

[TnRiver46]

People catch catfish 70+ feet down all over Tennessee River, I’m guessing that wouldn’t be possible with thermocline

[RoLo]

 

With regard to summer thermoclines, be wary of anglers who don't discriminate between 

fish depth & water depth. That is to say, bass 20 ft deep may be suspended over 100 ft of water. 

 

Roger

[Tennessee Boy]

I've never seen a thermocline in or near the channel on Kentucky Lake.  I can't say that I look for one very often since I've concluded that they don't exist.  

 

I agree with @TnRiver46 on catfish.  I've caught them in some very deep water in the hottest part of the summer.  I don't think they're suspending at 20ft and then diving down to 60ft for a quick meal.

[Steveo-1969]

Thanks for the replies guys. I can understand a thermocline developing in some of the deeper bays of KY Lake where the water isn't affected as much when they are generating current. We've swam in them before and there is definitely a layer of colder water as you swim down. But I've never thought about finding the thermocline with electronics and fishing above it.

 

I think we are in for a tough week of fishing next week. We generally stick to secondary ledges out on the main lake but looking for a thermocline in the bays may give us something else to try.

[Glenn]

This video is relevant:

 

 

[roadwarrior]

[Steveo-1969]

2 hours ago, Glenn said:

This video is relevant:

 

 

Thanks Glenn. Watching this video is actually what got me thinking about the existence of a thermocline in a reservoir like Kentucky Lake. If you mentioned this in the video I missed it?

[Glenn]

3 hours ago, Steveo-1969 said:

But I've never thought about finding the thermocline with electronics and fishing above it.

Actually, I was responding to ^^this^^ because that's exactly what this video is all about.

[TnRiver46]

4 hours ago, Steveo-1969 said:

Thanks for the replies guys. I can understand a thermocline developing in some of the deeper bays of KY Lake where the water isn't affected as much when they are generating current. We've swam in them before and there is definitely a layer of colder water as you swim down. But I've never thought about finding the thermocline with electronics and fishing above it.

 

I think we are in for a tough week of fishing next week. We generally stick to secondary ledges out on the main lake but looking for a thermocline in the bays may give us something else to try.

Water below surface is always colder than the top unless it’s the dead of winter. I’ve not spent Much time on ky lake but the bays on all the other TN river lakes are effected by current. There is no flat land here so water is always rolling downhill. Unless you are fishing very close to the dam, the effects of when they turn them off and on are felt hours later. For instance, in Knoxville the holston river is controlled by Cherokee dam. Cherokee pumps water almost every afternoon but it doesn’t reach Knoxville until morning and is typically raging fast until mid afternoon. It’s usually 12-16 hours before the effects are felt downtown Knoxville 

[Steveo-1969]

53 minutes ago, TnRiver46 said:

Water below surface is always colder than the top unless it’s the dead of winter. I’ve not spent Much time on ky lake but the bays on all the other TN river lakes are effected by current. There is no flat land here so water is always rolling downhill. Unless you are fishing very close to the dam, the effects of when they turn them off and on are felt hours later. For instance, in Knoxville the holston river is controlled by Cherokee dam. Cherokee pumps water almost every afternoon but it doesn’t reach Knoxville until morning and is typically raging fast until mid afternoon. It’s usually 12-16 hours before the effects are felt downtown Knoxville 

Dang, I never thought about water running downhill and moving water out of the bays. That makes sense! We fish the northern part of Kentucky Lake, from Kentucky Dam to about 20 miles south (water runs from south to north). I'll be honest I don't understand how the dams and generating current really works. But I'm guessing being only 20 miles or less from Kentucky Dam when they pull water through that dam we can see/feel that generation fairly quickly?

[TnRiver46]

24 minutes ago, Steveo-1969 said:

Dang, I never thought about water running downhill and moving water out of the bays. That makes sense! We fish the northern part of Kentucky Lake, from Kentucky Dam to about 20 miles south (water runs from south to north). I'll be honest I don't understand how the dams and generating current really works. But I'm guessing being only 20 miles or less from Kentucky Dam when they pull water through that dam we can see/feel that generation fairly quickly?

Yes it should start moving in a couple/3/4 hours if you are only 20 miles away depending on volume. Higher volume moves faster.  The current right now is not nearly as strong as it will be in fall and winter . Check TVA.com for the volume that goes in an out of each dam each hour. Then when you click “operating guide” it will show a line graph of the lake elevation each day 

 

here’s the current conditions at KY dam

 

About 34000 cfs, that’s minimal for KY, in winter it’s often over 200,000 cfs