For those of you who frequent Ky and Barkley at what CFM generation do you start to get noticeable, appreciable current in the main lake?

This may sound stupid but where do you first see that current? Up near the dam or farther downstream or in the creeks when they really pull it?

I know I can typically find some fishable current in the canal going one way or the other but at times the boat traffic makes it hard to fish.

Thanks.