Okay let me address some of these assumptions.
When the water came down Tam Sauk, that drop was a little more then the 3' to 45' or so of a Taney breech. You assume that the dam would be completely gone instantly, Shadow Rock and River Run would be full, and BS would be at normal pool. The water wouldn't stop at Barker, but it would be slowed, which would raise the water. BS, like it or not, after all the initial flow, would rise less than a foot.
River Run under water, yes, but not from one rain. This all came about over terrorist breeching dams, and the dams here just aren't that attractive, especially Taney.
I would like to get a peek at what the river would look like without Powersite, even though thats not possible, I think I would like it. I have some memory of the White before TR, and a lot of memories or the Osage, South Grand, and the Pomme De Terre before Truman, and I liked them better.