When my pond was completed, that night we had a weather system stall on top of our part of the world and dump 7"+ rain on us. Between the nearby creek and the huge aggressive watershed that I have, my place filled up literally overnight to the point of breaching the dam. I began to stock the pond 2 weeks later with forage fish (FHM, CNBG, RES...). This was August 2014. It was not until the spring/summer of 2015 that I started catching different species of fish that I had never stocked. They had also spawned either the summer before and / or that spring. I believe fish caught up in massive drainage situations have no choice but to go with the flow of water. My water came from up north of me and I know of several ponds up north of me (looking at google earth). Since then, the creek has been re-dug and re-routed so hopefully, I will not have any more issues like that reoccur.

I do have a nephew in SW Louisiana that has a 4 1/2 acre pond on 45 acres in a flood zone. He indicated that the bigger fish (LMB) appear to stay put during flooded times, but as mentioned above, he gets his fair share of choupique (bowfin), gar, and an occasional alligator that make it in to his place. I guess it would be depend on the situation, the geographics, amount of water, and the avenue of water coming through.

...when in doubt...set the hook...