I dont think food is gonna be an issue unless the flood water stays there for three or four months and nothing grows. Post flood grass and other natural food plants do pretty good in flood water deposited soil. But then again, if you have an unusually high deer population that does in fact depend on crops, then I guessyou might have a problem. I would have to take a look at past post-flood deer harvests and see some pretty bad declines before i would lose any sleep over it.