perfectly legal as long as you don't do anything to it that is not intentional manipulation. you can still travel through the planted millet as long as you are doing a "normal" hunting task.(decoys in or out, downed ducks, dogs, etc) you and the gw and determine if what you were doing is normal or not. I've never seen a need to manipulate millet in any kind of way though. as far as flooding goes, the feds classify that as manipulating the ground, not the millet.