@Mifurre: What, do you say card combos shouldn't be of any importance when changing/adding a card? That's not the spirit..
Basically your idea makes it too strong. Additionaly, freezing a creature may be part of Water, but not of Flooding, because Flooding has nothing to do with ice. While the idea of delaying a creature sounds good, it's more of a Time effect. Besides, Procrastination would be stronger, since the chance for delaying a creature is 100%.
My suggestion for Flooding is something delay-ish, just that it wouldn't delay the creature like Procrastination. It'd disable the creature's ability for 1 turn. The chance for this can be discussed. Or it should work a bit like Luciferin, just for water.