When most of us are talking good spawn we are thinking in terms of the high water lets them spread out as DD say's. In that the bigger picture is more cover as in brush, trash, stickups, gravel, rocks and such for them to nest and more and better cover for the fry to hide in. Thus you end up with a much better recruitment class where with normal water levels a lot of the fry are eaten by predators. Also all the flooded new ground provides more food sources for all your adults and fry.