In Arizona large fields are often flooded for irrigation, instead of using more traditional sprinklers. The water takes several days to absorb into the ground and in the meantime, the extra water usually attracts some new friends.
This picture was taken at my school, and is facing the Head Start program that is attached to the school. The students thought it was pretty cool to have ducks in their "lake". In fact, a few weeks later when the fields were irrigated again, Canadian geese showed up too.