Nutty,
We pump water from a windmill to one of our ponds, and it works well for keeping the water level relatively consistent during the hot (and sometimes dry) Texas summers. However, we have the water splashing on rocks as it moves down a slight slope and into the pond in order to oxygenate it a little. Water straight out of a well lacks the proper amount oxygen needed for the pond, so that may be something you want to consider.
