Chances are the drained pond was a temporary storm water retention pond that the developer installed during the construction of the neighborhood. In any case, I'm sure the pond was drained for good reason. As former builder I can assure that builders don't do expensive things like draining a pond for no reason (read: without being forced to). So I agree with Mike, give the builder a call to find out the reason they drained it, but I wouldn't expect to be able to restore the pond in a protected area without jumping through a lot of environmental hoops. I hope this helps.