would like to ask, im in the dreaming phase of a pond. while i am reading these answers, it makes me wonder , to dig past the sand. and end up with a spring. if he does that. cant a person just hook up a pump or windmill to raise the water level when it drops. where i live, the water table fluctuates, but doesnt dry up, im within a half mile from a large river, and i want to dig as deep as i can. i know i will hit sand and water before 18 feet. what do the experts say about digging past the sand and using a windmill for a pump?