How high above the water should the dock cross-members be to protect them from ice upheavals? I am building a pond in NY Fingerlakes and we get ice (liquidsquid has measured over a foot on his pond). I decided to go with cut up telephone poles for the posts, and put about 3' of concrete in the holes which are about 4' below the pond surface. I have see significant chunks of ice pushed up at ice-out on lakes in this area. I don't expect to aerate at the dock. Is this an issue and how high above the water should cross-members be?