Hey guys pond construction starting Tuesday, i need some informative info on my dam.what I have is a 100ft or taller cottonwood tree that will be directly behind my dam/ levee.the base of tree is easily 3-5 ft in diameter and will probably be a good 15-25ft from the water surface of front of dam.this is only one of very few trees anywhere near pond which would be only source of shade, should i have it pushed down or leave it if i can?