I'm new to this forum, so this topic may have been covered. I'm building a 1.5 acre pond with a watershed of approximately 7 acres of woodland. My contractor, who builds a lot of ponds and lakes, says that most of the problems he sees on dams center around the overflow pipe. He suggests eliminating the overflow pipe in favor of a spillway only. I think the forumla is: 1/2 the watershed area divided by 2 + 15 feet. In my case 7 / 2 = 3.5 + 15 = 18.5 ft of spillway. Any thoughts on this one?
