Neat thread John, I hope the pond works out well for you!
How are you determining the full water line? Is it from your spillway level?
Looking at my pond I don't have any idea what full pool will look like. I was thinking of taking a level and a laser out there to get a concept but I don't know how accurate that would be.
The full water line is determined from the lowest edge of the spillway. We used a laser level to determine water line and dam elevations all around the pond. The laser level we used is accurate to less than 1/8 of an inch over the distance across the pond. The pond at full pool is a rough oval about 130 feet by 105 feet. In my experience they don't stand at full pool most of the time. You don't have to use an expensive laser level to determine full pool. A regular telescopic level and rod will do; it only takes a lot more time, and two people, one at the level, and one with the rod. My pond builder has a high end laser level, so we used that. The wife and I laid out the pond initially with my relatively inexpensive telescopic level when studying its feasibility.
