...interesting thread. I have been monitoring the same thing in our new pond project. I don't have a measuring rod, but the water is still low enough that the corrugated drain filter case is still exposed. I can use it for water level reference. It seems that I might be losing 1" - 2" per week. As I am absentee, it is difficult to do a scientific bench test, but when it goes down an inch or two in a week in cool, Fall weather, it seems like more than evap.
