The graph is a bit misleading in that the zero point is at the level that I installed the monitoring well. At the zero point the pond is about 7 feet deep. If you look at the fifth photo down (the one with the pond most full), the level shown there would be about zero on the plot. The water level in the pond is about a foot below the base of the trees when the graph reads 72 inches. Sorry for the confusion.
I have thought about just filling the bottom pool with clay. The soil is so bad everywhere that I think it would continue leak at an unacceptible rate. I will post some better photos of the soil later today.
