Bill, the pond has a clay bottom and is not lined. It was dug out and built by my husband's cousin, who has an excavation company. He built to allow for runoff from neighbor's yard and to protect from flooding our yard. He packed it the best he could with the equipment he had. You can tell in the picture that by the time the water got to the rocks on the right (which is where he designed the spillway), the pond had to be considered full. That being said, there has not been much change on the waterline near the rocks on the right, which is good, I guess? I put a flag there just now to keep track.
I suppose this changes the calculations of how big the pond is and the water volume. It should still be 8 ft deep in the middle.
