Thanks for the reply.
I currently have two small ponds that are essentially water table ponds. The soil has a pretty good clay content where they are located.
I am considering combining the two ponds and making one large pond, and will have well water available if that becomes an issue. I was hoping that the ability to have a clay bottom / sides would (should) prevent the leaking that you experience.
I certainly can understand your frustration but I think even at the lower level, it still is really nice.