I'm just hoping it doesn't leak. My pond builder said he guarantees it won't leak. I hope he's right! I've got his dozer still in my yard. Isn't possession nine-tenths of the law? I could clear some trees with that D6...
If you have good clay with no inclusions of other material that could cause leaks you probably are fine.
We hear about the leaky ponds here on PBF. But likely hear of few that didn't leak even though they may not have had proper compaction. Proper compaction is a necessity with some soils, an insurance policy with others. In our area we don't worry much about compacting the bottom of the pond unless a seam is found. Core trenches and dams normally get attention to proper compaction, the bigger the pond the more attention paid. Small ponds problems are more easily rectified than large projects. Lots of cow ponds in our area are nothing more than the top soil scuffed off the dam area and the ravine cleaned out and pushed up with a dozen. Most work fine, a few have dam seeps and the occasional one that gets into a sandstone seam that is not fixed won't hold water. But that is "here". Our solils and subsoil generally hold water very well. Build a field terrace with a low spot and you have a "pond" till it evaporates.
Many areas are not so "lucky" with their soils water holding capability though.
