we recently doug a pond,approx 14 feet in diameter and about 4 feet deep... it’s all clay too we live in Ohio We left the mounds of dirt (clay) around the peremiter of the pond, we plan on getting a pond liner.. which apparently are expensive! If any one knows a good place to order on line, please let me know. Not sure if I should plant some fescue grass around the outside bank or not... we have a lot of research and planning to do, but the end result will look sweet! ( I hope !? ). Lol