Thanks Kent! Now that I have had some time to think and remember ponds that my neighbors built in the past few years, they used only the clay removed from the site to line theirs. Like most landowners in my area, they didn't go very deep and, unfortunately, their layout is simply a formless basin. I wonder if the deep area of my dream pond would require a thicker layer of clay due to the increased pressure. In ponds with a possibly porus soil throughout, I have noticed that 12" is suggested as a minimum. Perhaps with shale,this could be reduced by half in the areas 5' deep or less. These areas will, however be where aquatic vegitation puts down it's roots, and I'm wondering if the roots need a minimum thickness to support growth. I say this realizing that weed growth will have to be kept in control to provide habitat rather than a nuisance. There will have to be one or more mud flat areas to serve spawning and I imagine that 3' deep would be best for these areas. What would readers suggest as the best depth and vegitation scheme for these areas?
