I had read on this site that some are building cores of only 2' wide; maybe Mike Otto again?
By my reckoning, it doesn't seem important how wide a a core is if it is impermeable. A cereal bowl is pretty thin and it holds milk.
This concept was new to the pond builder who showed up to consult me this morning, but he found it intriguing. He felt that it should be at least 5' wide to allow for proper compaction. He didn't feel like the pond bottom was much of a problem, only the dam. I hope he is right. I'd hate to keep dumping large sums of money in a literal hole in the ground.
Most clay pond liners are 3', so I would guess you would want at least that, even for a core barrier.
Did you ever get a $ amount figured out to line the basin with clay, and is it cheaper?
Like you said, you don't want to keep throwing money into it on "may be's". So, if you can't afford to do it the recommended way, best to wait and save up till you can...meanwhile keep researching.
EDIt---oops. I don't know why I was thinking 3'. Looks like 18" or more for a clay liner.... Hopefully somebody will chime in and give a confirmation one way or the other.
