Thank you for the response, the reason I was asking here first is that I don't want to spend extra money on something that will not work. I was thinking to place liner (overlap) over the area that is currently holding. But regarding steep slopes it makes sense, even with clay it's an issue.
My best bet is to just let the water drain as much as it can during dry spell and just rework the pond walls with more clay. And hope for timely rain...
Due to recent heavy rainfalls, I had some additional erosion at the top, but it helped raise my pond holding level couple feet. I guess the eroded clay and sediment sealed cracks that I had in the lower levels. So I am a little over half full on average (7-8ft of water)
