I'm renovating an old family pond to hopefully stock with CC this fall. It's about half an acre and about 16 feet deep at the deepest point. The southern bank of the pond is pretty steep and there are a few spots where the clay isn't there anymore. I don't know if it happened during the draining process or was already there. I took pictures of the pond and would like to hear from you all as to whether this is a problem that I need to do something about before letting the pond fill back up. This is a shot of both spots from across the pond:
Here's a closer shot of one spot:
This is a closeup of the ledge on that spot where the breach looks like it started:
I dug down a little in the sand on this spot to see if maybe there was clay underneath and there wasn't. But I hit water at 6-8 inches down. There hasn't been water over that spot for about six weeks. Does that mean it's at the water table level and won't be a problem? Here's a photo of the hole I dug:
And here's a pic of the other spot:
Any advice you can give would be very helpful.