How big is the pond? The sediment will keep slowing it down, but I don't think it will ever completely stop it up like a good 2' of clay will.
It depends on how much patience you have. If good clay is available close to the pond, I'd fix it. If the pond is as big and as deep as you'd like it, just dig it out another 2', and line it/sheepsfoot roll it back to the orig. depth and be done with it.
The pond is a triangle of sorts... 120 ft long X 80 ft wide with the point if you get me about 10ft wide. The seep is about 20 feet long with the worst area in the dam is about 4' wide. I put bentonite in the bad area. Silted it up good. Then I covered it with a bit of soil. I think it has stopped for the most part.
I'm wondering if the sediment will block it enough over time that I don't have to do it weekly. Yearly would be fine. Even once every couple months would be ok too.
Clay availability? Not so much. I would have to have it trucked in. The the pond is also 1000 ft from the road without the best access. The pond down a hill through a bit of woods. Then over the glacial rock deposits. I'd need to build a road for a truck to get back there. I'm currently adding to the top of the dam where it was over topped with soil from a small area of dense soil I found. It's a heavy dense slit/clay mix. Not really what I would say is "good clay." But it's stable, sinks easily, and gets hard after a bit even in the water. If I had a ton of this stuff it would be great. But the borrow area is smallish... I could get at most only 20 or 30 yards.
I'm kinda nervous about digging it out too much. What if it's the silt that's holding the water. I'm thinking I may just keep mixing it's mostly organic. If I get heavy rain with out lightning. I may just go down and rake the crap out if it and let it run over the spill way.
