J Wayne Smith

I know it's been many months but I wanted to wait and see what happened after this year's rainy season before adding a final update. So my soil analysis showed ~90% clay which is what my neighbor said he had. Which is the reason my dam has no core since the whole damn is a core as mentioned by others. I managed to raise the height of my dam to 16' high and widened the top to 15' while the base stayed at 40' wide. I have 1 rock based spillway that is 4' below the top of the dam and a second emergency spillway that is 1' higher than the lower spillway. We had torrential rains this Spring and I was nervous but both spillways worked flawlessly and the dam held up perfectly. And it ended up only costing me $3,000 which may be the best $3,000 I've ever spent haha. The dam is not leaking a drop anywhere and my pond is now ~5 acres in area and about 12' deep. I have a few bass in there now but will be stocking it soon. Thanks for all the help and feedback. This method wouldn't have worked without the high percentage clay that I have. I hope this helps someone in the future and saves them some money as well!

Update: This has been a very slow process but so far, it is working well. But I've only added another foot to the dam so far since I only have the weekends to do it now and it's rained several weekends since I started. The pond is now about 8' deep and not leaking a drop. It's going to be interesting when I get up another 2 feet or so and need to connect to the old spillways without washing away the new dirt on my dam. I think I may need to build concrete retaining walls on top of the existing spillways. I'll eventually post before and after pictures. I'm surprised this technique isn't used more often. Maybe because it's very slow. Maybe I could go faster. I'm going to lay on 4" this weekend and see. That would decrease my time substantially but it's working and at least it's a very cheap process.  I'll update again in a month just in case anyone ever comes across this in the future haha.

I forgot to add that I'm using a trash pump and excavating the sides of the pond near the dam that are under water and pumping that slurry to the old dam. I lay 3" of "mud" on top of the old dam and by the next evening, that dirt has dried out and settled and then I start the process over. The pond depth is now a little over 7' deep so I only have 3' or less to go because I've decided to stop at 10' deep. I'm also going to make the top of the new dam 12' wide.

The base of the dam is already 40' wide which to me is excessively wide for such a short dam. My pond has also experienced cracks in the dam during droughts but those cracks have only been about 6" deep. I thought about excavating the bottom but then I run the risk of piercing the bottom layer of clay and having a major leak. That's why I'm adding to the height of the dam and so far, it's working as planned. And luckily, if the new dirt somehow fails, there are no homes or yards or roads etc that are downstream from me for 7 miles so I'm lucky there.

I'm not 100% sure of the correct process but what I've been doing for the last few days is to suck up mud from the bottom of my pond and pump it on to the top of my existing dam in ~3" layers that are about 5' wide. So I've added about 12" total so far and since it has rained every day here for the last 4 days, the depth of my pond has risen about 6" so far and there are no leaks, yet. But then again, I have beavers helping me which I'm sure has helped a lot. I'm going to add another 12" by the end of this weekend so we'll see.

NEW INFORMATION. After much research, I am going to try to add the 5' of height to the dam using a hydraulic fill process. It is an extremely cheap but surprisingly effective method if you have good soil. I will only spray on a 3' layer first and then see if the first foot of new layer leaks once it gets above the original freeboard before I continue on up. It may take me a month or more though to get it done so I will eventually post the results.

Right. I'm getting a soil analysis right now. I've read that an ideal bass pond is 10-12' deep. So I need another 5' or so.

So if the current dam is 6-7' high and uncored but I want to add another 3-4' of height to it, does it sound "right" that I would need to drain the pond and core the whole dam just to add 3-4'? Would it be better/easier to dredge the bottom of the pond 3-4' instead? I just don't know anything about the bottom of the pond. Dredging it could cause it to leak. Or maybe I'm just stuck with what I have? I could understand coring the dam "again" if it was cored to start with but since it's not, that's where it gets me confused. Thanks for the previous information.

Good points. I have neighbors with dams within a half mile of mine who have dams that are 10' and 14' high. Also, our soil is very clayey which is why my original dam is made of nothing but clay. And the additional clay will come from the site just like the original clay did. Lucky it will small enough not to need any permits. And I will be getting more bids. Finally, we don't have any neighbors below our dam for 4 miles so I would think no one would be in danger.

Excellent thoughts. Thanks.