We are on the process of trying dig out and compact a ~1 acre pond that has leaked significantly for years. It is located in eastern Nebraska and the soil is supposed to have sufficient clay. The pond also has a significant amount of bentonite that my grandpa put in there trying to get it sealed.

We dug all the muck out and are now compacting it with a double barrel sheepsfoot roller and a jd 5100E. Most of the pond is packing pretty well and is now getting to the point where the sheepsfoot barely even makes a mark. There are like 3-4 spots though that seem to just be mushing under the weight of the track tires and roller. You can see the soil squish out away from the load points rather than press down and compact. We tried digging a hole with an excavator and to get to what looked like good soil and mixed it into those softer areas but it still just seems to never firm up. My question is so you think this is a moisture problem (too wet) or should we dig those areas out with an excavator and put in different soil and compact again?

I will say too that when we were digging we ran into a lighter color material that seems more greasy/slimy and mushy. I don’t know if it is another sort of wet clay. It seems to make a ball fairly easy but doesn’t seem to compact like some of the other soil or the bentonite in the pond.

Additionally, if anyone has an contacts in the Omaha area that are good soil or pond building guys that I could contact about hiring as a consultant for a day to come take a look at our project that would be awesome. We have gotten this far we just don’t really have the knowledge about soils to get it across the finish line.

I highlighted the soft areas in red. The other areas seem to be compacting fairly well. I also had a post on another thread that explains another thing that seemed to happen in these same areas where the tire of the tractor would fall into a “hole” and feel like it was going to tip over. There is also some photos of the soil difference in that thread.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=41561&Number=541560#Post541560

Kris,

teehjaeh57 is a good consultant based out of Lincoln. I don't know if he is swamped right now, or if things are slow.

You might try sending him a PM and see what he suggests. He should know your soils fairly well, and may be available for a site visit.

(His email address is also available in his profile, but I don't want to print it in the forum.)

Good luck!

I would say that the areas are too wet. If the soil is dug out from that area, and it's let sit for a day, does water collect or bubble up in those areas?

Maybe if you can get some good compactable soil that is on the dry side, put that in the hole, then start the compaction process you might be able to get ahead of the excess water problem. Those areas are probably the areas that you had problems with water exiting your pond. Now that there is less pressure from the pond side, the water is seeping back in. I don't know if putting a layer of SoilFloc down, then covering it up with good clay and compacting that would work - ask TJ.

We ended up doing just this. It does seem like the material, once dried a little, is good clay as it picks really well. When it is wet however compressing the ball in your hand makes it just squish out your fingers. We dug the area out and packed back with dryer good dirt under the top soil of a side hill around the pond. It is solid now. We pulled up the saturated wet material and are letting it dry before be scatter it back across the pond floor and compact for another layer. We have successfully got a hard compacted on in the bottom now so we figured even if it is not the right material it will be on top of our already compacted pan. I have been talking with TJ and do plan on getting some polymer but we are kind of racing the weather holding out here in Nebraska. We want to get this as far as we can before we start getting snow that will hopefully start filling the pond back up.

Thank you for the responses. This forum and TJs help has been extremely beneficial. I plan on writing up a full story on what we did at the end of this project as it may be helpful for others with similar situation.

Hey Kris,
We'd be interested in publishing your story in Pond Boss magazine.
For others interested in submitting stories, here's what we like:
Goals,
What you had to work with,
What you did to "fix it".
1200-1500 words, Word document, single-spaced, one space after a sentence, indent each paragraph, Times-New Roman, 12 pt font.
5-7 photos that help tell the story.

Email me with story ideas.

Bob

Sorry for the late reply. I haven't logged in for a while. After giving it some time, with as little of rain that we have had over the last couple years here in Nebraska, it is hard to say how much of an improvement all the work we did accomplished. The pond has filled up to have the bottom almost all the way filed up and is probably 4 feet deep or so in the deepest part. It still seems like it reaches a similar level that it did before and plateaus there. Like I said before, we have been in pretty severe drought conditions in our area and in the last couple years you can probably count the decent rains/snows on two hands. I do have a batch of polymer to put down but I have been waiting for the level to get higher before I put it in. I still have a couple hundred pounds of bentonite clay that I have been throwing out there and this spring I started doing some bentonite slurry injections in an attempt to slow down any seepage so the water level will continue to rise. I am also exploring trying to figure out a way to get more water flow into the pond as right now my solar well will only put out about 5 gpm when the sun is shining.

It has been a bit of a let down. I thought the all the work we did would really do the trick but at this point I am reluctant to claim success. As of right now it is still just a mud pit that I burn money in...

Hey Kris been a while. Reach out - let’s huddle and strategize. Happy to help in any way I can.

I wonder if the exposed compacted clay didn’t stay compacted during freeze and thaw cycles. Around here there is nothing better to fluff up soils than winter.

Totally agree with liquidsquid.

I deepened a little groundwater pond last fall and just dumped the heavy, saturated clay on the bank. It was so dense, that it was unworkable with the low HP equipment I had.

Went through there last week and that clay has been turned into loose powder. Where there were old toothmarks, you can even see how the clay clods have expanded through miniature versions of frost heaving.

IMO, if you have a pond that is only sealed due to a clay blanket, AND that pond remained dry over the winter in a freeze-thaw climate, then you may need to moisten and compact in the spring before the rains return.