Had core problem

Welcome to PB!

I can see your concern. A full foot seems like a lot. I'm far away from being an expert on pond building (or even dirt for that matter), but have to ask...Do you think it was clay that settled or could it be a fair amount of top soil only?

If it was clay, that area did not get compacted properly, or at all. My old pond had its dam breeched so that it could be drained and renovated. No sheep's foot compaction when the 10 foot wide crevice was refilled at my pond; only bucket tamping the layers and the tracks as it laid the layers down. It did not settle any visible amount and it's been 4 years.

It's hard to say if you will have a problem. What does your contractor say about the settling?

How was the core compacted and in what thickness lifts?

Core

A sheepsfoot was used and I do not know what "Thickness lifts" mean

Sorry just looked thickness lift up, the clay was continually compacted as soon as it was dumped and dozer leveled out.

Just running a sheepsfoot roller over the clay once or twice won't compact it, it has to be run over the clay enough times so it starts to "walk up and out" of the clay.

Say a layer of clay was put down. The feet on the sheepsfoot roller sink down until the barrel of the roller is on the surface. It has to be drug back and forth until the roller is no longer touching the surface of the soil.

For an unbiased opinion that won't cost you anything, call the local NRCS office and see if they can send someone out. Ask them if they can determine if the dam core is compacted properly.

Address: 2040 Riverfork Dr, Huntington, IN 46750
Hours: Opens 8AM
Phone: (260) 356-6816

Thank You!!!
I called this morning and they will have one of their Engineers come out and look at it. Will let you know what they say.

Great!!!

Well - not so great - I called again and was told they do not help with Ponds. So I now left a message for the DNR to call me. Lets see if they can help.

NRCS DOES help with ponds, you may need to physically visit the office and speak to the head honcho. DNR won't help at all.

Well - Allen County does not - I even called the state NCRS office and they called Allen County Office and talked to them with the same response.

For an additional note - the contractor came out last night and we were able to sick a 4' rod into one of the sink hole cracks, I could see on his face we have a large problem as the core is cracked in that one spot. So with that large crack where is the water going. It is forecasted to rain this weekend so we agreed to come out and see if there is any clue how bad the situating is! (Where the water is going) otherwise he will have to excavate and find the channel (Tube).

I will also say I have a good contractor just a messed up situation

Now for the laugh - I was talking with one of the state engineers and during the call he stated he wish he new more about septic's. So I spent a 1/2 hour explaining Aerobic and Anaerobic systems and how to revitalize a degrading system. But at some point you will need to declare it is dead.

There are a lot of old flood control "watershed lakes" that were installed by the Corps of Engineers in my state. I saw guys up surveying one time when I was out fishing and stopped to chat with them. They said a benchmark was installed on the top of every one of those dams. They drive out every X years to inspect the dams and shoot the level of the bench marks. (I think "X" was 5 years.)

He said if the benchmark has not moved they just move on to the next dam. If the benchmark has moved they do a more thorough visual inspection. He said that in his experience, when the benchmark is going down, they always find a problem.

Your contractor may have messed up on something. On the other hand, he may have done everything exactly right and it still didn't work out properly. Soils can be highly variable beasts.

Mike Otto (one of our dam building experts) has stories in his book of doing everything right but some quirk of the earth caused a dam failure.

Good luck on your project!

Thanks - I really do not believe and am not saying my contractor done anything wrong, they have been great to work with but I am not a dirt boy. Contractor will fix but I know these services like NCRS has information and expertise that could be helpful plus I would just like to know what happened so we can repair without a lot of more excavation that again may disturb the core.

And yes - I was ME (EE, ENV) until this Parkinson's sidelined me and there were projects that just never seemed to go right also.

Otto,Lusk, me, and a couple of other guys were talking. Somebody mentioned a leaky pond and the reasons for leaks. Mikey said “If you want a pond to leak, just let me build it”. Even the best can have things go wrong.

If you have never made a mistake - you do not do anything

The most successful people I know have literally made the most mistakes in their lives - because they are always trying new things in an attempt to improve some process or product.

I have immense respect for these people. It is also why I like going on Pond Boss, there are so many people here that are tinkering to make things better! They tell us what went right, but more importantly - what went wrong.

Unfortunately the NRCS offices here in Indiana seem to be very hit or miss as to the work they do and the knowledge that the people in the office have. Also, unfortunately the offices cannot cross county lines to work in a different county. The office in my county is like yours, not any help at all. The office 2 counties over is just the opposite. the people there know their stuff, and they have equipment to take deep core samples, etc., etc.

I hope that you get it resolved quickly!!

Took me long enough to figure out how to shrink the picture, here it is.

Also my contractor and I agreed to wait until the next good rain to see if we can find where the water is going.

Welcome - if you have any thoughts would be great - beats us what is happening. The core was great, compaction was great, it has to be an anomaly underground or there is an Alien screwing with us.

The long sinkage was first, the in the back of the picture you can see the second sinkage, now there this a third area starting to happen right in front of the original sinkage. Well if nothing else I had a lot of clay to get rid of

It looks like the clay core is settling. To me that means not enough compaction of that area. Whether the lifts were too thick to properly compact, or there was too much or not enough moisture in it to properly compact it I don't know. If I am wrong, then I have no idea what is going on.

When we put our dam in over 20 years ago, my wife, me, and our evil spawn were walking down the new dam, and when we looked back, he was gone. He fell into a a Volkswagen sized hole on the top of the dam. The builder showed up the next day and tore out that whole section, layered and repacked it, and we haven't had a problem since.

Thanks - since there are no visible leaks and this is on the shallow side of the pond do we need to excavate and repack?

* this section was not cored until November in Northern Indiana

Also the pond is not full yet, so I am skeptical if we may/may not have a leak? I am still on the side of wait and see for now.

Pack it as best you can, and see how things go. It seems like your contractor is trying to help, so working with him or her seems like a reasonable way to proceed.

^^^^^ I'm with RAH. November wasn't THAT cold, but if the clay that he was compacting had frozen bits and parts, it wouldn't compact very well.

Well - the sinking and total area keeps expanding. Can not do anything until this stops.

If your contractor is trying to help, be thankful and try to work through the challenge.

Yes they are - I guess I am just venting

I think RAH was just meaning alot of them wont even answer a call after they get paid. Sounds like you found a good one willing to fix it. Also it's fine to vent and ask questions. The more minds and experiences you can gather the better informed you are.

I have a very small area (2'x5') that settled the same when my pond was dug last fall. It settled 4-6 inches. Contractor said it was the spot where he took out a 4" plastic drain tile. Contractor is going to pack it in with more clay we have leftover. He also stated he would redo anything if I ever had a problem. He has been really good to work with so far. Your not too far from me, I am in DeKalb County.

Thought I would post an update - seems like the sink hole just will not stop. Over this past rain event the length nearly doubled and sunk some more.

Has anyone here heard of or seen "Internal Migration Piping"?

I had not heard of that and did a quick search to find this fairly simple explanation. It is on page D-6-9 located here...

https://www.usbr.gov/ssle/damsafety...ankmentsAndFoundationsWithAppendices.pdf

Pretty scary...I hope that's not your situation.

Stan,

I am a geologist, NOT a dam expert, or a civil engineer. However, if that soil was compacted during construction, then it sure does look like you are suffering soil losses due to internal piping.

I think the most common internal piping route is along the outlet pipe - which is why seep collars are installed. You said this is on the opposite side of the dam, so that is not the problem.

Noel's link shows some illustrations of the other types of piping scenarios. Did you have a bed of Indiana limestone underlying your topsoil layers? If so, you may have a fracture open in the limestone. When the soil is saturated, soil and water both migrate down into the fracture. The resulting void makes it easier for additional soil to find its way into the fracture the next time. Hence the "piping" description.

Another possibility is that you are connected to an old drain tile system from when the land was farmed. Did your acreage used to be farm land? If you don't know the specific history of your ground, is there a farm neighbor you can ask to see if he has drain tiles on his land?

You should have cut some of these tiles or pipes during construction if they were present. Maybe ask your contractor if he saw any?

Another possibility is that you have piping occurring into the pond itself. Soil and water is flowing from your bank into a lower level in the pond. If you are able to easily drain the pond, you should see some weird feature or even a mud volcano on the bottom of the pond.

Good luck, Rod.

Thank you so much!!!

Outlet is on backside of dam and water level is not there yet
Limestone - no
Even though this was used for a cattle farm (40) years ago - the terrain is was not suitable for grain and tile would have been near impossible to drain, and yes there is a neighbor who knew this acreage and he did not know of any tile.

Contractor did hit sand at 22' depth, but it was sealed. I would not say this is the issue because with every rain event the level goes up and I do not lose level between events.

I am guessing it is the last possibility, because just during the last rain I had marked the water level and the level did rise ~1", BUT later that day when the rain had stopped for nearly 8 hours I noticed the level had risen another 1"

The collapse area grows with each rain event and I have walked around the entire pond several time and do not see a discharge.

As the area grows the contractor is hesitant to do anything.

What would happen if I put tracer dye into the collapsed area, if it is going into the pond would this not show instead of draining?

And last would it be better to excavate now to stop the piping since the collapsed area has not sealed it?

PS: i can stick a 3' rod into the crevice so the cavity is bigger than what is seen in the picture.

Thanks Again

"BUT later that day when the rain had stopped for nearly 8 hours I noticed the level had risen another 1""

That is not proof that there is piping into the bottom of your pond. There is always a time lag when water is running through a permeable media. A 1" water rise after 8 hours sounds reasonable.

I spit-balled a bunch of possibilities for piping problems, and it appears that they are all unlikely. You certainly have a mystery wrapped in an enigma!

I looked at your last photo again, and noticed that the collapse feature seems to be following the outline of the pond. One more possibility, is poor initial compaction by the contractor. It looks like he may have missed one strip for compaction right where his embankment ties to the edge of the undisturbed soil a few feet past the edge of your designed pond shoreline.

Hopefully, you have more rain coming. My advice, see what your pond does when it reaches full pool. If it is holding water, then I think it is unlikely that you have a significant piping problem just a few feet beyond the shoreline.

Best wishes!

Well we had a good rain event last night and it only traveled a foot the other direction now, What I now see what had happened - the contractor did not complete the pond in one visit, and there is a separation of the core (see picture). So it looks like they did not know where they stopped and started a few feet away when they returned. Also there is a small slide on my pond embankment right where this stops and a pipe formed between the snafu. This is where the sink hole started in the first place.

I also believe it finally collapsed on itself as it really did not creep this time - just sunk another 6" and never held water before. So like what was said earlier in the comments, all my missing dirt is in the pond.

So - I just need to get it dry enough so they can get an excavator here to fix, ah-ha this is why I could stick a 3 foot rod into the crevice there as the core stopped.