leaky farm pond

   / leaky farm pond #1  

tbergman

Member
Joined
Jan 4, 2019
Messages
29
Location
Tahlequah, Oklahoma
Tractor
Branson, Kubota, and Case
A couple of years back, we bought a 47.5 acre horse farm with a nice pond on it. Unfortunately the pond leaks down to about a foot of water within a couple weeks of rain. I have seen it full once, and it fell about 6 inches to a foot a day until it was about two feet deep, then it slowly subsided to about 1 foot deep over the next month or so. It never seems to get any lower than that so it appears not to be leaking in the very bottom. There are trees up to 8" in diameter growing within a few feet up the bank from the 1-2' water level. Poking around while removing some trees I could reach with the backhoe, I found traces of what looks like bentonite, suggesting that the pond has never held water, despite being 15-20 years old, and some half-hearted efforts to seal it up. I have looked carefully for evidence of leaks through the bank and found none. There is no stream below the dam, even right after a pond-filling downpour, so the water must just be draining through the rocky soil. Our soil looks redish, suggesting clay, but it is filled with gravel and quite crumbly. We are in northeast Oklahoma, near Tahlequah. Bentonite and other synthetic pond sealers are all much too expensive, so I am thinking if I could just find a dirt guy who has a clay pit, and get a couple dump trucks of good clay, I might spread it around the edges and work it in. So far I have been unable to locate such a resource. I have no experience in pond building or repair, so any advice on how to seal up the pond on the cheap will be greatly appreciated. For now, I am working on clearing all the trees from the dam. I know they cannot be helping the issue, but I do not think they are the cause either, since none of them have deep roots at all, even though they are pretty large, some are over 20' tall. I have some great resources; a tractor with a road boss grader and bucket, a backhoe, and a small dozer, so I can handle the work myself, once I figure out what I am doing...
 
   / leaky farm pond #2  
The first place to go is you're local NRCS/FSA office and get some recommendations from them. There might even be some cost share funds you can sign up for.. I would not mention the tree removal you have done and plan to do. Just don't... I'm not getting in the weeds on this issue much,, but the "Clean Waters Act" COULD come into play here, YES it could effect you. but it might not.
***** has reversed some of the very very far GOV overreach on private landowners.
With that said.
In the past there were a lot of these type structures like yours to slow down run off and help ease flash flooding, I have no way of knowing that's what you have or not. I do believe you are thinking correct to remove the trees as roots and levees do not go together.
You have to maintain control of the water, simply getting the seepage stopped will cause the pond to fill and where's the water going then?
Over or around!! And could cause serious failure to the levee and cause damage down stream.
Go see the NRCS get their opinion on a water control structure. It's what they do..
 
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   / leaky farm pond #3  
Interesting problem. My neighbor has a similar issue. He spend a great deal of money excavating, what is basically fractured basalt, over a layer of sandstone. The neighbor, who shall remain nameless, has a habit of hiring idiot contractors. The excavators went right through the sandstone layer. So its fractured basalt, in clay, and a bottom that went through the sandstone layer. I got asked to look at it, cause it wasn't holding any water. An EPDM-rubber liner was out cause that was too expensive, so I suggested Gunite. He again hired an idiot that had no idea what they were doing and the Gunite mix was wrong and the liner just deteriorated into a mess of chicken wire and aggregate. Since then I have suggested an infusion of a clay slurry with fine wood chippings and work it up till it holds water. He has very fine clay available on property and a chipper and a wood lot. So I think you are on the right track with the clay idea. You are looking for a way to plug this on the cheap. The neighbor has given up on the idea of a pond because he is into it for over 30K already.
 
   / leaky farm pond
  • Thread Starter
#4  
Had never considered the NRCS issue....geeze...but thank you for that heads-up.
 
   / leaky farm pond
  • Thread Starter
#5  
Interesting problem. My neighbor has a similar issue. He spend a great deal of money excavating, what is basically fractured basalt, over a layer of sandstone. The neighbor, who shall remain nameless, has a habit of hiring idiot contractors. The excavators went right through the sandstone layer. So its fractured basalt, in clay, and a bottom that went through the sandstone layer. I got asked to look at it, cause it wasn't holding any water. An EPDM-rubber liner was out cause that was too expensive, so I suggested Gunite. He again hired an idiot that had no idea what they were doing and the Gunite mix was wrong and the liner just deteriorated into a mess of chicken wire and aggregate. Since then I have suggested an infusion of a clay slurry with fine wood chippings and work it up till it holds water. He has very fine clay available on property and a chipper and a wood lot. So I think you are on the right track with the clay idea. You are looking for a way to plug this on the cheap. The neighbor has given up on the idea of a pond because he is into it for over 30K already.

I have to admit, I have hired my share of idiot contractors! That is exceptionally easy to do. I appreciate the idea of adding wood chips to the clay slurry...sort of sounds like building an adobe layer?
 
   / leaky farm pond #6  
Interesting idea of slurry and wood chips. Would you please expand on that? How is the slurry mixed (cement mixer?) and then applied? Reminds me of the pigs and straw system used in Eastern Europe. Thanks
 
   / leaky farm pond #7  
...then it slowly subsided to about 1 foot deep over the next month or so. It never seems to get any lower than that so it appears not to be leaking in the very bottom. There are trees up to 8" in diameter growing within a few feet up the bank from the 1-2' water level. Poking around while removing some trees I could reach with the backhoe, I found traces of what looks like bentonite, suggesting that the pond has never held water, despite being 15-20 years old, and some half-hearted efforts to seal it up. I have looked carefully for evidence of leaks through the bank and found none. There is no stream below the dam, even right after a pond-filling downpour, so the water must just be draining through the rocky soil. Our soil looks redish, suggesting clay, but it is filled with gravel and quite crumbly.

Two things could be happening here. One, the water drains down to the natural table level of a spring that's under your pond. A spring can be good if it drains into a pond, or it could be very bad if your table level rises and lowers, or even worse, it's always at that low one foot level. Water comes and and out of a spring equally.

If it's not a spring, the next most obvious issue is the crumbly nature of your soil. Nothing can be added to fix this, or change it. Betonite is a super expansive type of clay that when wet, gets bigger and helps in poor clay conditions, but wont do anything for crumbly type soil Don't waste your money on Betonite.

Clay will hold together in your hand after you squeeze it tight. It will also hold it shape. Easy test is to try to make a bowl out of it and then add water to the inside of the bowl. If it holds water, you have good clay. There are dozens of different types of clay out there, some are not as good as others.

Just off of what you have said, you have two solutions to fixing this pond. Both start out with getting it dry and cleaned out of any silt and muck. You will probably have to wait until late summer to do this. Then you can have good quality clay brought in, spread and compacted. The clay needs to be two feet thick, over the entire pond. A dozer is good for spreading, but horrible for compacting. A sheepsfoot roller is the ideal tool for compacting clay. On smaller areas, I use the front tires of my backhoe with a full load of dirt in the bucket, and just keep going over the soil until it's rock hard.

The other option is to buy a liner.

Do not waste your time with any other type of repair. While some people might say that something worked for them, or they heard of it working for somebody else, you do not know what they where trying to fix. Their repair has nothing to do with your crumbly soil. You are in something similar to sand, and even though it's not sand, that's what you need to treat it as.

Tree roots will lead to leaks, but nowhere near as fast as what you are dealing with. If the tree dies, the roots decay, and over time the roots rot and create a path for water to flow out of the pond. The other issue with trees is that some animals dig tunnels along them. This is only an issue on the dam. Beavers also cause damage to dams because they tunnel into them and weaken the dame. But that's getting into another set of issues that are not related to your soil issues.

And if you do not like or want to pay for what it costs to fix the pond, filling it in is probably your best option. It's fairly common and it will end a never ending headache.
 
   / leaky farm pond
  • Thread Starter
#8  
Two things could be happening here. One, the water drains down to the natural table level of a spring that's under your pond. A spring can be good if it drains into a pond, or it could be very bad if your table level rises and lowers, or even worse, it's always at that low one foot level. Water comes and and out of a spring equally.

If it's not a spring, the next most obvious issue is the crumbly nature of your soil. Nothing can be added to fix this, or change it. Betonite is a super expansive type of clay that when wet, gets bigger and helps in poor clay conditions, but wont do anything for crumbly type soil Don't waste your money on Betonite.

Clay will hold together in your hand after you squeeze it tight. It will also hold it shape. Easy test is to try to make a bowl out of it and then add water to the inside of the bowl. If it holds water, you have good clay. There are dozens of different types of clay out there, some are not as good as others.

Just off of what you have said, you have two solutions to fixing this pond. Both start out with getting it dry and cleaned out of any silt and muck. You will probably have to wait until late summer to do this. Then you can have good quality clay brought in, spread and compacted. The clay needs to be two feet thick, over the entire pond. A dozer is good for spreading, but horrible for compacting. A sheepsfoot roller is the ideal tool for compacting clay. On smaller areas, I use the front tires of my backhoe with a full load of dirt in the bucket, and just keep going over the soil until it's rock hard.

The other option is to buy a liner.

Do not waste your time with any other type of repair. While some people might say that something worked for them, or they heard of it working for somebody else, you do not know what they where trying to fix. Their repair has nothing to do with your crumbly soil. You are in something similar to sand, and even though it's not sand, that's what you need to treat it as.

Tree roots will lead to leaks, but nowhere near as fast as what you are dealing with. If the tree dies, the roots decay, and over time the roots rot and create a path for water to flow out of the pond. The other issue with trees is that some animals dig tunnels along them. This is only an issue on the dam. Beavers also cause damage to dams because they tunnel into them and weaken the dame. But that's getting into another set of issues that are not related to your soil issues.

And if you do not like or want to pay for what it costs to fix the pond, filling it in is probably your best option. It's fairly common and it will end a never ending headache.

Sounds like wonderful advice. I will try the bowl test and see how bad my problem is after that. Thank you.
 
   / leaky farm pond
  • Thread Starter
#9  
Sounds like wonderful advice. I will try the bowl test and see how bad my problem is after that. Thank you.

Well, I handled some of the material near the water's edge, and it clearly has quite a bit of clay in it, as it clumps pretty well and is quite sticky. What I also noticed is that there is a ton of gravel and small stones mixed in with the clay. It could be that the material is not in a thick enough layer to seal well, and/or that the mixture is not compacted enough to seal? I pitched the fill it in idea to my partner, but she said no. As long as there is even a little water in the pond it is better to have it than not. When it gets hot and dry, if we still own the place, I may try and work on mixing and compacting the bottom, as well as digging down to see what it looks like in depth.
 
   / leaky farm pond #10  
When I dug my big pond, I hit an area of sand that was probably about a thousand square feet. I dug it out several feet to where I couldn't find any more sign of it along the edges, and then filled the hole with re clay from other parts of the pond bottom. All it takes is a small area for the water to leak out, but the only way to know where it is and how big it is will be to start digging and examining the material that comes out.
 
 
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