Pond Boss Forums INTRO Questions & Observations GA 10 acre pond/hole, 2 years and still notf full? possible dam leak? (new pics)

A lot of dams are built in the SE where good clay exists without a core trench. If the soils are not permeable and there are no rock or sand features that could result in seepage under the dam and the dam is designed so that its weight is stronger than the water force then many do not include a core trench. But it is critical that all seams are such that no water gets between the dam bottom and the underlying clay soil base or the entire dam can move/slide.

My question is does the pond leak or not. Like Brettski that tree looks like trouble to me. There is only so much we can do from pics. If there is concern that the dam was not constructed right to impound this amount of water then an engineer should look at the dam. If not then slowly fill the pond and watch for leaks. I noticed in several pics. standing water outside the pond. I assume this was from rain and not a leak.

I somewhat agree with PF2.

We don't seem to know why the grandfather shut off the pumps.

Dampness below the damn could be due to several factors, some not associated with a leak.

I don't want to underestimate the potential dangers if the pond fills and then the dam gives way, but other than that, I would turn the pumps back on and see what happens.

cancel the BS Jamboree in the field behind it...JIC

With my land being as flat as it is, dam building is probably not part of the pond equation for me but I appreciate the education Hillbilly.

I would never even consider core trenching a
dam where good clay soils are present. Why
remove already compacted clay and fill with
clay that needs compaction. However, I would
insist on removing all top soil and weathering,
and compact along the dam center line all the
way up to permanent water line. Most seepage occurs through the first few feet below the
water line.

When in doubt, I try to lean back to the fundamentals...and I usually get those from Pub 590 and then move on with practical experience from those around me (that would be you's guys).
Pub 590 does plainly state that "the most satisfactory foundation consists of soil underlain at a shallow depth by a thick layer of relatively impervious consolidated clay or sandy clay. If a suitable layer is at or near the surface, no special measures are needed except removing the topsoil and scarifying or disking to provide a bond with material in the dam. (it goes on a little later to say) If the dam's foundation is overlain by alluvial deposits of pervious sands and gravels at or near the surface and rock or clay at a greater depth, seepage in the pervious stratum must be reduced to prevent possible failure of the dam by piping. To prevent excessive seepage, you need a cutoff to join the impervious stratum in the foundation with the base of the dam. The most common kind of cutoff is made of compacted clayey material. A trench is excavated along the centerline of the dam deep enough to extend well into the impervious layer (it goes on to describe the coring procedures)."
I will add that Bob Lusk, in a recent post, concurs with the notion that a core is not required where the foundation soils are impervious to suitable depth. So, to me, the question remains: a) is there a core? b) regardless of "a", are the soils impervious to suitable depth? c) assuming that a & b are fine and non-factors, will the mass hold back the volume of water/pressure when it is running at emergency spillway levels?
(excellent debate, gents)

Brettski,

No doubt, sometimes a key and core trench are essential. I just hate to see people spend a lot of money on a core trench if they don't need to. It costs a lot of money to excavate and refill a trench, sometimes as much as the dam on top of it.

I doubt that tree grew in only two years. Looks like the contractors pushed the dam up to the tree and it is dead now.

bhb- how is the pond maintaing the current level is the main question. Natural runoff?

ill have to look into getting the dimensions of the dam but i think its at least 10ft to the water level. im also not sure about total acreage/feet etc. i know we had some surveyors out here once, so ill see if i can get the data. there is no drainage of any kind. im also thinking there should be zero watershed, other than the acreage of the pond itself. the pond was constructed on what i think is the highest point in the county so i dont think theyll be much rainfall coming in.
pondsforfun, what you said is pretty much right. and thats what ive been thinking the entire time. its maintained that level for over a year now. so something is right. im just concerned that when its full, something might be wrong like the dam not strong enough. that one dead tree in the pictures bothers me and i have no idea why it wasnt removed. i had the NRCS out here today and they didnt have great news, they said that all around the pond is great soil for ponds, but the pond itself is "Tifton" type soil and doesnt hold water that well. they were not that informative though, they never got of the truck to take measurements or anything. so i think i might have them take some samples. other than that im not exactly sure what to do. i need to calculate how much eletricity/time it will take my well(450gpm) to fill the pond. and i have to figure out how much water it will take to maintain a certain level if there is some leakage in the basin, but thats after i insure the dam wont break flood the trailer thats a couple hundred yards behind it.

So....
to feel better about the dam itself, could one take soil borings just outside the dam...maybe every 100-200 ft along it's periphery? Run these test holes right into the grade to sample the soil that is supporting the dam that sits some 20 - 30 feet away...? The damn tree (ironic, eh?)...anyway, the damn tree is still a tiny thorn because of the roots, right?
Regarding soils, the NRCS office can easily provide soils maps of your area and immediately surrounding. They can also provide tons of engineering info specific to each soil type. I find alot of this stuff on-line. It is usually within the USDA category of your offical State website. It takes alot of drilling to find it; add it to your favorites when you do.

How could they tell anything from the truck? That may be the best pond for holding water in the country with no water coming in and it kept it's level for a year?

Uh-oh! Now we hear the rest of the story. You only have three choices. (1) Move the trailer (2)Hire a good dam engineer at great expence. (3) That pond doesn't look so bad. With the proper stocking it would make a good fishing pond just where the level is now. :rolleyes:

well i finally caught my grandad at a good time today and he took me to where the he saw standing water. ive attached the pictures, but there was water coming out of two spots about a 100 yards behind the dam. its rained here recently, raising the pond level, so i could tell where the water was coming from in the ground. now how do find out where these leaks are coming from if they are that far away from the dam?
i also asked him (i spoke with my uncle before) about a core trench and he said one was dug. he said that before the dam was constructed, an excuvator dug out where the dam was going to be and filled with clay. he didnt know how deep he just said deep enough that the excuvator wasnt visable anymore. and about the dead tree, he said that all the roots were removed and that we could remove it if we need to. i talked with him about the what the soil guys said and he said that theyve said that before about the ponds hes built, one right next to it and one a couple hundred yards away, and theyve both held water. so hes not worried about that, just the leaks. i plan to move some more dirt to where that dead tree is after we move it. but the leaks im not sure about. the dam seems like it has the right slope, around 2:1, water side. and seems to be designed right? what should i do?

I don't think the leak is any danger to your dam. If the water is seeping into the basin and somewhere below the dam then the best place to try to stop it is the basin. In my opinion, and if it were my pond, I'd drain it down at least 4-5 ft below where it is now, disk it deep and compact with a sheepsfoot. Unless you want to spend a pile of money, that's your best bet. I'd look for some type of change in the dirt along the level of the leak. Maybe you have a seam of extra sandy clay there somewhere. If something looks suspect, push a pile of clay over it. Your 'Tifton" susoil is a somewhat sandy clay, right?

bhb,
If you and your Grandpa have enough evidence to feel certain that the water you are seeing is directly related to hydraulic activity from within the pondsite, you may, indeed, be at a point of need for a certified engineer's on-site review and advice. There are alot of very smart dirt-guys on this forum and I suspect that you will get a number of great ideas...it may make your head spin. Sure sounds like the NRCS has limited interest in truly participating...? Personally, any further input from me would only be throwing darts...I won't go there. The only thing I maintain is to "bone up" on the soils in your area, as mentioned in prev. post. Past that, I become a passenger on your ride until I think I can interject something useful.

edit: RE; NRCS involvelment. It occurs to me that, in my neck of the woods, the NRCS will not get involved in pond projects that exceed 50 Ac/ft...might explain their posture?

I don't know Brettski. I think you worry too much. I'd pack it and fill it gradually.

TN H
Like I said...I ain't a dirt-guy.
My concern is directed to efficient use of time and money The way I see it, if the specific cure is lower the water, pack it, and fill it gradually, then you are absoulutely correct and it should be done...finito. If this prescription is an educated guess, what happens if it doesn't help or work? Who is gonna cover the time and expense to go back to the drawing board? A 10 acre lake is a substantial undertaking...I would do everything in my power to try to get it right the first time, including consideration of paying for professional engineering advice. I don't know about anybody else, but knowing that there is running water 100 yards behind a dam that it eminated from is beyond me. I would want a trusted, professional source that eats/drinks/sleeps this stuff to tell me to not worry.
(I offer this response will all due respect)

To me all the evidence points to a seep thru the basin soil. Compaction is the most effective remedy, bar none, and by far the cheapest. He has clay, it just isn't sealing itself, it needs a little help. They may have dug a little deep and gotten into some sandy clay, pack it. If bhb1034 is a do-it-yourselfer, he could probably rent a self propelled sheepsfoot compactor and do the entire job in a 3 or 4 day weekend for $1500.

sorry i havent replied in a while. i really do appreciate the help and advice. ok so from what you guys are saying, im thinking i should contact an engineer to look at the pond. where do i find one, what listings are they usely under? i already plan to drain the pond, move some dirt and create some structure. i would like to do this all myself, we have access to a lot of equipment here on the farm. but ill have to rent the sheepsfoot compactor. and it will be around $1500 for a couple days? ive never rented heavy equipment before so i didnt think it would be that much. are these readily available at most equipment rentals? im sure its ideal to pack the entire basin, but im not sure yet how low ill be able to draw it down. would not packing the deepest sections make the entire project pointless? but other than the plans i have now, is the anything else i should look into doing? thanks again

I'm not sure what it would cost you to rent for a couple of days. I'd think that a self propelled compactor would run you at least $1000 for 3-4 days including delivery, they are pretty big machines. I'm sure you could rent a draw type if you have something to pull it with much cheaper. Best thing to do is find a local excavator who has one and see if you could rent from him. They generally only use them a small part of the time. Looks to me like the deepest parts of the pond are holding water. But if you drain it all the way I'd go on and pack every square inch I could. Good luck.

the one thing im not really sure about is finding an engineer or expert to inspect the dam to make sure its built properly. is there engineers that do private consulting, or those that specialize in ponds? do most cities/counties have an engineer that would come out? or should i look for a pond building companies on-site advice? i guess im just wondering where to find a real expert on pond dams.

the bhb dilemna: I'm just guessin' here, but I gotta think that this question is at the top of the "Pond builder's FAQ". I'm pretty new to this entire pond thang and this forum, but it seems that most all the questions regarding empbankment pond construction are no more than 2 points away from this query.
So, has anybody come up with the Certified Pond Builder's Yellow pages yet? I have read mostly good reports of "doin' the best I could with what I found" as pond projects proceeded, but there were a couple of negative feebacks. My first thread 5 months ago revealed an unfortunate "contractor revolving door" with Ahvatsa; I think he went thru 3 guys and big bux to find #3.
Guys like TN H are lucky; they have the dirt savvy and equipment knowledge to take and make decisions...right or wrong (mostly right I presume ). Even bhb has some heavy equipment training. But, like Goliath, all the muscle in the world won't overcome one good slingshot full of hidden seepage.
I, for one, found a good guy for my project. It took research with the locals and a little interviewing. I boned up on the fundamentals of my type project and then listened to see who would "talk the talk, walk the walk". I nailed it on the second interview.

Has anyone here tried ESS-13? They advertise in Pond Boss and the seepage here is well below their maximum. www.seepagecontrol.com


bhb- With a good keyway in the dam I would only worry about the seepage. I think the dam was well designed and built. I agree with TNHillbilly. The seepage is a porous sand or limestone that is slowly letting water seep out of the pond.

bhb,
Just as you have turned to the PB forum for input and ideas, you need to do the same from right at home. Everyone here wants to see you get it rite the first time, no less yourself. The dirt cures offered here are intelligent and make perfect sense, but you need somebody on-site that is familiar with your turf to "look over your shoulder" and bolster these good prescriptions. So, as you mentioned: who, where, and how do I find them?
When I recently spent 3 or 4 years looking for the right pond property to develop, when I found something that peaked my interest to the level of "pond-ability", I always reached out to the NRCS for help. Granted, your initial dance was cold at best, but that may have been because of the size of your project...too big for their interest...? I would not relent on squeezing something out of them to help in your quest. Anyway, whenever I got serious about a pond property, the NRCS in my region was v helpful and always maintained a list of recommended contractors that they had worked with successfully in the past. I think you should go back to them and continue dialogue. If you are totally unhappy with the response, it isn't against the rules to reach out to the next county and do the same.
If you can get a couple of recommended dirt-guys with referrals of local success, I would get them out there to look it over on the basis of a possible bid to do the work. Use what you have learned and pick their brains. Nobody says that you have to hire any one of 'em....but...who knows...you may.

Just measure the dam out for yourself. Sometimes folks try to make this way more complicated than it really is. If it's 10-12 ft wide on top and has at least a 2:1 slope on each side (3:1 if you have plenty of money and dirt) and there are no obvious leaks thru the dam then you'll be fine. Quite simply, that much water pressure can't move that much dirt all at once. So if your dam is 10 ft tall, and 12 ft wide at the top, it should be at least 52 ft wide at the bottom. Just make sure you have your overflow structures in place before you pack the basin. The number one cause of pond leaks is improper compaction, either during the dam building, or, depending on the soil, failure to compact the basin. If you research holding ponds for livestock waste, you'll see that they are always packed with a compactor, never with a track machine, regulations require it. If your soil has at least 25-30% clay, there is no reason you can't build a pond to hold water.

oh that reminds me of another thing my grandfather said when i asked him about an overflow. he said we didnt need one, that if it ever rained that much or was about to overflow we'd take the backhoe and make a temporary overflow on one of the sides. this sounds dangerous to me, but i doubt it will ever rain enough to overflow it, theres no runoff going into the pond. so what do you guys think of that?