About 4 years ago, I purchased my Grandfathers old homestead. He had a few ponds on the property, one for watering livestock, and one for ducks, geese etc that he hatched and raised....hundreds of them. I filled in the live stock pond and decided to expand the water fowl pond. It was a round pond, fed with run off approximately 8' deep at the dam, and about 1/2 acre surface area.
My Grandfather passed in 1997, the property owner basically let everything go before I was able to get it back into the family (My father and aunt grew up there and the property had been in the family since the early 40's). Due to the lack of maintenance, everything, and I mean everything had to come down. House, barns, outbuildings, etc. The tree's were so thick on the property and around the ponds that they were barely visible.
I purchased a Case Construction King backhoe and a John Deere 650 dozer. My other grandfather was a retired operator, and although I am a novice, I have operated a wide variety of equipment. I wanted to expand the pond. I cleared the property and began the expansion. The soil for the pond is all timber clay, hardly any dirt at all. One of my early mistakes was utilizing the existing dam, I should have started over, but hindsight is 20/20. We hauled in another 350 tons of good clay to raise the dam to the level needed. The base of the dam is approximately 80' wide and about 20' at the top. The deep end of the new pond would be at the dam, and it would be 20' to 22'. When it was all done, the pond filled and it was awesome! Fish were stocked and everything seemed good to go.
Fast forward 6 weeks, I have a road that goes behind the pond down to the river. I was on my side by side about 50' away from the dam and it sunk to the frame. The pond was leaking and I fought it for two years with no luck of it sealing. We had a hard winter that year, the pond drained to a depth of around 10' and all of the fish winter killed. Last summer we drained it and found gray shale about 1' below the clay floor of the pond in the deep end. Although we didn't find anywhere obvious where the leak was, it was decided that we would do another 3/4 acre expansion, use the clay out of the expansion to pack on the floor and the water side of the dam.
This is the summer I have to get this done. I have a few questions in regards to my plan. 1st, the pond will be dry, it is currently fed by run off, and I am hoping for a dry summer so that there isn't a lot of pumping involved.
I've thought that maybe I should go along the face of the dam and possibly dig a new key, then add to the face of the dam. I'm not sure if there is any value in doing this.
Before I allow the pond to begin filling, would it be beneficial to look into bentonite, or some other form of sealing agent?
Lastly, on the shallow, intake side of the pond, I have an old well that sits about 15' from the shore. My father and I have discussed from the beginning of the build of digging the well out and attempting to have the spring help feed the pond. I'm not sure if this will work, but I know that it is a healthy spring that feeds the well. I also know that there are vast amount of veins that run through the property. The well, as well as the pond, lye in a valley and the ground is always soft and wet. The well depth is 28' and has around 15' to 18' of water in it. The problems I see is that the pond depth on that end is only 5'. If I had a 15' or 18' hole on that end of the pond, would there be an issue where the pond would drain through the spring? I figure that the hydraulic pressure wouldn't be as great at the shallow end, the valley from the intake to the over flow in the dam has about a 10' decline in elevation towards the dam.
Any help you guys can provide would be great. I don't want to go through this again. It has been disappointing to say the least. Sorry for the long post, but I wanted to attempt to provide you guys with as much information as possible! Thanks in advance for your opinions!
I would do it over from scratch Take it from experience If you have the equipment it's only going to cost you time and fuel Definitely put a proper core in and compact bottom and sides
With my pond after a whole host of possible solutions ( re- coring the dam in the front, re- coring the dam in the back, adding benotinite then polymer You name it I've done it. i'm not sure which one helped the most but it seems to be holding up now
Someone suggested something interesting to me, and in hind sight it makes sense Everyone makes the dam side the deepest part of the pond ....that's where you are most susceptible to leaks and failure. He said that I should have made the opposite side deeper and the dam side shallow
You definitely are on the right track asking questions here I'm sure you will get the correct answers
Cut new key. Compact pond bottom with sheepsfoot roller in 6" lifts, knitting the layers together - don't use the tracks on the equipment, they are made to lower the ground pressure and "float" the equipment.
A spring or well flows water both ways, depending on the pressure of the water in the ground. If it was mine, I would completely compact the whole pond bottom and sides, up above the high water level. Key the dam, make primary and secondary spillways.
Compact pond bottom with sheepsfoot roller in 6" lifts, knitting the layers together - don't use the tracks on the equipment, they are made to lower the ground pressure and "float" the equipment.
That was my problem, and why my pond leaks, despite excellent clay. I was not yet on Pond Boss, and let the dirt guy, who has built many ponds in this area, do it as he wanted. He used the bulldozer to "walk in" the entire pond bottom. If I had him use his backhoe with loader full of clay to do it instead, the compaction would have been better. A sheepsfoot roller cannot be had as a rental in this area, and only the large road construction companies have them. Hopefully, with some big rains, I will eventually get some clay settlement. Most ponds in this area eventually do seal.
Someone suggested something interesting to me, and in hind sight it makes sense Everyone makes the dam side the deepest part of the pond ....that's where you are most susceptible to leaks and failure. He said that I should have made the opposite side deeper and the dam side shallow
Best of luck
That would work pretty good if using a scraper to move most of the dirt. A lot of ponds, especially smaller ones, a bulldozer is the only tool and if a dozer is doing the dirt work, the shorter the push the less cost. That is why the deep water is near the dam on a lot of ponds. Shortest distance for the dozer to move the dirt.
Using a scraper moving more of the dirt from the far side of the dam would not be a bad deal at all if a person was using the loaded rubber tire scraper for the compaction tool. The longer dirt haul could be combined with the compaction phase.
Dozers are not worth a darn to move dirt any distance.
If the whole pond is plated and compacted with clay in layers, is there any need for recoring the dam? I was always under the impression that the main reason for keyway is so that the piled dirt will not shift once pressuure is against it. A side benefit is that it helps seal off water. Sure water will leak thru if you just start pillng dirt onto topsoil/previous compacted dirt without it's removal, but even worse the dam will slide on that topsoil and blowout. To guarantee the best leak proof pond is to plate/seal the ENTIRE basin.
My thought is if the dam is solid enough to have held up for these years, AND if the rest of the pond is going to be re-sealed with clay, it might be easier to just seal it up to water level on the dam too. I would think that this would seal any possible leak better than recoring. With recoring and the possibility of springs, there still may be an area that works around the recore. By plateing everything, once the water is in the basin, it's more of a guarantee to be leak free.
There has been a few threads on here where a dam is recored to stop a leak, only to not accomplish the goal. Springs "can" work around the keys, no matter how deep or how long they are. Lots depend on soil materials, but it sounds like this pond is in an area that has springs.
That sounds logical to me fish n chips. If the dam is "physically sound" and you cover the basin with clay even up the front of the dam, the clay should act like a bowl or rubber liner. The dam is just there to hold the clay bowl in place.
The down side to doing it that way would be that it would make the pond slightly smaller as the dam at water level would be thicker by the depth of the bowl material. Only likely a problem if the real-estate for the pond is very limited. Otherwise an equivalent amount of size could be added to the opposite side. Probably splitting hairs on this point.
A person could even use the clay bowl to be part of an erosion "bench" along the dam. My dam has an erosion bench to prevent wave erosion.
