Reviving an old pond...

My parents purchased a piece of property about 4 years ago and with developing tractor trails for the begining of a long road of maintenance/taming the Bush, we discovered an old pond that is obviously really old and neglected. A section(15'max width) of the dam has collapsed slightly due to a tree that was growing on the dam(was let go some years ago) and the tree I'm guessing rooted to the bottom of the dam and then a storm or just saturation of the dam due to the roots, let the tree fall over 45° ripping the roots up from bottom of dam and drained the pond. And over the years of neglect erosion has allowed more of the dam to disappear. Anyway were here to restore this pond. So at this point in time we have cleared most of the junk trees and brush off the dam so there isnt any more deep roots penetrating/weakening the dams structure. But we still have two sycamore trees @ about 30-36" diameter growing on the pond dam in a section and the 24-30" sycamore tree that's leaning 45° that actually drained the pond and busted the dam slightly. We just finished cutting all the trees that were growing in the bottom of the pond floor so we have a clean landing zone for the big monsters harvest. But once we get those outta the way its pond dam rejuvenation time. And I was wondering for sourcing the material for patching the pond dam, would the material in the bottom of the pond floor be good for patching the dam? Like if we were to dig the pond deeper, would that material be decent stuff for patching the dams injured area? I'll post pictures of the pond soon so you all see exactly what I'm talking about.

And my thoughts on the healing process for this pond dam, the area that the sycamore tree ripped up the dam a bit, I was thinking once we drop the tree, but before back filling drain area, i was thinking about putting a 8in piece of pvc pipe threw the bottom of the dam for a skimmer drain to keep pond at a certain level once its healed and full of water. But in the mean time of the healing the dam, that piece of PVC could just serve as a culvert pipe to drain water out of pond with out erosion. After a few years go by the roots should have rotted from those trees on the dam, and I should have been able to patch the dam injury in that time, I could then go to the end of that culvert/pvc pipe in the pond and add a elbow and about 8-10 foot of pipe to set the water level I want on the dam and it can drain at that level, and this pond also has a over flow channel near where the water comes into the pond so there would be over flow prevention along with the pvc skimmer drain.

Does this sound like a good plan of action to revive this old pond? If you have any other ideas please share. We dont have access to water at this property so having this pond full of water would be great for the future plans. And if I were to guess on the size of this pond I would say about 60,000-100,000 gallons. My judgement on that is me thinking that about 3-5 of my 20,000 gallon swimming pools would fit into the water holding area of the pond Haha. Idk how people measure the water holding capacity of a pond that is kinda egg/baseball infield shaped. But I do know having this much water access would be great to have on hand when clearing and doing burns, and eventually watering fruit trees and berries.

Thanks for any input,
Mike

That's a huge find, and a tremendous resource. I am envious.

If it's an earth dam, there's a good chance it was made decades ago with a bulldozer -- deepening the pond and building the dam at the same time. I think you could pretty well repeat that approach, using an excavator. However, note that it can take a very long time for fine particles like clay to settle out of the water.

Edit: Do you think the pond may face periodic flooding in large volumes? That may change your approach. Adding erosion-proof spillways, for example, and planting deep-rooted shrubs and plants on the dam to help stabilize it.

Douglas Alpenstock wrote:That's a huge find, and a tremendous resource. I am envious.

If it's an earth dam, there's a good chance it was made decades ago with a bulldozer -- deepening the pond and building the dam at the same time. I think you could pretty well repeat that approach, using an excavator. However, note that it can take a very long time for fine particles like clay to settle out of the water.

Edit: Do you think the pond may face periodic flooding in large volumes? That may change your approach. Adding erosion-proof spillways, for example, and planting deep-rooted shrubs and plants on the dam to help stabilize it.

Yes I believe your right on the bulldozer pushing this pond into shape decades ago. Unfortunately we do not have heavy equipment at this time, hope to in the future for other projects. But at this point I feel like this small of a repair on the pond dam could be tackled with our tractor with front end loader to dig material from pond floor to make it deeper and drive up and out of pond to dump each bucket load of material on the dam near the backfill area then once I have a pvc pipe(culvert) threw the dam where water is leaking out i can push dirt to back fill the blow-out area and over time the material can settle without any water pressure cuz the pvc pipe will allow the pond to drain without erosion. And after say 3-4 years after the patch has been fixed and settled in we could put the 90°elbow and 8'-10' of pipe on the pond side of the pvc culvert pipe to allow water to fill up until it reaches the flood point which I guess should be a few inches below the overflow/spillway level for the terenchuale down pours we occasionally get. I know seems like alot of scooping and driving around pond to get the material where we need it but we dont have an excavator and dont have cash to hire it out so figured we would just try fixing it with what we got. I'm just wondering if the floor material of this old of a pond would be good sealant fill material for the minor patch our pond dam needs? We probably need a total of 10tons of fill material to fix the dam, possibly 15tons for settling insurance. So that's why I believe our tractor could handle this patch, hiring an excavator to move this little of material would cost to much and not be worth it really to the operator.

I would question what materials were presently on the bottom of the bottom of the pond, ponds usually get "silted in" over time. You would want to investigate the existing dam, but I am guessing it was built out of clay. If your area is anything like mine I would wager a guess that you may need to dig though some "silt" on the pond bottom before you found the "clay" and the latter would be what you would want to use to seal your pond. The silt could be put on top of the dam after using the clay to form the watertight seal.

For your pond overflow, I would consider using a plastic double wall culvert over using normal PVC pipe. Not only are they uv stabilized and available in much larger sizes if needed, it also has ribs which should help to lock the pipe in the soil where it goes through the dam wall. Consider the area that drains into the pond, and make sure that your planned drain and overflow can handle the expected waterflow.

As an aside, In my area we have a lot of very dense clay just below the shallow topsoil. I was given some soil that was dug out of the bottom of a nearby pond, although it was clay-ish it has more organic matter and coarse particles and is not nearly as dense and lifeless as my soil. I have used that as topsoil to get grass to grow over a disturbed area of hard clay.

John Young wrote:I would question what materials were presently on the bottom of the bottom of the pond, ponds usually get "silted in" over time. You would want to investigate the existing dam, but I am guessing it was built out of clay. If your area is anything like mine I would wager a guess that you may need to dig though some "silt" on the pond bottom before you found the "clay" and the latter would be what you would want to use to seal your pond. The silt could be put on top of the dam after using the clay to form the watertight seal.

For your pond overflow, I would consider using a plastic double wall culvert over using normal PVC pipe. Not only are they uv stabilized and available in much larger sizes if needed, it also has ribs which should help to lock the pipe in the soil where it goes through the dam wall. Consider the area that drains into the pond, and make sure that your planned drain and overflow can handle the expected waterflow.

As an aside, In my area we have a lot of very dense clay just below the shallow topsoil. I was given some soil that was dug out of the bottom of a nearby pond, although it was clay-ish it has more organic matter and coarse particles and is not nearly as dense and lifeless as my soil. I have used that as topsoil to get grass to grow over a disturbed area of hard clay.

I was wondering if the silt build up would be an issue. Cuz im sure there is alot of that. Giving this ponds age, which is unknown. I mean there is two sycamore trees at about 30inch diameter and 20foot long log growing on the dam so those trees have to be close to 50 years old. Then how long had pond been dug before they let it grow up to the neglected state it's in.... this pond is probably 60plus years old and hasn't had water in it for at least 15years considering the 12-14inch trees that were cut from the floor. And I live at the bottom of illinois about 45mins from the bottom tip. And I believe we have a pretty high clay content to our soil. I guess I'll have to just test dig the bottom of pond when its dried out enough to get back out of the pond.  Where can you buy loads of high clay soil? I know a sand quarry near me sells fill dirt but it being a sand quarry I'm concerned it might have too much sand making it porous/water seaping. I know of another place selling fill dirt scraped up from an old 10acre-ish  field they just dozed the top few layers off and that spot is a low lying field(high water table area) so probabably alot of clay there... but I'm no geologist or soil scientist lol just guessing cuz they are selling it as fill dirt and the field always had a crappy crop cuz of the saturation that area gets. I dont really wanna just go digging a hole somewhere on our property for clay other then in the bottom of the pond haha.

John Young wrote:I would question what materials were presently on the bottom of the bottom of the pond, ponds usually get "silted in" over time. You would want to investigate the existing dam, but I am guessing it was built out of clay. If your area is anything like mine I would wager a guess that you may need to dig though some "silt" on the pond bottom before you found the "clay" and the latter would be what you would want to use to seal your pond. The silt could be put on top of the dam after using the clay to form the watertight seal.

Good point. On the plus side, the silt has value as organic matter for use elsewhere.

John Young wrote:
For your pond overflow, I would consider using a plastic double wall culvert over using normal PVC pipe. Not only are they uv stabilized and available in much larger sizes if needed, it also has ribs which should help to lock the pipe in the soil where it goes through the dam wall. Consider the area that drains into the pond, and make sure that your planned drain and overflow can handle the expected waterflow.

Ok now I really like this pointer you dropped here, about the corrugated culvert pipe locking into the soil better because of the ribs.

I actually have noticed this myself with little swale swivel pipe projects I have going on. The pvc took a while to actually seal because of the smooth exterior. It seemed like water was seeping along the exterior walls of the pvc threw the swale dam. After about a year it has sealed up better and I can put a swivel pipe on and hold water uphill without seepage by pvc drains' exterior walls. But I'm also not holding back much water pressure like a pond would.

So with using the corrugated double wall culvert pipes in place of pvc, how do you connect it together with water tight seals? Seems to me that the connectors to attach them together would leak if it were under water with pressure. But not sure, we connected two 8in culverts of that pipe together for a driveway culvert so that works fine. But this would be under water and under pressure. Do they make 90° fittings for that type of piping? Or would I need to use 10" culvert pipe for the horizontal pipe going threw pond dam, and the 8in culvert pipe for the vertical part skimming the water off top, and instead of a 90° (that may get clogged) just attach the 8" culvert pipe to the end/side of the 10" horizontal pipe to drop-into and then drain out that way? Is there a site that sells this pipe with fittings prefabricated in this way I have described my drain set-up? I have seen concrete fabbed drains similar to this design but that seems way expensive and i dont have the equiptment for that either.

And to the final portion of your statement. This pond has a natural overflow channel near the input, and it drains along but away from the one side of the dam(downhill side), causing no erosion to the dam but the channel it has created could use some rip-rap in a section. So I would assume that over flow is designed to the size of pond. And if this pond had been kept up and no trees growing on the dam it probably would still be full of water. But anyhow the drain system I'm talking about installing would initially help with keeping the pond empty while the dam is repaired and settled. Then after 3years or so cap off that horizontal drain pipe on inside of pond and install vertical 8in culvert to water level I want(3-6inches lower then the natural overflow channel). And then the existing natural overflow channel would be there for flood insurance when we get the toad strangling  rains that the 8in drain might not keep up with.

Again I'll have some photos soon for better idea of what/why I'm talking about what I am. If that makes sense.... Haha hopefully the photos will make sense of it all.

The plastic culverts I have used (for road crossing purposes) had gaskets, but to your point I don't know how well they would hold back several feet of water pressure. I have seen them installed at an angle through the dam wall instead of using two pieces with a 90, which wouldn't require a fitting. Those would drain to the lowest part of the lip, and should be much less likely to clog since nothing would get stuck having to turn a corner (like a stick). You could even cut the top at an angle if you wanted.

John Young wrote:The plastic culverts I have used (for road crossing purposes) had gaskets, but to your point I don't know how well they would hold back several feet of water pressure. I have seen them installed at an angle through the dam wall instead of using two pieces with a 90, which wouldn't require a fitting. Those would drain to the lowest part of the lip, and should be much less likely to clog since nothing would get stuck having to turn a corner (like a stick). You could even cut the top at an angle if you wanted.

yeah I totally know what you mean by putting it threw dam on an angle to drain. But that's when you initially build the dam. Reason for doing this drain I'm talking about is because my dam is probably 12feet tall to the flat top area. So this pond could easily be 8-10 deep. But in the area where the tree grew and compromised the dam, the tree had roots to the bottom of dam and when it tipped 45° the very bottom of pond basically had the "bathtub plug pulled out". There is a hole probably 2foot around at the base of the dam but we still have a earth bridge to cross the compromised dam flat top thanks to the trees root ball holding the soil together but the back side of the dam where the water poured out and over time has eroded a bit. This is definatly a one in a million dam failure Haha cuz its literally like a 2foot diameter tube was pressure washed out  of the bottom of dam base all the way threw, probably 20 foot long, but the back side of dam at the 10' mark of the tube is where the dam is eroding away and creating a dip in the flat top of dam there due to settling. That's why I want to put the pipe threw there before I cut the tree so then I can allow soil to settle down on pipe and backfill to make dam structurally sound without water in it then few years later turn that culvert into a drainage system so pond will hold water at the exact height I cut vertical pipe to. Sorry I haven't got any photos yet we got ice/snow on the ground and single digit temps so I'm not very motivated to get those taken just yet.

So here are some drawings of my above explanations of the pond situation...  
    First picture- the way the it looked I assume before the tree leaned over.
    Second picture- the sycamore tree that leaned over ripping its roots up causing the drain hole.
   Third picture- is the way the dam looks from standing Inside the pond and how the flat top area grade is begining to settle.
   Fourth picture- is the drain system I'm wanting to install.
   Fifth picture- is a close up of my idea of making this drain system work with the double wall culvert pipe idea.
   Sixth picture- is of how I'll set the 12" culvert threw dam initially as a drain to keep pond empty while dam settles from the repair.

And the box around that junction in picture 5 I was thinking of just setting up some forms around it once I'm to the point of holding water in pond, and pouring a 2x2x2foot cement cube around the junction sealing the 10" vertical drain pipe going threw side wall of 12"horizontal culvert and capping that end off so water flows down 10" pipe and drops down into 12" culvert to drain threw dam. Any thoughts on this idea or suggestions of similar ways to accomplish this design???

This picture is kind of a layout of the area. Labeled specific features that I thought were important to include. Hopefully these drawings make more sense of all my jumbled descriptions above...

Here are some of the real pictures of the pond. Included the problem areas as well. But overall becides the minor blowout, it's still a pretty nice pond and the dam is still in decent structural shape. This is why I dont believe we NEED a heavy piece of equiptment to fix this, and why I think our tractor with front end loader could handle this fix.

Pond pictures....

I could be wrong, but my first impression is that the hole in the dam opened up first, causing the tree to fall and lean once the dirt under it washed out. It does not look to me like the tree leaning directly caused the issue. I do almost everything with my tractor with front end loader, so I completely get trying to get this fixed yourself.

If this were my pond, I would probably want to basically dig the entire wall out at the failed section at this point. I would dig into at least both the remaining pond sides until I hit solid/sturdy material (e.g. hopefully some sort of clay). I would then figure out where on the property I could get more of that material, fill at least one vertical section in the center of the wall with that, and pack it down as best I could as I went. I would slip my new drain tile in at the same time. Then take the remaining extra dirt that was removed initially and use that to finish filling the pond dam wall. Anyway that is just my 2 cents.