Hello, I’m a complete newbie for anything to do with a pond and at a loss as to where to make my first steps on a small pond in the woods in New Hampshire. The property we bought is an off grid cabin and the pond, we were told, had a liner installed that got mucked up by a moose and then basically just fell apart. The previous owner put in the pond and held the property for about 40 years. He was only at the cabin once or twice a year if that, so I’ve been focused mostly on trying to see if the cabin was salvageable, but now that spring is here and the ice on the pond has melted, the bunched up liner is really becoming something I feel like I need to deal with. The owner told us this is a ‘table water’ pond. It gets run off from the mountain and goes over some concrete edges and into a nice stream down the hill. It’s really spectacular aside from the visible plastic liner bunched up and sticking up above the surface. But I’ve not seen a forest pond quite like it and am wondering if that’s because a pond with trees growing all around the edges and moose going for a swim, etc, doesn’t make for a stable pond!
I’d like to do as much as I can on my own, cutting back trees, getting in the pond and cutting out the liner, etc, as possible since we don’t have a ton of cash to spend and this place is actually behind a forest service gate and down a logging road and then down a driveway that is pretty tight.
As much as I’d love a swimming pond or a pond stocked with fish, my guess is I’ll need to settle for a frog pond, and I’ll be okay with that if I can get rid of that liner.
I’ll do my best to attach pictures once I figure out how. I will say the size of the pond has changed drastically since winter, when it was up to the tree line and we could ice skate on it. It’s dropping pretty rapidly now, but maybe that’s normal for a table water pond with a broken liner in it?
Sounds like a wonderful place. The pictures part is pretty easy....there's an attachment manager that you can drag files into but the pics have to be 2meg or less. Might have to crop them down to hit the 2meg size.
Pics would probably help a couple of the more experienced fellas give some tips on the liner.
Personally, I can't make much sense of what the previous owner told you. If they truly had no clue what they were doing, then perhaps you can fix things for a reasonable price.
In general, there are two types of ponds: a surface water pond or a groundwater pond. (A groundwater pond is also sometimes called a "water table" pond.)
Rainfall on sloped ground will start to run to the low areas, and continue to aggregate until it eventually forms a creek or stream. If you dig a little hole and dam a low area in a system like that, then you have created a surface water pond. Your description of your situation sounds like a surface water pond.
If you filled your bathtub with three feet of sand and then added some water, that would be similar to a groundwater pond. If you added only 1 foot of water, then the water table would be two feet below the top of the sand. If you dug down three feet to the bottom of the tub, then you would have a groundwater pond that was 1 foot deep. If you added another foot of water, then the water table would move up, and you would then have a pond that was two feet deep. Generally, a groundwater pond will rise during the wet season, and then the water level will go down in the pond during the dry season.
I don't quite understand your description of "concrete edges". Sometimes the land above a pond will be modified to help direct run off into the pond. Any chance there are terraces, berms, concrete ledges, etc. that help direct some of the run off down the side of the mountain and into your pond? If so, then that helps confirm that you actually have a surface water pond. Also, I believe it is much more common to use a pond liner for a surface water pond.
When your pond was full over the winter for ice skating, was there some water continuously running down the mountain and into your pond? If the drain in your bathtub was open, but you had five taps running full blast, then your tub would overflow. However, if the water supply to your pond continued to be reduced during the spring, that would be like turning off the taps. Eventually, when the water supply into the bathtub was less than the water outflow down the drain, then the water level in the bathtub would start to fall.
I know that is a lot of words, but you are the only person with actual eyeballs on your situation. Does that sound like that might be what is happening at your property? If so, then I think there is an excellent chance that you have a surface water pond with a leaking pond liner.
Can you give an estimate of the size of the pond? Even just X feet long by Y feet wide. Or a rough circle with a diameter of X feet. Also, how deep was the pond when it was full?
Finally, is there any kind of pipe or structure to let water OUT of the pond when too much water is coming in?
A properly installed liner is actually anchored into a trench around the outside of the pond. The fact that the liner appears bunched up, makes it sound to me like there is a chance that it was NOT correctly installed? Can you see any cuts in the liner made by moose hooves? (They might just look like crescent lines in the liner material.)
I am NOT a liner expert, but we do have some on the forum that can give you some good advice after you have fully evaluated the extent of the problem. Holes in a liner can be patched. The modern liner material is designed to be patched and seamed.
If your pond is big enough to skate on, then it will actually be the WEIGHT of the liner that causes the most difficulties for you to repair. Do you have some very hefty family members that might be available? If not, then you probably need heavy equipment - and that probably would then require expert operators. If the liner itself is still in good shape, then you might be able to hire some installers to do it right this time.
Almost everything I said above is very speculative. However, I was trying to throw out lots of ideas to help you think about what your are actually observing on your property.
Okay, think I shrunk the pictures down enough to attach and show everyone the horrific pics I found from last fall when the water emptied out and you could really see the crinkled mess of a liner.
And I think maybe those concrete edges were just for walkways over the overflow?
These first few pics are last month when the water was still high from winter. I’m horrible at guessing sizes, but I’m wondering if the two dogs in the pic could be used to judge the scale? I know that’s ridiculous, but quite likely a better estimate generator than myself!
There are a couple pics of the culverts that bring water in and a couple pics of the overflows where the concrete is. And then the last shot is from the runoff stream, looking back up at the overflow and pond. I’ll do another post with the pics of how bad it gets when the water drains.
The first ones are from last late fall when it was really low. The last one is recent, and kinda an idea of where it is now in the progression of drying out. I think it will get even lower this year than it was last fall since last year was very rainy all summer.
I was thinking my first move would be to cut back all the brush and any saplings up to maybe 3 inches in diameter or so? And clear all growth and everything from the culverts? And then maybe see how hard it is to cut chunks of the liner up and how heavy they are to pull ashore, probably around august-autumn when it’s at the lowest.
Can’t agree on cutting the brush and saplings. They will most likely come back from the roots. I would poison them and then clear. They are water suckers.
I have zero experience with liners.However, I expect the whole thing needs to be drained and a new liner installed.
It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.
Without a sense of urgency, Nothing ever gets done.
Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP
I wonder if I could remove the liner this year and then put bentonite in it next year. It seems like that would maybe hold up to wildlife better?
Your gut is correct. Cut ALL the saplings and trees. Paint the cut stumps with Tordon RTU when you cut them, IF you can buy it up there. If that isn't available, ask around what to put on cut trees so they don't grow back.
You just can't sprinkle bentonite on the ground, it has to be incorporated into the soil and the soil packed down. It will help to get the liner out of there in smaller pieces but here's an idea.
I don't know how easy it is to get a skid steer or small excavator in there. It has to be doable somehow because that's what was needed to get the liner in there in the first place. Pull out and save as much of the liner as possible. Call BT Liner 1-541-447-0712 See if a 1 piece liner will fit the budget. You can use Google Earth Pro to map the pond. Or PM me the GPS coordinates and I can map it for you. You can use the old liner pieces as underlayment over any rocks for the new liner. Like a carpet pad of sorts.
BT Liners makes pretty tough liners, but the correct way to install it is to dig the pond deeper 12" deeper than finished size, spread out the liner, and cover it with 12" dirt. That way a moose will have a hard time reaching the liner if it walks into the pond.
I am no liner expert, but that does NOT look like moose damage to me. It looks like an improperly installed liner!
(Don't know your exact pond size, but that is WAY too big for family members to fix by hand. Will need some equipment and pros, if fixing. You can cut out and remove in small pieces by yourself. However, don't be hasty on the decisions, that liner was pretty expensive when new.)
More importantly, when the water level was high this winter, was water running through the rocks under the stone walkway? It looks like it in the pics. An 8' wide berm of cobble stones can back up water when there is a lot of water flowing into the pond. However, it cannot possibly "seal" a pond without other features in the berm. That area right there might be your leak. It also looks like there may be other areas of the "dam" around the pond that are also composed primarily of rock?
Is the culvert pic water running into the pond, or out of the pond?
I wonder if I could remove the liner this year and then put bentonite in it next year. It seems like that would maybe hold up to wildlife better?
Ask Dave Davidson how bentonite worked for him long term.........
Quote FishingRod "(Don't know your exact pond size, but that is WAY too big for family members to fix by hand. Will need some equipment and pros, if fixing. You can cut out and remove in small pieces by yourself. However, don't be hasty on the decisions, that liner was pretty expensive when new.)"
That's what I mean in my previous post. No matter how far off the beaten path it is, there is no way that the liner that is there could have been brought there, OR installed just by hand labor - heavy equipment had to be involved in the process.
The BTL liners are the lightest ones that I know of and they are the toughest. They make at least 4 different thicknesses. The last one that I quoted was a one piece liner that was just under 1.2 acres in size. Once all the prep work was done by heavy equipment, and the liner was on site and placed at the edge of the pond, (7,000 pounds for the lightest one) it could be unrolled and installed by a bunch of guys.
I think we could definitely get some machinery down there once we clear some room for a trailer to turn around, or maybe they could park at the entrance to the logging road and drive the machine itself to the property. So I guess I’m wondering, since we won’t be able to afford any serious work like that for several months or next year, is what I can do myself aside from clearing some of the trees. How much of the liner should I cut out and is it okay to do that and then leave those sections unlined until we can afford to do the rest. I’m going to go out to the pond later today and will get in the pond and check it out better, but I just found a ton of paperwork on it in a box the owner gave us.
The liner receipt is from the early 90s and says Griffolyn TX 2x1 D black elliptical shape 8.395 sq ft for $1804.93 71’ x 135’ Griffolyn TX 2 X 1 D black 9585 square feet for $1437.75
And there was another estimate and also a receipt for completed work (for $4500) to excavate and prepare a dam using excavated materials and two loads of crushed rock, and prepare two spillways using crushed rock, and seed the disturbed areas, along with the proposal drawings.
I can not imagine how much this would cost today, when I see all the driveway work receipts also!
And to answer FishinRod, The culverts bring water in. The water comes out of the WM National Forest so I don’t have any control over it. Looking at the owners proposed plans, the permit department cut his proposed size in half because of the wetlands. There’s a ton of water on the property too, just not sure we’d be allowed to redirect it into the pond (seems like permits for stuff like that were easier in the 90s!), and then all the water flows down to a significant brook.
If culverts are bringing water into the pond, then we know you have a surface water pond. That answers one of the original questions. (Or less likely, you may have a combination pond.)
Next important question - Is there still water running/trickling into the pond? If there is no more water running into the pond, and the water level is relatively stable, then it sounds like the bottom of the pond is sealed and you just have leaks through the crushed rock dam. This means that when you do get decent rains during the dry season, the water level in the pond should go up for a few days and then drop back down to the lowest level of the leak.
However, it also sounds like there may be adjacent wetlands. If the current water level in the pond is about the same as the water level in the adjacent wetlands, then you may have a combination surface water/groundwater pond. During the wet season, surface water fills your pond to the brim. During the dry season, the water level falls to the level of the local water table.
How deep is the pond right now in the deepest spots? There is a chance that you could stock the pond with fish and they would survive just fine even when the pond is at its lowest water level during the dry season.
What I don't like is no mention of a pond outlet system. After the thaw, when your pond was full, was there a lot of water entering the pond through the big inlet culvert? If so, there should have been an equal amount of water also running out of the pond. Was that water just running over the top of the crushed rock dam?
If you decide to remove the liner, then you can test my speculation above. The liner will be much easier to remove if you pump out the pond. If you can pump the pond dry, then you have a surface water pond. If you cannot pump the pond dry, then you have a pond that is certainly tied to the groundwater system.
You truly have a beautiful pond! Maybe just make observations during this entire year, and then decide what plan fits your pond goals and budget.
I think we could definitely get some machinery down there once we clear some room for a trailer to turn around, or maybe they could park at the entrance to the logging road and drive the machine itself to the property. So I guess I’m wondering, since we won’t be able to afford any serious work like that for several months or next year, is what I can do myself aside from clearing some of the trees. How much of the liner should I cut out and is it okay to do that and then leave those sections unlined until we can afford to do the rest. I’m going to go out to the pond later today and will get in the pond and check it out better, but I just found a ton of paperwork on it in a box the owner gave us.
The liner receipt is from the early 90s and says Griffolyn TX 2x1 D black elliptical shape 8.395 sq ft for $1804.93 71’ x 135’ Griffolyn TX 2 X 1 D black 9585 square feet for $1437.75
And there was another estimate and also a receipt for completed work (for $4500) to excavate and prepare a dam using excavated materials and two loads of crushed rock, and prepare two spillways using crushed rock, and seed the disturbed areas, along with the proposal drawings.
I can not imagine how much this would cost today, when I see all the driveway work receipts also!
So each piece is roughly 1/4 acre. I don't know why there are two pieces. To create a waterproof seal, the individual pieces need to be seamed together. They are either glued or a special heat gun is used.
Thanks for the info everyone! I think FishinRod has a wise idea with waiting a bit and seeing what happens as the summer progresses, but I also know myself and seeing that plastic liner crumbled up and over the waterline might drive me nuts enough that I cut the obviously ripped pieces out. I did go out yesterday and it was still a bit deeper than I thought, maybe 3 feet in the middle, so I didn’t make it far off shore since I didn’t have waders, but I could grab the liner and pull it out a bit. Maybe I can just pull it flat for now.
Too bad bentonite isn’t a good option, because it would be great to just not need a plastic liner because I can really see it under the water even where it lies flat. Surprised there’s not a lot more debris in the pond, but maybe it gets so dry it blows out or perhaps it gets pushed over the dam in water flushes before it has time to settle.
As for the outlet, it seems to just be over those two dams. There was a lot running over it this spring after the mountain snow melted, pretty much a stream worthy.
And as for the two liners, I think you might be right esshup, I saw another receipt that just had the cheaper option listed, so maybe he was pricing both. I’m wondering if the more expensive option is one they could shape for him and the other one he had to cut himself, which would explain the remnants I found half buried in the woods, buried under a ton of pine needles and dirt!
I truly appreciate everyone’s willingness to share their knowledge!
