Pond / Waterfall leaking

[Eric L Schultz]

Greetings,

I'm posting here because I need advice on how to fix a leak.

"Executive Summary"
I have a leak about 5 inches from the bottom of my pond. I am not able to find the hole in the rubber because I can't remove the rocks that surround more than half of the pond. I need suggestions on how to fix this leak. My current plan is to suck the water out as much as possible and inject some sort of sealant around the rocks or fill the bottom of the pond with thin concrete and hope that it flows everywhere and seals up the leak. I know enough to know that that plan is flawed, but it's all I have right now. Which is why I'm posting on this forum (and a few others).

Any suggestions are GREATLY appreciated.

"The Details"
Seven years ago I built this large waterfall feature (see the attached photos). The bottom pond is about 22 feet wide (at it's widest) and normally almost 3 feet deep. The top pond (not visible) is roughly 4' x 5' x 18" deep. There is a small area just below the top spillway that is as wide as the spillways but only a few inches deep and is mostly filled with stone. The vertical drop from the top spillway to the bottom of the bottom pond is about 13 feet. I have a 4000 GPH pump that circulates water 24/7 from the bottom pond to the top pond. I have a second pump (7,500 GPH) that circulates water from the bottom pond to that small area between the upper and lower spillways.

We used a commercially available liner under the entire EPDM rubber liner. All along the bottom of the bottom pond and up the edges I used an additional layer of rubber under the rocks to protect the liner. Most all the rocks have been stacked and sealed to the rubber using Great Stuff Foam Sealant.

Last year I noticed that I was constantly adding water to the pond, more than what I had seen previously from simple evaporation. I have had ponds for over 20 years so I knew that there were a few ways to lose water. I first turned off the waterfall to rule out water escaping over the edge of the rubber pond liner. What I found was that the top pond held the water level and the water level in the bottom pond was dropping. I filled it and watched it again but it continued to lose water at a fairly rapid pace. There was about 4 or 5 inches of water left in the bottom pond it finally stopped draining.

That told me that my leak isn't in the waterfall nor the top pond...the hole in the rubber is about 4 or 5 inches from the bottom of the bottom pond.

I began to search for the hole. Last season I climbed into the pond and moved as many rocks as I could from the edges and inspected the liner but found no holes. That left me with the disappointing realization that the hole in the rubber is somewhere on the back wall of the waterfall...behind the rocks. There is no way to remove any of those back wall rocks because they are all stacked on one another, so to remove the bottom rocks would mean completely rebuilding the waterfall which I am not going to do.

Has anyone run into a problem like this before? If so, how did you solve it?

Thank you in advance for your thoughts and any suggestions (no matter how wild and crazy).

Oh, I do not have fish or plants in this pond, I use chlorine tablets to keep it clear.

Eric

 

[mgmine]

There is nothing that can be put in the water that will stop the leak. Anything you do other than biting the bullet and pulling the rocks will be a waste of time and money and will make the job harder when you finally do pull the rocks out. With the way the rocks are stacked the water could be leaking out anywhere just like a leaky roof. The leak could be half way around the pond. Water takes the easiest route. Once you pull the rocks out I wouldn't trust a patch I'd replace the entire liner. Did you remove all the rocks that you could or just most of them? Have you drained the pond completely? If not I'd do that no telling what you may find under that 5" of water. Man, I feel your pain! It must have taken forever to build the pond. One other thing, looking at the picture it appears that you don't have one solid piece of liner. If that is the bottom pond shown I would suspect that area might be the problem

 

[Eric L Schultz]

Thank you for your reply!

I have drained it completely using a shop vac to get the last of the water out. However the water that is trapped between the liner and the clay seeps back in. I did pull all the rocks along the right and left edges as far around as I could. Any further around and I would've been compromising the stacked rocks above. That extra rubber under the rocks is the double layer, the entire bottom pond is one piece of rubber.

Regarding the thought of removing and rebuilding the waterfall...It took my wife and I, with help from my son and son-in-law, six months of body breaking work to build that sucker. I just don't see it happening now that I'm older.

I've thought about injecting some sort of sealant between the rubber and the clay in hopes of sealing it, but I realize that it is a long shot at best because whatever I would inject would mix with the clay and mud and probably not work anyway...

 

[mgmine]

What a shame it's a beautiful pond. I can't think of anything that can be squeezed in the will solve the problem. If you had a leaky pipe that might work but not something like you're dealing with. If you shut it down completely and let all the water settle out of the rocks and keep it dry then you may be able to find the approximate spot where the water is coming from by watching any place that keeps getting wet. I'm guessing that there is a lot of water stored up behind the leak that will want to keep oozing out.

 

[Eric L Schultz]

Thank you, it is a nice pond and makes a really nice roar when both pumps are running. It'll put me right to sleep.

I'm hoping that there's someone out there who has a seriously out-of-the-box idea for fixing this as there are a lot of really resourceful people out there and I'm certainly not the first person with a leak behind a huge wall of rocks.

 

[addy1]

That is beautiful!

Did you check the plumbing line? See if it is cracked, if you can see it.

 

[Eric L Schultz]

Hi Addy1

That's not a bad idea, however the plumbing for my pump is all inside the confines of the pond walls until it is above the waterline. Sorry I didn't say anything in my original post about how the plumbing was run.

Thank you, I do appreciate the suggestion.

E

 

[JamieB]

Eek. The only thing I could think of is the one thing you say you won’t do; remove rocks to find it. However, with no fish or plants, you do have some options. If you have a general idea of where it is at, you could try filling the gaps with a waterproof expanding foam, to try and hopefully block the waters rout to the hole. But to do it right would require moving rocks. We do wish you the best of luck!

 

[addy1]

Well with two liners, with more protection below the rocks, it almost sounds like something, IE a critter has chewed through the liner.
I doubt the rocks shifted enough to cause a hole, you would see shifting in the top rocks if that happened.

Are there rocks on that front edge also?

When it is dry, have your worked your way around the pond looking for moisture? In looking at your photo you might not be able to even see dirt.

Without removing all the rocks, your only solution might be a liner in the lower pond. But it would show and would not catch all of the water flowing down.

Second possible option. Coat the rocks below the water line with water proof concrete, working it into the rocks where the water is coming down to seal as best as possible for the water fall. You can add color to it to try and blend it in with the rocks. If you shoved it into all the cracks between the rocks, like a real good grout job, you could leave the face of the rocks without concrete.

 

[Tula]

Wow, what a gorgeous waterfall.....I'd sleep like a baby hearing that

 

[bagsmom]

This is incredible! I wonder if you could pay someone to help you? Even though I'm way down south, I purchased a lot of my equipment from Nathan Brunk of Practical Garden Ponds -- he is PA but I don't remember where, specifically. I wonder if you could contact him and perhaps he could recommend a reputable professional close to you? It probably wouldn't be cheap, but it might be worth it if someone could help you keep this beautiful water feature!

 

[Lisak1]

Like everyone else I have to say what a gorgeous water feature! I also have to say I agree with everyone else that this is a deconstruction fix - which I know is exactly what you didn't want to hear.

If you are confident the leak is in the pool and not behind the waterfall itself (which is sounds like you are) then perhaps you could try putting a liner over the rocks to create a pool within a pool. It would be tricky to camouflage, but not impossible I don't think. And a piece of liner is cheap compared to what it will cost to have the whole thing re-done.

The challenge would be two-fold: obviously hiding the liner so it doesn't detract from the beauty of the water feature, but number two would be installing it in such a way that it doesn't allow water to get behind the liner.

The other idea would be what @addy1 suggested and try to find some way to "grout" the rocks to keep water from getting behind them. The only problem with that idea is you'd have to make sure that the water isn't able to get behind the rocks from the top all the way down. Just because MOST of the water flows over the rocks doesn't mean ALL of the water flows over the rocks.

Here's my third idea - I don't know what you pay for water where you are, but how about just adding an autofill. Then the feature would stay full and you can forget it's a problem! (My husband would call this a typical wife fix!)

Have you tried the old milk or food dye in the water to try and see where the leak is occurring? Perhaps isolating it to one area would make the fix a bit more manageable.

I feel your pain - that's a heck of a lot of work to build and you certainly took all the precautions when building it. And I bet that would cost thousands had you had it built for you. Good luck with figuring this one out. We're here for you!