Water under liner

[cetimmons]

I just built my pond last year and just had our first heavy rain storm last week. after the storm I found my liner had bubbled underneath and most of the water was out of my pond. I have saved the fish and drained the pond and reconstructing it. I just wanted to know if anyone has some advice about the pond edges to prevent this from happening again? Thanks!!!

 

[DrCase]

Welcome to the Forum
Raise the edge of your pond higher
You need more water weight in your pond than around it

 

[taherrmann4]

I had this happen for the first 5 or so years during especially heavy rains maybe once a season on average. During the five years I made several adjustments to try and keep this from happening besides tearing out the whole pond and relocating it. For one my pond sits in a spot in my yard where it is surrounded by a hill on one side, water used to drained from the land next to me right through my pond now goes around via a drainage pipe, and then half my gutters on the back side of the house drain in that direction. Like Dr. case stated build it up higher if you can, I could not do that without ordering all new liner and completely redoing it. So I have made some tweaks on it and so far they have worked.

I started out by putting in a rock island which my buddah also sits on in the middle of the pond.

My water lillies weigh a lot so they help hold it down as well.

I have a cypress tree in a 10g pot that sits in the bottom of the pond.

I have several decent size rocks strategically located throughout the bottom of the pond. My pond bottom is 80% uncovered so only 20% covered by rocks and tree if I had to guess.

Then two years ago I put in a drain pipe on the low end of my pond where the overflow spot is. I dug down about 12" and put this 2" pipe in next to the liner then it exits out about 10' away from the pond. What I have noticed by doing this is water still gets under the pond but now works its way up to this pipe and exits where as before it had no place to go. How I figured to do this was every time I did get water under the liner I would take my pond vac or extra pump I had and stick it about 6" below the water level of the pond on the outside of the liner and there would be all this water, so as the pump started sucking the water would remain there lowering it under the liner in the other parts of the pond thereby allowing the liner to fall back down to the bottom of the pond. By doing this it would suck about 90% of the water out from under the pond. So I figured I would give this simple method a try and it worked for me.

My soil is clay and I could have built a natural pond without a liner probably. The next time I have to redo the liner in another 15 yrs or so I will make it deeper and a bit higher as it currently sits below the surround landscape. Newbie mistake but you live and learn.

Good luck.

 

[HARO]

If nothing else works, dig out a hole beside the pond, place a large pail with holes drilled in it in the hole, and fill around it with coarse gravel. A cheap sump pump sits in the bucket and drains the excess water from around the pond. Just make sure the water is pumped far enough away that it doesn't flow back into the hole.
John

 

[adavisus]

If you are familiar with using a siphon, a pipe can be left in place to a low point of the pond liner for drainage purposes and set it up to drain water until its gone when it is needed

Regards, andy

 

[j.w]

cetimmons

 

[Mmathis]

We just dug our hole this w/end, and already having some seepage around the 2' level. We also have clay soil and fair-to-poor yard drainage. Don't have a liner in yet (right now, covered with a tented tarp to keep rain out).

I was wondering about elevating the side edges by making a wide berm with some of the soil we dug up. How high & how wide can we reasonably make the berm?

 

[addy1]

My dirt berm is 5 foot tall, base is around 5-6 foot (I think) top is around 1-2 feet. It is the downhill side of our pond.

 

[Mmathis]

Do you have to reinforce it?

 

[addy1]

Do you have to reinforce it?

no just dirt, larger base, smaller at the top

 

[PondTBD]

I'm almost done digging & someone suggested installing Agi pipe (slotted drain pipe used for french drain) in the bottom before installing liner. Agi pipe comes out from under liner on side to route water out above pond water level. Pressure of water in pond pushes any water/gases under liner through the Agi pipe to the surface. Anybody every try this? -thx

 

[DrCase]

I would just put the liner in and be done .
forget about trying to make water go up hill .

 

[B-Herbal]

Welcome to the Forum
Raise the edge of your pond higher
You need more water weight in your pond than around it

I find your input very helpful. I just put in a decorative pond 20x20x3.5 and it's liner, heat shaping/seaming the ldpm to fit correctly. No leaks. I placed it in a high area -still got water under it on the first heavy rain. The liner came up on the bottom where I didn't have stones placed. So, if I extend the top edge out a foot from the stone edge (will heat seam more material around the edges to do this), bury that new flap convex in the soil over a small burm, put riprap and smaller pea gravel to cover the bottom and each shelf, will this help? Outside of putting in a sump pump to collect water and disperse it? After looking at all the responses I see I'm not alone in putting in a pond liner (clay base/geomat under it) then getting air/water under the liner - even weighted down with belgain block regulars. They are about 15lbs each. lol So the pond edges need to be higher, I get that. But does it matter about the liner edge direction - does it have to be horizontal or must it be vertical pointing downward into it's anchor trench? I assume letting it stand vertical up behind rocks is a bad no-no as rain will just go right in behind it, as well as water run-off.

To the person who said they don't think they need a liner with a clay base - > I tried that first and here I am putting in a liner. Cattails take over, the clay sides collapse because clay can hold an enormous amount of water (it's clay of course and can hold up to 300% water), the shelves collapse into one big u-shaped pond. Luckily I'd started small and had room to build back in the shelves. If you care about shelves and clear water in a decorative pond, put in a liner of sorts. I chose LPDM as I can heat shape it and seam it with a heat gun/plastic weld gun to make it conform to the pond's shape, simulating a formed pond liner. Just be careful not to leave holes. One can attach all sorts of things to an lpdm liner, like cord anchors/guides, shower stall decorations that are on mesh - like the stone walls decals - to act as pebble anchors and cover the liners.

Anyway, any input on this rain water issue with a well-placed location is appreciated. Until further notice, I'm extending the burm and liner edges to see if that helps. Good luck everyone.

 

[j.w]

and welcome @B-Herbal

 

[GBBUDD]

@B-Herbal this is an old thread i don't think i have seen drcase once in the 6 years i have been coming here. Placing rock on the liner may solve the problem water is looking for the path of least resistance.

Digging along the side where it is the wetess and placing an empty pipe VERTICLY size varying on how much water there really is.

If your on clay but it wouldn't hold water well mixing in bentonite can be the answer .