Leaking pond

[The Flying Tench]

We created our pond 3 years ago. Dug a 3 ft hole in the ground, put some carpet round the edge where we could to stop it getting punctured, and then put a liner in. It's been OK until a few days ago when the level dropped about a foot. Presumably a leak? Are there any hints on finding the leak and mending it? Do we need to get a pump and empty the pond?

[Elton]

Mine does that randomly, and I've never worked out why

[ahammond]

Repairing it is no problem. You can buy a kit a bit like a bicycle puncture repair outfit from most aquatics suppliers. There is one for UPVC liners and another which I suspect actualy is a bicyle puncture repair kit for butyl rubber liners. Finding where the leak is is the problem. To be honest though I would initialy suspect pipework feeding filters or ornaments. Check that first as it is normaly the easiest to do and leaks are pretty obvious. If that does not work watch the water level to see how far it drops then check the liner above it. There is no need to drain the pond and once the patch is on the job is done. I put one on my pond about four years ago and that is still holding good.

[ColinW]

Make a temporary pond out of polythene sheet supported by bricks, blocks, hay bales or whatever else you have handy so that if you have to empty the pond you have somewhere to put the fish. Then let the pond leak. When the level stops dropping you know you are close to the level of the hole. As you say you carpeted the bottom before installation, then you can get in the pond (it's the easiest way) and look closely around the water level (and a couple of inches down) until you find the hole. Usually, because the liner stretches a bit when you install it, the hole opens up and isn't too hard to find. When you find the hole, bale out a few more inches with a bucket, dry the area round the hole and patch it. If you kept any of the offcuts when you installed the liner then use them to make patches, I made patches about 4 inches across glued with Bostick 1 and have had no failures. I bought my liner dirt cheap because a careless shop assistant had cut some holes in it, so some of the patches have been there for twenty years now, way past the supposed lifetime of a plain PVC liner!

The worst case scenario is a hole in the bottom. In that case you'll have to completely empty the pond because the hole will be hidden under stinking silt.

The main problem I've had (as I say it is extremely old) are holes caused by sun damage, above the water line. Since you say your level dropped by a foot then that can't be your problem. To prevent that happening in the future make sure the "sun facing" side is well protected by overhanging stones or plants and always keep the pond well filled.

Edited October 20, 2006 by ColinW

[Elton]

The day after this thread was first posted, my pond dropped over a foot. It did it again the day before yesterday. It was fine in between.

 

I'm wondering, and this may sound daft, but I have a few big trees at the bottom of the garden. If one had managed to pierce the liner with a root, would I expect to suffer constant gradual water loss, or the 'once every couple of weeks' drastic loss that I'm getting now?

[ahammond]

I do not think that it would be tree roots as they would puncture the liner and allow the water to escape at a steady rate depending on the size of the hole made.

 

I have noticed that a combination of wind and sun will cause a far greater rate of evaporation than the sun on its own. But whether that would account for your water loss is doubtful.

 

I am afraid that I get the horrible feeling that you are going to have to drain your pond and thoroughly inspect everything to find the answer.

[ColinW]

If you have a pumped filter or fountain then I'd look for a plumbing problem. Maybe there's a fountain that misses the pond if the wind is in the wrong direction? If you haven't got a pump then I just don't know what to suggest.

[peter mccue]

I think ahammond is pretty close to the mark.

 

I have a scare late spring & early Autumn, I lose water so rapidly I'm damn well convinced I've got a leak! however, each time it happens it only lasts for a short time before the level stabilises & everything is back to normal.

 

What I've noticed is it tends to happen when the plant cover on the pond is low due to it either just starting to grow or it's dying back. When this is coupled with a strong drying wind & sunny days the water loss can be alarming. During the winter there is no problem, neither is there a problem during Summer.

 

As ahammond says, I feel there is a connection between the wind, temperature & sun which creates this rapid but temporary water loss. I think this atmospheric condition is more likely around May time & then again around October.

 

This is not to say you haven't got a leak in your pond, but it may well be advisable to hang fire a little & see what happens, you may find this to be a very short term problem.

[Jeffwil]

I think ahammond is pretty close to the mark.

 

I have a scare late spring & early Autumn, I lose water so rapidly I'm damn well convinced I've got a leak! however, each time it happens it only lasts for a short time before the level stabilises & everything is back to normal.

 

What I've noticed is it tends to happen when the plant cover on the pond is low due to it either just starting to grow or it's dying back. When this is coupled with a strong drying wind & sunny days the water loss can be alarming. During the winter there is no problem, neither is there a problem during Summer.

 

As ahammond says, I feel there is a connection between the wind, temperature & sun which creates this rapid but temporary water loss. I think this atmospheric condition is more likely around May time & then again around October.

 

This is not to say you haven't got a leak in your pond, but it may well be advisable to hang fire a little & see what happens, you may find this to be a very short term problem.

 

 

Culprit could also be herons stabbing through liner - it happens !