Kitchen Garden Forum

I love all things about nature, but it does throw a spanner in the works on an odd occasion.
Where i've been working today they have a lined garden pond thats about twenty feet by fifteen feet, it's been there for about ten years, but i noticed today that nearly a third of the pond liner has lifted in one huge bubble.
All i can think that has happened is the water table has built up so much pressure under the liner it has pushed it up.
Although we are high up on a hill on clayey soil there are quite a few springs around, so with all this heavy rain, it's all i can think of.

Has anyone else come across this before, i'm hoping when the water table goes back down the weight of the water in the pond will push it back down.

oh no!
if it needs re lining will that be your job?

I will end up doing something with it no dought.
But time will tell what it is.

oldherbaceous wrote:I will end up doing something with it no dought.
But time will tell what it is.

Accidently poking it with a fork, no doubt.

I was thinking about that Peter, but theres an awfull lot of pressure under there, i suppose i could charge them for installing a fountain.
When i first saw the swelling it looked like there was a whale in the pond.

Could it be attributed to a mole OH.....perhaps a very large mole?

Are you up to taking a photo of the problem OH?

Dear Weed, if it is a mole it must be massive, as the hump is about ten foot long and four foot wide.
Mr Potato, would you like an under water photograph or an above one.
I could do an above one but i still need to master the art of getting them onto the computer.
I'm hoping it will have gone down a bit by next thursday when i am there again, but i'm not very optamistic.

Hope you were not suggesting i'm not capable of using a camera.

Just thought you might be too distraught... Bulging bottoms can be alarming at the best of times...

I see OH what we have is a large mole with a bad attitude!

Seriously, even if the raised section does go down there is, I suspect, going to be significant damage to the pond's foundations....it will have to go

We have had some serious rain over the last few years I would hazard a guess that this damage could have been building up for some considerable time

I think if i start taking photo's of bulging bottoms, i could get myself into more trouble than usual, i will check some out tomorrow though, i happen to know there's a couple of big ones down the other end of the village.

Dear weed, it's a butyl liner in the pond so im hoping it will unstrech itself, but i think it will be an ongoing problem now the water has found a weak spot in the clay.

Maybe i could bottle the spring water and sell it.
Milton Bryan Spring Water, now there's a thought.

Hi OH,
Is it possible to dig a hole, as close to the pond as possible, that goes deeper than the bottom of the pond because that could well relieve the pressure and the liner may well sit itself down again.
Only a thought mind.
JB.

And a very good thought Johnboy, it wouldn't be the easiest of jobs, as the pond is over three feet deep, but i think that it might very well work.
It's one of them old sayings again, two heads are better than one.
Thankyou Johnboy.

Yep..I've encountered this before,in a pond about 30ft across and it turned out to be trapped air. It could be that the filling up of the water table has pushed the air out of the soil and it can't escape.We had quite a simple solution which involved loosening the liner in a couple of places around the edge then lobbing in a couple of large rocks,the air moved over and eventual exploded out the side in what can only be described as an enormous belch and the smell was absolutely foul,very methaney so something had been rotting away very nicely down there and contributing to the bubble.This did not puncture the liner and you do have to be careful there are no sharp bits on the rocks.
To stop it happening again we pushed a length of largish diameter hosepipe down the escape route which is hidden at the bank end by planting which vents the air.
Hope this helps.

Hello Carole B, first of all how nice it is to see you back, i have really missed your replies, especialy in the mornings.
Hope everything has been well with you.

Your answer is very interesting, and i will be able to find the answer to it next week.
Better not put any naked flames to close, just incase it is methane.

Maybe three heads are better than two.

Hope you don't disappear again.