Help - pond is leaking!

Our 4m x 2m (1.5m deep) wild-life pond has had a small leak for a few years now, so is always 10-12cm below full. We never managed to find where the leak was so learned to live with it, but recently the level has dropped to about 30cm from full -despite all the rain -I think this must be due to the local heron who has been visiting lately!  How do we find the leak ?  How do we repair the butyl liner? And how do we do all this without disturbing the wildlife (tadpoles, minnows, great diving beetles, dragonfly larvae, etc., etc.).  The pond was installed by a professional but he has since retired and his business no longer exists.


  • marshmellomarshmello Posts: 683

    To find a leak in a liner, let the water find its leaking level. Then examine the water line on the liner, if you still cannot locate the hole, drain a few more inches of water and it should be more obvious to the eye.

    They are plenty of products on the market for such repairs...

    Scroll down the page for the repair kits - I have never ordered from this site.

  • Gary HobsonGary Hobson Posts: 1,892

    The answer depends in part on the maturity of the pond.

    If it's a mature pond, the chances are that there will be established plants all around the perimeter (in the water). Plants such as water iris form dense mats. In such circumstances it is quite impossible to see the liner.

    If the pond is 1.5m in depth, and you've lost 30cm, then there is still well over a metre of water in the pond. I guess that the creatures are all perfectly happy with that.

    Encouraging wildlife into your garden is partly about having a relaxed attitude, and letting nature take its course. It's not about fretting and thinking that things must be 'put right'.

    If you can see the liner, and can fix the leak, then do so. But personally, I'd be inclined to live with it.

  • Chrissie3Chrissie3 Posts: 5


    Thanks for the link.  We have not had chance to look for the leak yet, due to an unexpected trip into hospital. (I'm fine now.) I also seriously underestimated the size of the pond - it's actually 15m x 4m - and as we have lots of plants around the edge we've decided to tackle it a section at a time.

  • RueberueRueberue Posts: 8

    My rather large puppy, has systematically chewed through several areas in my pond, so that I have some large holes, and (of course not much water).  I had a problem with duck weed.  So have let the pond dry out and will now clean it out.  Has anyone had any experience of mending large holes, especially on the edges of little terraces.  Any advice - welcome.  I am hoping that my bees will then use the pond for their water, and so deter the puppy - now fully grown.

  • darren636darren636 Posts: 666
    Gold label pond repair is great for patching up liners.

    Finding the leak is the problem.

    Clean it up really well before allying patch and glue
  • RueberueRueberue Posts: 8

    Clean with soap and water and dry or/and give it a bit of a light sanding?

  • DicemancDicemanc Posts: 40

    If you still can't detect the leak after letting the water find its level and cleaning the liner, then here is a tip I came across on the internet...

    Fill above the leak level again and drop a small amount of milk into the centre of the pond. The milk should drift towards the leak so you can see the position around the edge where the leak is (the rate of drift will depend on how fast the leak is...)

    NB - I haven't done this myself, so I can't vouch for how well it works - but it sounds like a reasonable solution, even if it is off a random website!

    Good luck.


  • RueberueRueberue Posts: 8

    That is a great tip.  There are some huge holes in the pond, but more then likely some small, difficult to detect ones as well.



  • Sarah38Sarah38 Posts: 4

     Hi - my wildlife pond on my allotment started losing water this spring. Have left it till now to investigate so that this year's amphibians could grow and escape. When I lifted the liner this week, all along the first shelf was a series of small very round holes - like the liner had been pierced with a series of varying sized hot needles. I will have to dismantle the pond completely and replace the liner. Anyone got any ideas about what could do this sort of damage? Help please!

  • FairygirlFairygirl Posts: 19,692

    Hi Sarah, sounds like animal damage of some kind doesn't it? When you say it's on the shelf, do you mean on the base of it? That would suggest little sharp claws of some kind as something enters/leaves the pond. Do you have a sloping 'beach' for animal access? That might help guide any creatures away from the shelves in future.

    Replacing is a pain but there's probably no other solution unless you can just repair that section with the product recommendation in an earlier post, and then use something more robust on the shelf to protect it. Not sure what exactly, but some heavy duty rubber or even just a good layer of sand if that's feasible. Keeping it contained would be the issue there.

    Not sure that's much help to you really, but prevention of future damage is possibly the only solution.

  • Sarah38Sarah38 Posts: 4

    Thanks Fairygirl - am off to replace the liner now. The holes don't look like claw damage - they have no 'tear-back' edges and are completely round. I'm stumped. Yes, I do have a beach area but your idea of making that shelf more protected is good - I will do that as I have some left over liner and bits and pieces I can put under the liner in case the attack's source is from the soil.  What sort of creature can penetrate a liner with a 40 year guarantee is a bit scary but I think that's all I can do. Many thanks for your reply.

  • FairygirlFairygirl Posts: 19,692

    I think you definitely need something on top of the liner as well Sarah. Belt and braces image

    Is it possible a person has caused the damage with something? It came into my head because yesterday I was removing the bamboo skewers I had in bare areas to deter the endless local feline population from s****ing everywhere. They would make a very small puncture hole. 

  • Sarah38Sarah38 Posts: 4

    Did occur to me Fairygirl, but the holes are all of differing sizes and all over the place so I put the thought away (leaving aside the idea that someone hates me....) Yesterday I emptied the old liner, took everything out, put all the frogs and wildlife into a temporary pond and laid the new liner. Worked for 7 hours and it looks great..again. However, when I lifted the temporary pond which I had made from a liner I had about 20 years ago I noticed it had exactly the same holes. I also now know that the holes were made inside the pond as they are on the inside of the liner folds, not penetrating through the 3 thicknesses. Am feeling very pessimistic about the future of my new pond. There's obviously something with very strong jaws hanging around my allotment.

  • FairygirlFairygirl Posts: 19,692

    Can you rig up a camera at all Sarah -just to see if you can get an idea of the culprit? I don't know what else to suggest. It would be a pain if you have the same problem after all your work.

    Layering up the shelves and any other edges where there's direct access is the only solution I can think of image

  • Sarah38Sarah38 Posts: 4

    Thanks for all  your suggestions Fairygirl. A camera would be difficult but will try adding lots of pebbles along the shelves and see what happens. Next try will be a preformed pond, as I'm determined to beat this!

  • FairygirlFairygirl Posts: 19,692

    I hope you can resolve it Sarah. It's such a valuable resource and wonderful to watch everything using it. I just realised it's an allotment pond rather than a garden one so it would be more tricky to find out what's causing it. Perhaps the preformed one is the way to go after all. Good luck image

Sign In or Register to comment.