mystery holes in the liner

[Becky]

@Becky Could you move this one to a different topic, as well — maybe “equipment”? Might help the OP get more views.

Done

 

[guitarman023]

Do you have kids?

 

[Mmathis]

Do you have kids?

Good point!

 

[Dorset Pond Man]

Thanks for your suggestions
I do have daughters, aged in their late 30s , on this occasion I feel they are innocent!
The heron is a possibility - but he's a damn poor shot!
The liner is thick Butyl laid over pond matting (I am not sure what the correct name is but it is designed to provide extra padding to resist punctures).
Still a mystery

 

[sissy]

Moles did chew my liner in several spots and the holes were small also .I am guessing when water came out they would stop chewing and go to another spot .The moles were after grubs so when I replaced the liner I put lots of milky spore on the dirt and the used roofing paper I had left from the house build as a preliner and then used the stuff that you are supposed to put under the liner next .Milky spore kills the grubs that the moles chew on .I suspect it may have been mice also since i live in the country where field mice are bad .I also have seen large damp bugs that chew liners at a neighbors house .The bugs were huge and dark brownish red .

 

[NotMike]

I have exactly the same type of holes in my butyl liner. About 15 years old. It’s not a puncture, it looks like a wear hold, that is formed by continually being abraded at the same spot. Looking at my photos I can see many areas where abrasion has stated and part of the liner has been worn through.

However there is one difference between mine and the OP. His were above the water line, mine are below.

i have asked chat GPT and it gave a lot of “well thought out” suggestions. I didn’t show it my photographs. But there was nothing that I thought could explain them.

 

[NotMike]

Moles did chew my liner in several spots and the holes were small also .I am guessing when water came out they would stop chewing and go to another spot .The moles were after grubs so when I replaced the liner I put lots of milky spore on the dirt and the used roofing paper I had left from the house build as a preliner and then used the stuff that you are supposed to put under the liner next .Milky spore kills the grubs that the moles chew on .I suspect it may have been mice also since i live in the country where field mice are bad .I also have seen large damp bugs that chew liners at a neighbors house .The bugs were huge and dark brownish red .

Moles would attack from behind the liner. Could the bugs be dragon fly nymphs?

 

[GBBUDD]

welcome @NotMike this post is from 2018 you can add to the topic but the authors are from 2018 . the date of the post is stamped top left of the text

 

[PhilipCSwift]

My 16 year old Butyl liner has developed small roundholes and is leaking as a result, any idea what might have caused them?

I have these too in an old butyl liner. They are perfectly round holes, so it has to be critter of some sort. Try using large flanged black pop rivets to seal them off. 20 5mm x 8mm aluminium and steel rivets cost £3.23. Tape and fillers don't last.

 

[j.w]

@PhilipCSwift

 

[GBBUDD]

Those look like beetle tunnels. a piece of epdm is no match to them compared to tunneling through wood. and their tunnels like what your showing are perfectly round. an other possibility are worms and grubs. One thing i did do when i was building my pond was i noticed tons of grubs and i mixed in poisons in the back fill.

 

[PhilipCSwift]

@Dorset Pond Man Have you had rocks piled on top of or under the liner? And was an underlayment used when the liner was installed? If not something chewing it, it almost looks like worn spots.

What about birds (herons or something pecking?) or even critters digging from underneath the pond and liner. @sissy I believe had critters damage her liner from underneath.

And another thought, do you know the warranty info on the liner? If the liner is 16 years old, maybe it’s at the end of its useful life-span. Did you install the liner yourself, or was it already in place when you acquired the property? Maybe it’s older than you think. Just a wild thought....

2025: I have these. It is probably dragon fly nymphs. The holes are indeed perfectly round, similar to holes in UK crab apples.
You can repair the hole with a round stick. Just poke it in! This will last a few months. Permanent repair can be done with Waterproof Patch & Seal Tape Black, washered rivets or butyl rubber plugs and UV setting glue.

 

[Lisak1]

A good argument for making sure liner is all concealed? I’m assuming this is happening where liner is exposed -

 

[j.w]

See now I am not sure a dragonfly nymph can chew through a rubber liner. I need more proof. I looked online and cannot find anything saying their jaws are that strong. Not saying the person is wrong just want some scientific proof.

 

[GBBUDD]

See now I am not sure a dragonfly nymph can chew through a rubber liner. I need more proof. I looked online and cannot find anything saying their jaws are that strong. Not saying the person is wrong just want some scientific proof.

My vote would be outside in . like a grub or any other bug that lives in the soil and tunnels