Evening all. The pond has a leak. Hours of back breaking work digging a way too big pond. Then lovingly building a stone waterfall, filling with plants and even managed to get newts setting up home. The kids love it.

And now it’s leaking. Gutted. My suspicion is the dog possibly having taken a dip and puncturing with his claws.

But I cannot for the life of me find the leak. It takes a few days for the level to drop. And seems to stop at the 6 inch mark but I can find no evidence of the hole. Any ideas?

Google suggested spraying milk and using ping pong balls. Done both. None the wiser…

Def a leak and not evaporation now the weather is hotter?

I had this, and I think it was because I’d folded the felt underlay back over and down the sides. I thought it would help protect the liner but I reckon it was wicking the water away. Not sure where I’d got the idea from to do that so probably not helpful to you. One idea might be to drop some small amounts of dye or food colouring in around few locations after filling it to see if that helps identify any holes?

How long have you had it and how many plants are in the pond, thought we had a leak but plants just take loads of water and noticeable when weather is dry, but could still be a small leak as mentioned at a fold or where it levels at 6″. In the end we took most plants out as massive root issue and now pond going great and full of tadpoles! good luck ponds are great.

def not evaporation sadly. although maybe the plants are sucking it up. It feels like a lot of sucking though. It’s a fairly large pond (3.5m x 2.5m) so to have lost 6 inches in a week seems like it must be a leak…

We had this a while back, there’s just no way of working out where it was leaking, so it was a case of draining and then resealing the whole base, absolute pain to do, only good thing was we weren’t on a water meter at the time!

Is the liner directly onto soil, and how porous is the soil? I’ve seen industrial containments with a double liner, and a semi porous fill between them, with sumps for monitoring. Could you dig holes round the outside and see which get water in them?

Wild idea – with the level just below where the leak might be, pour water with dye in it behind the liner, and see where it leaks into the pond? Keep the level on the outside just a few cm above the pond to avoid pushing the liner off.

Drain another few inches and then paint rubber sealant over the top 7-8 inches to cover any holes and then refill once dry?

Bucket test might help tell you if you have a leak. Albeit if the plants are drinking a lot then it won’t necessarily tell you much.

Bucket test is fill bucket with bit of water, float in pond and and mark water level on inside and outside, leave it and then see if water has dropped the same in the bucket and the pond. If pond drop is greater then indicates potential leak, but plants complicate!

Temporary plastic sheet covering one half of the perimeter and partway down the sides. If no leak, the hole is in that side so remove half the sheet and repeat until the leaking area is identified.

Foxes drink from my pond and often push the lining down at the sides while they drink. It can lose quite a lot if water.

Foxes drink from my pond and often push the lining down at the sides while they drink.

It could be squirrels. I have a squirrel trap you can borrow?

if its a hole, surely it will drain down to the hole and stop. Leave it to settle, then search along the water line? (or just tape along the water line with butyl tape)

Drain the pond, put in a new liner, fill again. I’m gearing myself up to do this, stupidly mismeasured when I renovated a few years ago, had to glue an extra piece on to one side, and it leaks slowly but steadily enough to cause trouble over summer. I’m pretty sure it’s the join, there may even be a root pushing through the gap.

Having 2 ponds makes it easier to keep the wildlife happy while the work’s in progress!

Foxes drink from my pond and often push the lining down at the sides while they drink.

It could be squirrels. I have a squirrel trap you can borrow?

I see the foxes do it all the time. Maybe squirrels too but not seen them do it.

Drain the pond, put in a new liner, fill again.

Only easy if its a small pond. Mines 4 x 6 meters so wouldn’t want to do that on mine.

They have to be very thirsty squirrels. I’m assuming this is a joke!

I think it’s relinimg time. Tbh I didn’t get it quite level first time round so it’s an opp to sort that out too.

if its a hole, surely it will drain down to the hole and stop. Leave it to settle, then search along the water line? (or just tape along the water line with butyl tape)

I’d mark the water level and fill up again and see if it stops at same line.

I didn’t get it quite level first time round

Well that’s your problem right there…all the water is running downhill 😁

They have to be very thirsty squirrels.

Or a very large group of slightly thirsty squirrels

Stans

Pump/waterfall UV filter leak ?

Or a very large group of slightly thirsty squirrels

Or a small group of very large, fairly thirsty squirrels.

We had a hole in the pond liner, like others have said, it was found by allowing the pond to drain until it stopped. It was then fixed with a puncture repair kit.

I was going to suggest what WCA said.
If the level stabilises at a certain point the that is presumably where the leak is ie. It will drain down to he hole but not below.
Take some more water out and seal around the ‘high water mark’

I’d try the bucket method listed above. I have a smallish container pond on the patio with various water plants and I am always amazed at how much the water level drops. I absolutely know it isn’t leaking as it is on the patio and I’d see the water but it still needs topping up surprisingly often.

The daft dogs drinking from it when there is a perfectly good clean water bowl a few inches away doesn’t help either!

You could scatter the grass clippings from the lawnmower over the pond.

As the water subsides, the clippings will accumulate at the source of the leak?