Water loss from wildlife pond

[Gulvain]

Hi guys,


I need a spot of advice about my wildlife pond. I dug the pond a few days ago and lined it with Epalyn and a layer of geotextile above and below the liner. It looked fantastic immediately after I filled it but since then the water levels have dropped by at least 5-10cm and left a muddy mess

The liner is new so I am pretty sure it is not a leak. Evaporation seems unlikely as the levels have dropped so dramatically. The only thing I can think of is the surrounding soil and perhaps also the geotextile fabric have wicked away the water. The surrounding soil is sandy and very porous and is damp so this seems to be the most plausible.

Has anyone encountered this problem before or have ideas ideas about how to stop it. I really don't want to have to keep continually topping up the pond!

Thanks

[treecreeper]

I've not done this, but one of my books recommends this method. Fill a squeezy bottle with bright red food dye and squirt blobs of it every few inches round the edge. If the problem is associated with a particular area you will see the blobs moving towards it.

[Elean0r]

The same sort of thing happened when we put in our pond, although it wasn't quite as bad. Despite our best efforts to make sure the liner was level all the way round we found it wasn't, and we could only properly level it when it was full of water.

We also realised that water will "wick out" along creases, so turned the edge up and inwards, towards the water, rather than out and downwards into the surrounding soil.

[Gulvain]

Hi guys,

An update on the situation..

Over the weekend I cut off the overlaying geotextile fabric and replaced half of the soil around the lower side of the pond with a gravel perimeter to try and reduce the amount of water loss through wicking.

So far there has been no noticable water loss from the pond. I think it's one of those issues that no one tells you about before putting a widlife pond in but something that you may have to deal with after.

For anyone with planning to put in a pond in sandy/light soil my advice would be to think about ways of reducing the area of contact soil adjoining the pond and certainly cut off any geotextile fabric overlaying the liner (which can really wick up water) to a level below the planned water level.

[acherontia]

I hope you have many years enjoyment happy in the knowledge that all your efforts will be rewarded and appreciated by the wonderful wildlife you'll get.

The more the merrier for pond digging, says I!
I'll wager it was difficult keeping that sandy soil from falling back in?
I dug out from clay last year and although it was very heavy going at least the holes stayed there!! I could've made enough bricks for a small shed with all the pure clay I took out. No wonder this area has so many old brick crofts that are now wonderful water reserves.

Acher

[Elean0r]

Originally Posted by Gulvain

Over the weekend I cut off the overlaying geotextile fabric ...

Out of interest, why did you put the geotextile on top of the liner rather than beneath it?

[Gulvain]

Hi,

I put geotextile both below and above the liner. With hindsight I wouldn't have bothered with anything above because of the wicking problem. However, I thought an overlayer would give a bit more protection to the liner from above and I found that it held the backfilled soil in place well.