Ideas for pond surface/lining

[tanny]

Ok in the field (middle of nowhere actually) we have prepared the hole for a large pond for water retention and fish, but the price of rubber liners has gone crazy here meaning a cheap liner will be circa 2-3,000 euros. Does anyone have any ideas of a different product or surfacing that can be used please.
TIA
We are in Cyprus, so hot in summer and location can be cold in winter..

 

[Lisak1]

What's your goal? Your use of the term "water retention" is slightly confusing. Here we build retention ponds to hold excess water - they can dry down to nothing during times when we have no rainfall. But if this is for a fish pond you need a reliable way to hold water, obviously.

Have you looked into bentonite clay for lining a pond? There used to be a member here who started a bentonite liner but he left the forum before it was complete. But if you search for bentonite you'll likely find some info.