"PaulK" wrote:

Hello PaulK

P The cracking problem is really only a problem when clay is
P imported to form a liner over permeable soils. I suspect
P that on solid clay the drying out and leaking problem would
P be less significant.

You're probably right, but even natural clay what has lived there for
millenia does dry out quite easily if allowed to. My old garden was
built on one of the largest ball-clay sites in Devon (Liverton
Coldeast estate for the locals) and with the obligatory new estate's
1" of grubby topsoil we had slimy soil in the winter and dust in the
summer. Just being clay doesn't automatically mean permanent wetness.

And now I've got a garden built over an old lead mine.

P Have a look in the books by Anthony archer wills, THE name
P in large scale water features.

Thanks, will keep an eye open.

Doing quite nicely with mine now, top pond (4' square, block) now
faced with granite, slate waterfall and 2nd small pond below all done.
To do: Line and fill big pond (5M x 15M), fit bubble fountain at top
point (12' lift), a 1/4 scale granite leat into top pond. Then a
series of ponds or slow stream from there to the big pond again.

The liner was supposed to be delivered today, but no way a lorry's
going to get up our road - needed my snowchains on to get the car up
just now.

--
Simon Avery, Dartmoor, UK Ý http://www.digdilem.org/