In article , Simon Avery
writes


It /can/ work well, apparently, but only if the ground is naturally
wet all the time anyway - ie, a low lying boggy area with a stream.
And if the water level drops then the clay dries out where it's
exposed and cracks.

Lot of work too, which is why most are done with liners these days.

A friend has a very, very large pond in her garden, ( about 80' x 60')
built in the wettest part with trees all round so shaded, they hired a
digger and flattened the surface with the bucket part thumped up and
down, all over before allowing it to fill naturally. Seems to have
worked for the last eight years
--
Janet Tweedy
Dalmatian Telegraph
http://www.lancedal.demon.co.uk