Do some internet searching for something to put in the pond to slow the
leaks down. Maybe there is a clay or something that will suspend itself in
the water and clog the cracks up as it runs out the hole,
"Nicholas Walker" wrote in message
...
I've recently scooped out an old silted up pond in my garden which filled
up
and overflowed every winter but dried out in the summer. It's a fairly
large triangle of about 20 yards each side. It takes four days to fill
with
a hose and then two days to drain. The clay base (of unknown thickness)
seems watertight, but I reckon it's leeching out where the clay meets the
topsoil sides.

What are my options? It's a bit big for a liner but I understand that the
clay could be extended up the sides. What is the technique for doing
this?
How thick does the layer of clay need to be? How do I test that the clay
to
be used is up to the job?

Many thanks in anticipation