Jon Rouse wrote:

Hello Jon

It was the only option before concrete and liners, and
since then isn't much used.
JR Except in every canal in the country.

Very good point.

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.
JR Not true. Canals are usually built higher than the
JR surrounding land to prevent flooding.

But supplied with flowing water, and a certain amount of leakage is a
given and factored into the design when built, and the scale of
building is somewhat more than a garden pond. There's also a
considerable amount of effort gone into keeping the level exactly so.

But not many canals being built these days, so difficult to say
whether a modern material would be used in preference.

JOOI, do you know if anyone's done any costings on whether imported
clay works out cheaper than, for example, butyl (4ukp per square
metre)?

Lot of work too, which is why most are done with liners
these days.
JR You do it in your bare feet, and get all the local kids
JR involved. Don't put the red carpet out though!



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