On 31 Mar, 09:55, "PK" wrote:
"sm_jamieson" wrote in message

...

To make it look good you need real rocks (from a local quarry or
landscape gardening place. Build a big waterproof tray



Build a set of recessed steps into the bank, line with butyl, sit big rocks
on the steps, arrange small rocks and scree to hide the liner.

some numbers on water flow hehttp://www.californiawaterscapes.com...fall-build.htm

pk

We used a cheap liner (PVC) and regretted it ever since. Butyl
stretches so it is less likely to rupture when pulled tight over a
stone.
Simon.