"Malcolm Stewart" wrote in
message ...
"Doctor Drivel" wrote in message
reenews.net...

So you've essentially got a huge sealed plastic bag under the
patio/decking.
A 3m*3m*0.5m tank = 4500l.

Ideally you'd probably like to size this so that it fills completely
with whatever spare water you've got in the wetter months, for use in
the drier.

Just put a large tank down there, they come in sections, and cover with
decking.

Thanks for all the ideas. If only I could get a digger into my rear
garden!

What about the front?