kitey writes
Hello,

I have just moved into a new house that has a badly water logged
garden, due to it being a clay soil.

I have just replaced the boiler which has left me with 2 1m3 cold
water tanks.

My question is, if I bury these tanks upside down in the garden,with
6-12" of soil on top, what area of grden would each tank drain.

Not much more than 1 sq m unless you have a system of drains channelling
the water into the tanks.

6-12 inches of soil is not a great deal, especially if we get a hot
summer. You would have problems with dry soil on that area.

--
Kay