Please see the description here (http://www.phillipjohnson.com.au/smallspaces/box-hill.aspx?) and then pic 7.
How does it sustain itself without the need for mains water? I'm not sure that there is enough rain in Box Hill through the summer months to stop it from drying up? Also, if you did something like this, would you need a pond pump etc?
I would love a frog pond here and am curious as to how this one in particular 'works'