Last Friday the first trial drain garden was installed in the footpath outside 13 Oxford St, Newtown as part of Kylie Ahern's off-grid renovation.
The drain garden has these components: a sump into which water drains from the road gutter; two long pits with plants and grates over through which the plants may grow; an overflow point for when the pit fills; capacity to harvest over 29,000 litres of road water a year.
It's designed to bring previously wasted road runoff to irrigate the tree roots below the surface. The aim is to increase the tree height and canopy and to thereby cool the street. If we harvest previously wasted road stormwater to irrigate trees we can cool our cities by several degrees and increase the health of the air we need to live and that's needed by all that's living in cities.
We'll monitor and report on its performance, particularly the accumulation of sediment in the first sump; there's a removable 'pot' to enable easy removal of sediment.
The cost to Kylie of this trial drain garden is $2400. With simpler design and multiple production we expect this to halve.
We're seeking rate rebates and exemption from stormwater levies for Kylie from the local council and the local monopoly water provider, Sydney Water. We're asking governments to give rate rebates to farmers and householders who conserve water and energy on their land and provide a public benefit beyond their boundary. We'll keep you informed about this, too.
Unfortunately, in the brutal way only governments can be, the local council imposed a $3,000 developer levy on Kylie's renovation approval for it to carry out stormwater works; an act of silliness but that, too, is a work in progress as Kylie is seeking a refund.
Anyway, hang on sad tree, water is on its way to you.