You do not need a big tank to start catching rain. Our first system was a 120-litre dustbin under the downpipe by the back door.
How much you can catch
A roof catches about one litre per square metre for every millimetre of rain. A 20 mm storm on a small roof can fill several bins.
Keep it safe
- Fit a tight lid or mesh to keep out mosquitoes and children.
- Use it on beds, not for drinking.
- Empty and clean it once a year.
We have since added two proper tanks, but that first bin taught us how much water was running down the drain.