Alternate Water Supplies

Work In Progress

Whilst the system is presently using fresh mains water, I am considering using rainwater and/or grey water. This provides some complications however. Edit: I will be staying away from Grey Water as it is not good for irrigation. Advice is that Grey Water when used for irrigation should be used at least 10cm below the surface, never used with a sprinkler and never stored.

One Way Valve

A ‘Dual Check Valve’ or one way valve MUST be installed on the incoming water supply. These are available from Bunnings but are more expensive than you would expect. They should be installed on the incoming mains water supply regardless.

Food Quality Plastic Drums

A great way to store water is in food quality plastic barrels. They are commonly available in 200l drums quite cheaply, and can be joined together. They do need to be plumbed together if you want to use more than one, but this should be relatively easy.


Dual Pump – Rain Water

What I am considering for rainwater is a dual pump scenario. In essence, a sump pump would pump rainwater into the drums, and then a second pump would pressurise the water for use in the garden.

To do this, I would install a ‘storm water sump’ at the bottom of the garden where water would sit before being pumped into the holding tanks. If the sump fills up, the water would just continue on to the normal storm water drain.


eBay has 12V sump pumps for about $50. It is important it has an automatic cut off once there is no longer any water. Also, it is important it can lift the water high enough (head). Commonly these pumps will pump 5000 litres per hour. This is more than enough for our purposes. Search for something like “12v sump pump auto”.


It is important that the pump also stops once the tanks are full. Once again, eBay sells float switches.

Once more, rainwater pumps are fairly cheap on eBay. Installing a level switch for low water level would probably be a good idea. This pump would be turned on by Open Sprinkler.