Rainwater: collecting, consuming and conserving

Rainwater, even when collected in the heart of a city like Sydney, is completely safe to drink. Through years of testing rainwater at his own house, Michael Mobbs has even shown that it’s cleaner than mains water.  Rainwater will be collected and used to meet all my potable water needs; by reusing treated greywater for my non-potable water needs, installing low-flow taps and shower head and purchasing water efficient appliances, I will maximise the amazing and free resource that is rainwater.  Initial tests of my rainwater show it’s cleaner than mains water.


All the rainwater that falls on my roof will be collected and stored in my backyard, none of it will be wasted. Although it is not uncommon to have a backyard rainwater tank storing roof-harvested rainwater, I went an extra step and decided to also capture the water off the front portion of my roof that would otherwise fall onto the street and become polluted stormwater.

The water that falls on my roof (both on the front and back sections) will go into self-cleaning gutters that leave leaves and debris behind. The water will then flow into a device called a “first flush” that directs the first layer of dirty rainwater straight into the garden. The remaining, clean rainwater is diverted into a series of above ground and underground rainwater tanks.


Once the rainwater is in the tank, it’s ready to be used! It is pumped into the house on demand by a Davey pump when a tap is turned on (the Davey pump only uses 200W to get the water into my house). It will have a bladder, like a tyre bladder, which will prevent the pump coming on each time the tap is turned on; the air in thebladder propels the waterto the tap and when the air runs out thepump cuts in. Simple as that. Any overflow from the tank system goes into the backyard absorption pit, and it is all kept on-site.

I love my rainwater system because I know where the water comes from, where it’s been, and the energy required to get it to my taps and shower head (gravity and a simple pump). If you’re using city mains, here’s a small glimpse into the long and inefficient journey your water has taken:

To get water from dams to houses, water flows through 21,000 kilometres of pipes. Placed end to end, these pipes would stretch from Sydney to Los Angeles and back! There are also 164 pumping stations, 251 reservoir tanks and nine water filtration plants that are all part of Sydney’s drinking water system

That’s a lot of energy and resources that could all be avoided!  Remember: you can’t turn on your tap without burning coal or gas,  unless you use a raintank and solar energy.


Even if you’re not ready to make the switch to rainwater, here are five simple and FREE things you can do to save the amount of water you use.

1.     Use the dishwasher instead of washing by hand; energy and water efficient dishwashers use less water than washing dishes by hand. If you do have to wash dishes by hand, don’t let the water run. Fill one basin with wash water and the other with rinse water.

2.     Use one glass for your drinking water each day or refill a water bottle; this small change will cut down on the number of glasses you have to wash each day. If everyone in your house does this, that’s several glasses each day that you don’t have to wash.

3.     When doing laundry, match the water level to the size of the load and use cold water; this saves water and energy, and helps your clothes retain their colour.

4.     Toilet leaks can be silent and waste lots of water! Be sure to test your toilet for leaks at least once a year by putting food colouring in the tank, if it seeps into the bowl without flushing, there’s a leak. On that note, replace any leaking faucets as soon as possible because all those drops add up to a lot of water at the end of the day! In the meantime, but a pitcher underneath the faucet to collect that dripping water and use it later.

5.     If you’re due to replace your taps and shower heads, make sure you buy efficient models that range from 4 to 7 litres per minute depending on the application. Old taps and shower heads can use as much as 20 litres of water per minute! This small fix will result in huge water savings.