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No.1 Rainwater Tanks & Water Pumps Online Store in SA

Call us on 0466 987 999

Choosing a Rainwater Tank


STEP 1: Determine the size in litres of the tank that you need.

Work out your roof catchment area that will be used to fill the rain water tank. Once you figure out the roof area, use this simple calculation you can determine how much water you will collect per average annual rainfall. For every 1mm of rain falling on a 1m2area of roof will be approximately 0.9 Litres.

Use this link to learn more about the average rainfall in Australia

0.9 x Average Rain Fall In mm x Square Meters Of Roof

(e.g. 0.9 x 1200mm x 150 = 162000 Litres per year)

Next work out what you will use the water tank water for e.g. flushing toilets, washing machine, and garden taps etc. You then can use the following table to calculate your daily rainwater demand.

One flush of a dual flush toilet


One load in a standard washing machine


Washing of an average size car


Hosing of a driveway


Standard garden sprinkler


Drip style sprinkler



STEP 2:  Determine where you want to locate the tank.

Find the most appropriate area in your yard for the water tank. Take into account that you need to run a downpipe to fill the tank, it’s not going to impeded access down the side of the house and local council guidelines. Now measure the designated area that you want to situate your rainwater tank.


STEP 3:  Calculate which water tank is best for you.

Using all your previous measurements and calculations you can now decide on a tank from our extensive range which is best suited to your needs.

E.g. You have a space down the side of your house that is 1200mm wide and 5000mm long with a space 3000mm to your eaves. You could fit a 5000Litre slimline  water tank that is 825mm wide x 4075mm long x 2180 high. This would give you approximately one and a half weeks of rainwater to use if the rainwater tank was full.


STEP 4:  Choose a colour of your tank.

All water tanks are available in 15 COLORBOND tank colours.


When selecting your tank colour, it is important to know where you will place your tank and to choose a colour that match your houses paint scheme. E.g. You can choose the water tank colour to match your fence or roof. 


Colours are shown for illustration purposes only and may vary.


STEP 5:  Choose a pump that best suits your needs.

If you are using the tank water for toilet flushing etc, a Davey Rain Bank Switch is recommended. This will automatically switch over to mains water supply for flushing of the toilets and washing machine when the tank level drops too low. If the tank water is only going to be used to water the garden and wash cars etc a standard pump can be used.

STEP 6:  Choose your tank accessories.

Decide if there are any extra accessories that are needed such as a water level gauge, water pump connection kit, Pump Cover, first flush diverter, rainwater  filters etc.