harvesting rainwater factsheet

In Australia, fresh water is a valuable and limited resource and rainwater can provide a renewable supply of natural water that we can use for a range of purposes including drinking, washing, bathing, laundry and in our garden.

There are four main steps to consider when considering harvesting rainwater

1. How much water you use and therefore what sized tank you require
2. Where to locate the tank
3. Finding a rainwater tank supplier and plumber
4. Maintaining your tank

1. How much water do you use?

To work out what size of tank is suitable, it is advisable to first identify what you want to use your rainwater for. For example:

  • For small quantities in the garden, a 600 to 1500 litre tank might be sufficient
  • For use in your toilet (flushing), 2000 litres or more can make a difference
  • For laundry washing, hand washing and in the shower, a 4000-5000 litre tank is recommended.

If you can afford a larger system and have the space, plumbing your tank into the mains is a great idea!

With 80% of Perth’s rainfall arriving in 5 winter months, it is difficult to use rainwater all year round, unless you have a very large tank. However, a moderate sized tank will greatly assist in eliminating most mains water use during winter.

2. Where to locate your tank

Look for a gutter collecting rain from a significant proportion of your roof area. Remember, the roof and gutters also need to be in good condition. You will then need to look for a physical space alongside the house up the 2.3 metres high and 1-2 metres wide depending on the size and shape of tank you choose.

You will also need to check with your local Council to see what approvals are needed. Such approvals can depend on factors like the tank’s proximity to the boundary fence or its height or size.

3. Find a rainwater tank supplier and plumber

If your rainwater tank is to be plumbed into the mains, a licensed plumber is required to connect your tank. You can find suppliers of tanks in the Yellow Pages under “tanks”.

4. Maintaining your tank

It is important you regularly clean your gutters and filters and de-sludge your tank every 2-3 years. For more information on maintaining your tank speak to your supplier or visit www.public.health.wa.gov.au/3/659/2/rainwater_collection.pm