Rainwater tanks
A rainwater tank collects and stores rainwater, typically runoff from the roof piped through the gutters. Rainwater tanks have many advantages – no matter where you live. In many parts of regional and rural Australia, and on some urban fringes, rainwater tanks are essential to collect water for household use. However, even in urban areas rainwater tanks can help save drinking water and reduce runoff.
Why use a rainwater tank?
Rainwater tanks have a number of benefits, including:
able to be used indoors and outdoors, such as for flushing toilets, washing clothes and in the pool
a variety of shapes and sizes to suit all homes
reducing the impact of stormwater on drainage infrastructure, roads, urban streams and beaches
reducing contaminants in our waterways
reducing your water consumption
reducing the amount of sewage discharged to the ocean or rivers
reducing your water bills
Is it safe to use rainwater?
Although rainwater tank water may be used for drinking water, the NSW Department of Health does not recommend drinking rainwater from your tank, where a mains water supply is available. More information is available in NSW Health's rainwater tank brochure.
Do I need a plumber to install a rainwater tank?
Rainwater tank connections to the toilet or washing machine must be performed or supervised by a NSW licensed plumber and meet requirements under the NSW Code of Practice for Plumbers and Drainage. This requires an individual to hold either a contractor licence or qualified supervisor certificate in the class of plumbing. Plumbing work must be certified by the licensed plumber who performed/ supervised the work and cannot be signed off using a company contractor licence.
Many local water utilities also require an inspection of rainwater tank plumbing. Your plumber is required to notify the local water utility on completion of rainwater tank plumbing work and will be able to advise you about local water utility requirements in your area.
For information on selecting a licensed plumber, refer to the NSW Fair Trading website.
How much does a rainwater tank cost?
Generally the cost of a rainwater tank will depend on the size and type of material it is made from: metal, concrete, polythene or fibreglass.
Other costs may include delivery and installation, hiring a NSW licensed plumber to connect the water indoors (if required), a pump (if not gravity supply) and ongoing maintenance costs. We recommend contacting several suppliers for quotes to ensure you get good value.
What size rainwater tank do I need?
The appropriate rainwater tank size will vary depending on the size of your roof and yard, the number of people living in your house, and the rainfall in your area.
Please note that in most council areas, rainwater tanks larger than 10,000 litres require a Development Application to be lodged. You need to check council requirements before you buy your tank.
What is meant by mains water, town water, reticulated and drinking water?
Mains water is water of drinking quality, typically supplied in Australia by water authorities, local government or utility companies, through a network of pipes to premises in urban areas. Different authorities have different terms for mains water and may refer to this as drinking water, town water or reticulated water. Water of drinking quality may also be referred to as potable water. Households in rural areas that provide their own water, for example from rainwater tanks or dams on their property or by piping it from local waterways, are not on mains water.
Is it safe to drink from a rainwater tank?
Although rainwater tank water may be used for drinking water, the NSW Department of Health does not recommend drinking rainwater from your tank, where a reticulated water supply is available. More information is available in NSW Health's rainwater tank brochure .
What is backflow prevention?
Rainwater tanks connected to toilets or washing machines must have a backflow prevention device to stop water from the tank mixing with the mains water supply. This ensures the quality of mains water is not affected by your tank water. The licensed plumber who installs your rainwater tank will need to ensure appropriate backflow prevention is in place.
What does mains top-up mean?
In order to ensure water quality, rainwater tanks should not be allowed to run dry. Most rainwater tanks, especially ones that are plumbed into the house, are topped up with mains (drinking) water. This ensures that there is always water available to flush toilets and wash clothes during long periods without rain.
Because the rainwater tank will be supplemented with mains water when levels get low, you may still be subject to water restrictions if they apply in your area. Contact your local water utility to check the water restrictions in your area and restriction requirements for rainwater tanks with mains top-up.
What is a first-flush device?
A first-flush device ensures that the initial rainwater collected from your roof does not enter your rainwater tank, but washes into the normal stormwater system. This helps to reduce the amount of contaminants and sediment from the roof entering your rainwater tank. First-flush devices are available from rainwater tank suppliers.
Can I use my rainwater tank to water my garden if it's plumbed into the house?
If your rainwater tank is topped-up by mains water, you may still be subject to any water restrictions in place in your area. Contact your local water utility to check what water restrictions apply and restriction requirements for rainwater tanks with mains top-up.
What are the council requirements for installing rainwater tanks?
Council requirements vary across the state. You will need to contact your local council before installing your rainwater tank to ensure it meets requirements. Councils may need to inspect your tank.
What is involved in maintaining my rainwater tank?
There are several things which need to be done to maintain a rainwater tank:
Install first-flush devices, screens and guards to prevent debris and insects entering the rainwater tank. First-flush devices are essential for reducing the amount of sediment and other materials entering the rainwater tank and polluting the water.
Inspect gutters and roof catchment areas regularly and keep them clean and clear of leaves and debris. Regularly clean screens and guards. Keeping your rainwater flowing cleanly and quickly into your tank reduces the build up of sludge as well as the risk of mosquitoes breeding in your rainwater tank.
Check for sludge in your rainwater tank at least every 2-3 years. If sludge is covering the bottom of your rainwater tank, you'll need to remove it by siphoning it out or completely emptying your tank (contact a professional tank cleaner for advice). A lot of sludge means you may need to pay more attention to your roof and gutter areas. Remember to make sure you prevent mosquito access to your rainwater tank. If you find mosquitoes in your rainwater tank, find the entry point and seal it.
More information is available from the NSW Health's rainwater tank brochure.
Where can I get a rainwater tank?
Look in the Yellow Pages under 'tanks' and 'tank equipment' to find a supplier who can help you. In order to assess the best option for you, we recommend contacting several suppliers for quotes.
Page last updated: 07 January 2013
