25 July 2024

Are rainwater tanks compulsory across Australia?

Whilst rainwater tanks are undoubtedly beneficial, they are not compulsory in new builds across Australia. There have been various periods where certain states made it compulsory for new builds to include water tanks as part of the build, and in some states, there are still regulations that enforce the installation of water tanks in new builds, either commercial or domestic.

The requirements for new builds to include a water tank varies from state to state and can also be dependent on the size of your property and the location within a particular state. You can read more about each individual state requirement below.

Although rainwater tanks are not compulsory across all states in Australia, they are actively encouraged when people are commissioning new build projects or making significant changes to an existing property.

Rainwater tanks bring a huge number of benefits, both to homeowners and businesses, not to mention the environmental benefits they bring.

With Australia’s climate seemingly becoming increasingly unstable, with more and more significant weather events, including both drought and flood conditions, water tanks are becoming an essential part of many homes as the government, both at national and state level, look to combat the increasing demand on potable water supplies, whilst also reducing the impact of stormwater runoff on the ever-fragile eco-system of Australia.

Benefits of water tanks

Before we look at the individual state legislations relating to the installation of water tanks, let’s first take a closer look at some of the benefits of water tanks, with a particular focus on Australia.

Water tanks have become an increasingly essential tool in tackling water management across Australia. Whilst water tanks used to be common across the country before a time when municipal water was readily available, they have been making a resurgence over the past decade as homeowners and businesses looking to take their water management into their own hands.

Rainwater tanks provide a great way of capturing the rainwater that falls naturally onto your property. This is typically collected from the roof, with downpipes filtering the water from the gutters into your water tank, with various filters incorporated to stop debris from entering your tank.

Water tanks come in various shapes and sizes and once you have collected and filtered the water from your roof, it can be used for a number of tasks around the house, from flushing the toilet to washing the car to watering the garden.

Some water tanks can be hooked up to the house for potable use (drinking, cooking bathing etc), however, there are strict guidelines around this and filtration systems you need to put in place to ensure the water is safe to consume.

For those looking to use the water they collect from non-potable uses, it is much easier to set up your water tank system. However, you will need a plumber to install a system that allows you to flush your toilets and do your laundry, especially to ensure no backwash enters the municipal supply.

We’ve already talked about some of the broader benefits of installing a water tank on your property, however, let’s take a closer look at some of the benefits for you, as well as the environment:

·        Provides you with a sustainable source of water, even when water restrictions are in place.

·        Saves money on your water bill by using rainwater collected from your roof to water the garden, wash the car, flush the toilet, or in some cases, shower, drink and cook with.

·        Reduces the strain on the stormwater runoff system.

·        Reduces the strain on the municipal water supply, making more water available to those who cannot install a water tank.

·        Some people prefer to use natural water rather than water that has been treated in mains supplied water. Water varies by state, and some find water to be soft, hard, or have a metallic taste. Rainwater harvested from your roof provides an attractive alternative.

Are water tanks compulsory in New South Wales (NSW)?

The NSW Government has implemented residential building requirements that aim to deliver sustainable water and energy, known as BASIX. BASIX assessment is required for:

·        New buildings that consist of one or more dwellings

·        Conversions of an existing building to a building that consists of one or more dwellings

·        Additions and/or alterations to buildings that consist of one or more dwellings with an estimated work cost of $50,000 or more

·        Swimming pools with a capacity of 40,000L or more

BASIX aims to achieve a 40% reduction in the consumption of potable water against the state benchmark. Rainwater harvesting systems are a great way to achieve BASIX certification for your proposed development. Rainwater collection is assessed based upon:

·        The capacity of the rainwater tank being installed

·        Roof catchment area that will be connected to the rainwater tank

·        How the tank water is used

·        Running overflow from your rainwater tank to another tank for collection and re-use

In NSW you must also comply with the development regulations articulated in the State Environmental Planning Policy. Many specific requirements are provided depending upon whether your rainwater tank is installed above or below ground. Some of these include:

·        Plumbing your tank into your house and/or interconnecting to mains water needs to be carried out by a licensed plumber

·        Your water tank cannot be placed on the footing of an existing building

·        Screening against mosquitoes and other insects breeding inside is ensured

·        The overflow of the tank is connected to an existing stormwater drainage system

·        The water tank is placed in the rear yard, behind the building line

·        Protection against vermin entering the water tank is ensured

·        Protection against ingress of stormwater and groundwater if the tank is partially or completely buried in the ground is ensured

If you are planning a new build project in NSW, it pays to check the BASIX website for more information before you decide whether a water tank is right for you or whether you have a legal requirement to install one.

Are water tanks compulsory in Victoria (VIC)?

Looking back 10 years, Victoria fell some way behind NSW when it came to rainwater collection. With no standards or regulations in place and BASIX already in place, the majority of new builds in Victoria did not require a water tank as part of the build project.

Jump forward 10 years and Victoria is slowly catching up. Whilst the rules and regulations are still complicated, and vary at all three levels of government – local council, State of Victoria, and national guidelines – many new build projects are required to install a water tank as part of the build.

Australia’s National Construction Code provides the minimum necessary requirements for safety, health, amenity and sustainability in the design and construction of new buildings (and new building work in existing buildings) throughout Australia.

The Victorian Building Authority requires all new homes, home renovations, alterations and additions need to comply with the Six-Star Standard in the National Construction Code. In relation to rainwater tanks this means:

·        Having a minimum rain catchment area of 50m2,

·        Having a minimum capacity of 2000 litres, and

·        Plumbing into your rainwater to be used for toilets

It should be noted that complying with the Six-Star Standard is a requirement for new homes and building projects that require a building permit. If you are considering a new build project, it is always recommended to check in with your builder who should be aware of the National Construction Code and be able to advise whether your new build requires a water tank installation.

Are water tanks compulsory in Queensland (QLD)?

Queensland is a state that has been hit by extreme weather conditions, including both drought and flooding. Whilst the state is fairly progressive when it comes to the installation of rainwater tanks, they are not compulsory on new builds state-wide.

Instead, water tanks can be either:

·        Voluntarily installed

·        Required with a new house or commercial building where a local government has been approved to 'opt-in' to the relevant Queensland Development Code (QDC)

According to the Queensland Government Business website, “Where a property is located in a local government that has been approved to opt-in to the QDC, a rainwater tank or other supplementary water supply system must be installed with that new building.

“In all other areas of Queensland, it is voluntary to install a rainwater tank or other water supply system (e.g. a greywater treatment plant).”

A rainwater tank may also be subject to local government planning scheme requirements for siting and boundary setbacks to correctly locate it on the property.

If you use a rainwater tank, there are minimum capacity and connection standards for the tank's installation:

·        For a detached house, the tank must have a minimum capacity of 5,000 litres.

·        For a non-detached house (such as terrace houses, townhouses and semi-detached houses), the tank must have a minimum capacity of 3,000 litres.

·        All rainwater tanks must receive rainfall from at least half of the available roof catchment area or 100m2, whichever is lesser.

·        The tank must be connected to:

o   All toilet cisterns and washing machine cold water taps (for internal use)

o   At least one tap, typically a garden tap (for external use)

·        An automatic switching device or a trickle top-up system may be needed to ensure a continuous water supply for internal fixtures supplied from a rainwater tank.

New residential buildings required to install a supplementary water supply system must also meet the minimum health and safety standards in QDC 4.2, including:

·        Measures to prevent insects and vermin from entering or breeding in a tank

·        Measures to prevent contaminants from entering the tank

·        Requirements for signage on tanks

·        Appropriate design and construction of stands and supports, openings and overflows

Like other states including NSW and Victoria, it is always best to check with your local council when it comes to the specific regulations in the area you are planning a new build and if you are thinking of installing a water tank at an existing property.

Are water tanks compulsory in South Australia (SA)?

South Australia recently made rainwater tanks compulsory in new builds that meet specific requirements, a progressive step by the state to actively manage both water consumption and the impact of stormwater runoff.

According to the South Australian Government website, “South Australian building rules require that new dwellings and some extensions or alterations, have an additional water supply to supplement mains water.

“The most common way to meet the additional water supply requirement is to install plumbed minimum-sized rainwater tanks – other options include:

·        A recycled water scheme

·        Connection to a community rainwater storage tank.

“The additional water supply must be installed before a house or extension is occupied.”

New houses built in South Australia are now required to install a rainwater tank of at least 1000 litres. The tank must be plumbed into the toilet, to a water heater or to all cold water outlets in the laundry, and the inlet and overflow must be fitted with mosquito-proof screens.

The same rules apply to new extensions or alterations with an area greater than 50m2 that include a toilet, water heater or laundry cold water outlet.

Are water tanks compulsory in Western Australia (WA)?

At the time of writing, rainwater tanks are not compulsory in Western Australia. They are, however, encouraged by the state as a way of conserving water. Like most Australian states, there is an imbalance when it comes to rainfall and usage. In the winter months when rainfall is high, demand tends to be much lower, whereas, in the hot summer month when demand is high, rainfall is at its lowest.

There are currently no real incentives for people to install a water tank in homes throughout Western Australia, however, this could change as demand increases and all Australian states are put under greater pressure at national level to manage the water supply and ecological impact of installing water tanks, especially in new build projects.

Are water tanks compulsory in Northern Territories (NT)?

Like Western Australia, at the time of writing, there are no enforced regulations in the Northern Territories relating to the installation of water tanks in new builds.

There are some guidelines when it comes to the voluntary installation of water tanks and these should be consulted before you carry out any work to install a water tank in the home or commercial building.


Water tanks are not compulsory throughout every state in Australia and even at state level, they are not always compulsory across every state region.

It is always best to consult your builder or even your local council if you are starting a new build project and want to find out more about installing a water tank in the home.

At Smart Water, we have a range of solutions when it comes to managing your water and monitoring your usage, helping you to keep on top of your consumption and ensure you manage your water usage efficiently.

Easy to install yourself, your Smart Water tank indicator provides you with all the information you need from our app or from one of our LCD displays. Find out how much water you consume on average from your tank, accurate pressure data and estimates on when your tank will run out of water based on current usage.

Find out more about our range of products or check out our FAQs for more information.