What Regulation Applies To Private-use Water Tanks?

When you install a water tank, especially the cheapest rainwater tanks, you need to make sure that it gets installed under the state government requirements and specifications. There are regulations in Victoria that must be followed when installing a private-use water tank.

Requirements for rainwater tanks

To install a rainwater tank in Melbourne you need to adhere to regulations by the Plumbing Code of Australia, which is a standard that is found in the National Construction Code. The code that endorses the Plumbing and drainage standards AS/NZS 3500.

There is a 6-star standard that is in the National Construction Code that requires rainwater systems to have the following:

  • A minimum rainfall catchment area of 50m2 
  • Rainwater storage that is connected to all flushing toilets within the home in order to use rainfall for sanitary flushing
  • Rainwater storage needs to have a capacity of at least 2,000 litres

According to the Building Authority, the variations of the energy provisions of the Building Code requires a new Class 1 buildings to have either:

  • A solar water heater system
  • Install a rainwater tank that is connected to all flushing systems

The class 1 buildings that are single dwelling homes or attached dwellings that are separated via a fire-resistant wall, a hostel with a floor area that does not exceed 300m2 and where no more than 12 people are living.
Also including an extension or any additions to the Class 1 buildings that have roof areas that are larger than 50m2 and has a water heater, cold laundry outlet or water closer.

Connection Requirements for Rainwater

The main installation requirements for all water tanks are easy to comply with and reasonable. Within Victoria, there are two different types of conditions- backflow prevention related and connection related. 

Here is the summary for both:

The connection requirements

  • A continuous supply of water that is provided by automatic or manual devices for switching between the mains water and rainwater.
  • The installation of your tank system must be compliant with the AS/NZS 3500, along with the requirements for the backflow containment of your local water authority.
  • All the connection systems and piping, appliances and outlets. Fixtures must get installed via a registered plumber.
  • All the piping that carries the water needs to be marked with “Rainwater” in a bright colour and along the lines at intervals within 1 metre apart. The water outlets need to be labelled “rainwater”, and the taps must get identified with markers that are “RW” initials, green in colour.

What is required for backflow prevention?

If the water tank is being used for non-drinking purposes within the building, there needs to be an interconnection with the main water. There are several requirements for this interconnection:

  • A device for automatic or manual switching between the mains water and rainwater is needed
  • A method is known as a dual check valve to help protect the rainwater from entering the mains water supply
  • A hazard testing device to prevent water contamination is a must if the tank is either partly or entirely installed into the ground.
  • You need to have a registry and commissioning by your local water authority of all the containment prevent devices is needed before use. The device must be tested annually by a qualified plumber.

Compliance Certificate

Compliance certificates are documents that are required by the Building Authority after there has been any plumbing work completed that came to a cost of more than $750.
This type of certificate can only be given by a registered plumber who must supply you with this certificate within five days of completing the work. The details on the compliance certificates are required to be lodged with the Building Authority in the same timeframe. 

Local council tank requirements

  • Space will need to be allocated within the tank for fire fighting
  • The water overflow must be directed to the stormwater drain
  • You must have a tank installed by a plumber that provides you with a certificate
  • The container needs to be screened or hidden so you cannot see it from the street
  • The positioning of the tank needs to be at least 500mm away from the boundary of any neighbouring properties.