Rainwater tanks


Using rainwater is an easy and effective way to conserve Melbourne’s precious water supply and reduce the amount of mains water you use.

It can provide greater security in times of water shortages and is exempt from the Victorian Government’s Permanent Water Use Rules.

Using rainwater will also save you money as it will supplement some of your household’s water use over the long-term.

How to use rainwater

Before using rainwater, consider adopting other simple and effective ways to save water.

Rainwater can be used for many purposes around the home such as watering your garden or washing your clothes.

Using rainwater for drinking purposes is permitted but is undertaken at the choice and risk of the property owner. There is no guarantee that the water is free from contamination and its misuse could have serious health consequences.

Visit EPA Victoria for more information on using rainwater in and around your home.

Using rainwater safely

Rainwater can be contaminated by a range of sources including industrial pollutants, dust, leaves, pollen, pesticide sprays, fertilisers, debris, vermin, birds, small animals and insects.

Tanks should be installed in a way that minimises the risk of contamination, and regularly maintained to protect water quality.

Here are some steps you need to take to keep your rainwater supply safe:

  • keep your roof and gutters clear of large tree branches, leaves and debris
  • install screens between the roof and water tank to prevent access by animals and leaf litter
  • regularly check inlet and overflow screens to make sure they are clean, secure and in good condition
  • regularly check filters and other catchment areas
  • install a first flush or other diversion system to drain the first rainfall catch
  • install a water tap filtering device
  • check your tank for sludge accumulation every 2 to 3 years.

Visit Department of Health website for more information.

You can also call us on 1300 322 322 for advice on health issues related to rainwater use in your area.

Choosing a tank

Your local rainwater tank supplier can provide you with detailed information to ensure you obtain a tank best suited to your needs and property.

Things you should consider:

  • cost
  • size of required tank
  • amount of rain you expect to capture
  • how the rainwater will be used
  • how you will regularly maintain your tank
  • preferred material such as polyethylene, concrete, galvanised iron or fibreglass
  • site preparation for installation such as the connection of overflow to the existing operating stormwater drainage system.

To find out which size tank you will need, use the online Tankulator tool, developed by the Alternative Technology Association.

Permits and approvals

There may be permits or regulatory requirements you will need to meet when installing and maintaining a rainwater tank.

Plumbing work

Certain classes of plumbing work may only be done by a licensed plumber such as connecting your tank for indoor use.

A Plumber's Certificate of Compliance should be supplied for work (including materials and labour) to install a rainwater tank where the total value is $750 or more (including materials, labour and GST).


Most rainwater tanks do not require a planning permit. However, you may need a planning permit if:

  • the tank exceeds 4,500 litres
  • will be located in an area covered by a Heritage Overlay
  • may impact or require the removal of vegetation.

Domestic rainwater tanks do not require a building permit as they are not classified as a building. However, you may need a building permit if the tank is supported by an existing building or contained within, or on, a proposed building.

Building regulatory requirements

Rainwater storage tanks are permitted to project into the minimum setback from a side boundary, required by Building Regulation 414, by 500mm. This means that tanks up to 3.6m in height must be a minimum of 500mm from a side boundary. Tanks in excess of 3.6m in height will need to be setback at a distance greater than 500mm from a side boundary, depending on the site.

You may also need to request the location of a stormwater discharge point or get approval to build over an easement before commencing work.

For more information, get in touch or view the Rainwater Fact Sheet(PDF, 624KB) .