Rainwater Tanks

 

Please be advised that Regulation 83A of the Development Regulations 2008 has been amended to clarify the intent of the Regulation. From 29 November 2007 the amended Regulations makes it clear that all new Class 1a buildings are required to have all connections made for the supply of water from all sources prior to the occupation of the dwelling. That is, all sources of water identified in the development approval (mains, rainwater tank, third pipe scheme) must be connected before the dwelling is occupied. 

Since 1 July 2006 in South Australia building rules have required new dwellings (and some extensions or alterations) to have an additional water supply to supplement the mains water.

The additional water supply has to be plumbed to a toilet, to a water heater or to all cold water outlets in the laundry of a new home. The same rules will apply to new extensions or alterations where the area of the extension or alteration is greater than 50m2 and includes a toilet, water heater or laundry cold water outlet. 

These provisions will assist in reducing demand on the State's mains water supply.

Installing specially plumbed, minimum-sized rainwater tanks will be by far the most common way of meeting the additional water supply requirement.

Other means of providing the required additional water supply could include developments using a dual reticulated (fixed pipe) water supply system – such as Mawson Lakes – or approved bore water.

Plumbed rainwater tanks

If rainwater tanks are to be used to provide the additional water supply, new homes will need to be designed to ensure that rainwater from not less than 50m2 of the roof is:

  • Collected by gutters and downpipes;
  • Stored in a rainwater tank; and
  • Plumbed to a toilet or a water heater or all laundry cold water outlets.

If the roof catchment area of the building is less than 50m2 all the water run-off from the roof must be collected, stored and plumbed.

What size rainwater tank should be installed?

The rainwater tank must have a storage capacity not less than 1 kilolitre (1000 litres). The requirement for a minimum one kilolitre plumbed rainwater tank is additional to any other water storage tank requirements that might be required (eg other tanks are required in some areas for bushfire fighting purposes).

Where a number of dwellings contribute to a communal rainwater storage tank, each dwelling must contribute rainwater from 50m2 of its roof catchment area to the rainwater tank and water from the tank must be plumbed back to each individual dwelling. In these situations, the minimum rainwater tank size required is determined by multiplying the number of dwellings that contribute to the rainwater tank by one kilolitre for each dwelling. 

Are there any other requirements for the rainwater tank?

  • An overflow device must be fitted; and
  • A mosquito proof, non-degradable screen must be attached to protect the water quality.

Are there exemptions?

The following areas are exempt:

  • The Municipal Council of Roxby Downs
  • The District Council of Coober Pedy, and
  • Areas designated as Out of Council areas.

Plumbing requirements

The plumbing aspects of the policy are regulated by the South Australian Water Corporation (SA Water) in accordance with the Waterworks Act 1932 and Waterworks Regulations 1996. SA Water require all plumbing work to comply with AS/NZS 3500:2003, the National Plumbing and Drainage Code and any SA Variations published by SA Water. The technical requirements for rainwater tanks are contained in Section 14 of AS/NZS 3500:2003 Part 1 and the SA Water Variations.

A licensed plumber must:

  • install the piping system delivering the rainwater to the water closet, water heater or cold water laundry outlets and
  • complete a Certificate of Compliance certifying that the installation has been installed in accordance with AS/NZS 3500 and the SA Variations. The Certificate of Compliance must be provided to SA Water and the home owner within 7 days of completion of the work.

Development applications 

From 1 July 2006, all applications lodged for building rules consent for new houses and relevant extensions/alterations for houses, will need to include details of how they will meet the water saving requirements. If they are using rainwater tanks, this will include the size, location, area of catchment and plumbing details for the installation of the tanks.

For more information

Details of the new requirements are included in the South Australian Appendix to the Building Code of Australia (BCA) and the South Australian Housing Code (SAHC).

Government rebate - plumbed tanks for existing homes

The South Australian Government has a rebate scheme in place for homeowners who wish to purchase a package including a rainwater tank and the plumbing of a new or existing rainwater tank into an existing home.

Rebates of up to $1000 are available under the scheme administered by SA Water. 

For all details and eligibility criteria see the SA Water 'Rainwater Tank Rebate Scheme' website, http://www.sawater.com.au/SAWater/YourHome/SaveWaterInYourHome/rebates_rainwatertanks.htm or telephone 1300 650 950.