Design principles

Central systems and common areas

Central systems can reduce potable water use by:

  • monitoring and managing cooling tower make-up water; 
  • controlling water bleed in cooling towers; 
  • storing fire sprinkler test water for reuse during the next test; 
  • providing central rainwater or stormwater harvesting; 
  • and providing on-site water recycling.

Potable water use in common areas can be reduced by:

  • reducing the water used for landscaping and gardens; 
  • choosing water-efficient fixtures; 
  • and choosing water-efficient appliances.

Pool and spa

To reduce the potable water use for a pool or spa limit the evaporation from them. You can do this by:

  • installing a cover for your pool or spa
  • providing shading to the pool or spa

Tip: potable water use can also be reduced by using rainwater to top-up pools and spas

Alternative water

By using a non potable water supply as an 'alternative water source', where appropriate, it is possible to significantly reduce the amount of potable water used by your development.

Different types of alternative water require varying levels of treatment and the uses permitted for an alternative water source will vary depending on the type and the treatment method selected.

Alternative water sources recognised in BASIX include; rainwater, stormwater, grey water, recycled effluent, and for single dwelling developments only, private dams.

Acceptable uses can include:

  • garden and lawn
  • toilets– only if all toilets are connected
  • laundry
  • hot water– only if all hot water uses the alternative water source
  • household uses– only if all water uses the alternative water source
  • pool and spa top-up
  • cooling tower make-up water


Use water-efficient fixtures to reduce the amount of water required. If the fixtures are for hot water then you will also reduce energy required for water heating.

The water efficiency of fixtures is rated in accordance with the Water Efficiency Labelling and Standards (WELS) scheme. Choose products that are more water-efficient by choosing products with more stars.

The scheme covers:

  • showerheads
  • taps and tap outlets
  • toilet suites or matched cistern and pan sets
  • appliances such as dishwashers and clothes washing machines.


Landscaping will affect the water consumption of a proposed development. Generally, the greater the garden and lawn area in a proposed development, the more water that is required to maintain the garden in a healthy state. In drier and hotter regions in particular large areas of garden and lawn can have a significant impact on a development's overall water consumption.

Reduce potable water use by:

  • planting areas of low-water-use and indigenous plant species, rather than typical lawn or plant species not suited to that location
  • providing alternative water sources for irrigation

photo of low-water-use indigenous plantsResidential garden featuring low-water-use indigenous plants