Rainwater Harvesting Australia

by Dec 11, 2020Environment, Statistics & Data

Rainwater Harvesting is the process of collecting rainwater from surfaces typically roofs in Australia into Rainwater Tanks, and subsequently storing the water for later use.

Rainwater Harvesting is now considered a major strategy for water conservation in Australia. In this article we will cover all the statistics and data involved in this process. 

Data Sources: National Geographic, Health.GovAustralian Government Bureau of MeteorologyStatista

Australia on the Brink of a Water Crisis

The Driest Continent on Earth

Australia is the driest populated continent on earth with an average annual rainfall of around 470mm per year (the global average is 990mm). Most of the rainfall is concentrated along the north and east coasts with around 600mm per year, half our country gets less than 300mm per year. Climate change predictions suggest our rainfall could drop by 50% in the coming decades.

  • Our population is expected to increase by 40% over the next 30 years
  • We consume an average of 340 litres of water per person per day (global average 214 litres)
  • We are the greatest per capita consumers of water on earth, despite being the driest!

The Drive to Reduce our Water Consumption

The majority of the water that Australian households consume can be reduced with better management and systems in place. As the data shows below:

  • 50% – Outdoor use (car washing, hosing driveways, garden use)
  • 17% – Showers
  • 13% – Toilets
  • 11.5% – Laundry
Interesting fact!

A dishwasher uses only 10% of the water compared to washing in the sink!

Rainwater Harvesting

largest sources of water in Australia
  1. Surface water (dams)
  2. Groundwater
  3. Rainwater Harvesting

Rainwater Harvesting currently provides an estimated 274 billion litres of water annually.

Rainwater Harvesting Australia - Rainiwater
Water usage from rainwater tanks

80% of households with rainwater tanks consider the volume of water supplied sufficient for their needs which includes:

  • Drinking water
  • Garden watering
  • Toilet flushing
  • Laundry usage
  • Replenishing domestic pools or spas
  • Car washing
  • Supplying the hot water system
  • Thermal buffers to insulate houses
  • Ventilation for buildings
  • Protecting homes from bushfires

Although Rainwater collected from a well-designed and operated system can be suitable for all domestic use.
A common strategy for rainwater harvesting is to use the collected water for the garden, and some indoor use (toilet flushing, showering) while sourcing drinking water from a mains water supply.

Domestic Rainwater Tanks in Australia


  • 15.8% – Households with rainwater tanks
  • 7.3% – Use rainwater as main source of drinking water
  • 6.6% – Urban areas (Including Byron Bay)

  • 22.1% – Households with rainwater tanks
  • 13.2% – Use rainwater as main source of drinking water
  • 15.2% – Urban areas (Brisbane, Gold Coast, Toowoomba, Sunshine Coast)
Reasons given for not installing a rainwater tank

  • 47.5% – Set up Cost
  • 28% – Lack of time
  • 15% – Lack of room
  • 1.4% – Health concerns
Rainwater Harvesting

Rainwater Catchment

The average area for rainwater catchment for Australian households:

  • 100-150 ㎡ – Small House
  • 150-200 ㎡ – Medium House
  • 200 ㎡ + Large House
Rainwater Harvesting - Roof Catchment
Estimated Volumes of Rainwater Harveting (Location Based) 

Average person consumes 124,100 litres of water per year in Australia.

Brisbane: Average Annual Rainfall – 1200mm

Roof Size Litres Per Year
125㎡ 150,000
175㎡ 210,000
200㎡ 240,000

For more information on Brisbane Climate visit: Water Tanks Brisbane

Sunshine Coast: Average Annual Rainfall – 1478mm

Roof Size Litres Per Year
125㎡ 184,750
175㎡ 258,650
200㎡ 295,600

For more information on Sunshine Coast Climate visit: Water Tanks Sunshine Coast

Byron Bay: Average Annual Rainfall – 1833mm

Roof Size Litres Per Year
125㎡ 229,125
175㎡ 320,775
200㎡ 366,600

For more information on Byron Bay Climate visit: Water Tanks Byron Bay

Toowoomba: Average Annual Rainfall – 724mm

Roof Size Litres Per Year
125㎡ 90,500
175㎡ 126,700
200㎡ 144,800

For more information on Toowoomba Climate visit: Water Tanks Toowoomba

Gold Coast: Average Annual Rainfall – 1555mm

Roof Size Litres Per Year
125㎡ 194,375
175㎡ 272,125
200㎡ 311,000

For more information on Gold Coast Climate visit: Water Tanks Gold Coast

To find out how much rainwater you can harvest from your roof checkout our Rainwater Harvesting Calculator

Average Water Bills in Australia (2020)

Household Size Average Per year
1 $884
2 $1,072
3 $1,248
4 $1,292
5 $1,488
Rainwater Harvesting - Australian Dollar
Rainwater Harvesting - Australian Dollar
Number of days an Australian can live without water

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