Getting the best value out of your rainwater tank
You’ll need to consider:
1. How much rainwater you can capture, which depends on:
- the yearly rainfall in your area
- the amount of roof area connected to tank (the area connected to downpipes draining to tank, refer to image below)
- the size of your tank
2. The ways that rainwater is used by your household:
- indoor (toilet, laundry, hot water service, kitchen) and
- outdoor (garden, “leaky tank”)
Rainwater tank size selection chart
Using the information above, these simple charts (links below) help you to select the best rainwater tank size for your requirements.
If you’re not able to increase the size of your tank, try:
- diverting other downpipes to the tank to increase the area of rainwater catchment
- installing other rainwater collecting devices such as rain barrels, mini rainwater tanks, drums – get creative!
- connecting more wet areas in your home (e.g. washing machine, toilet) and garden irrigation to the tank
- increasing your overall water efficiency
Rainwater harvesting specifications – for the home
Rainwater harvesting residential design specification developed by Rainwater Harvesting Association of Australia and Urban WaterCycle Solutions.
Rainwater harvesting calculator
Tankulator is an online rainwater harvesting calculator that can help you plan for a new rainwater tank or improve the performance of an existing tank, developed by The Alternative Technology Association
To help you decide what size rainwater tank you need, you will need to know your roof or catchment area. Visit the Google Map Developers’ website to calculate your roof area by satellite view.