Historical rainfall data is easily available
In determining your tank size, first check the history of average annual rainfall in the area for the last 100 years or the longest period available. This information is usually available from the Bureau Of Meteorology. It is important to also determine on average, the longest periods without rainfall. Some areas get a great deal of their yearly rainfall at a particular time of year. To satisfy such a situation, a larger storage capacity would be required.
When it becomes clear that you're facing a prolonged dry period, it is important to moderate water usage giving consideration to the water you have on hand.
The Bureau Of Meteorology maintains detailed records of actual rainfall. In addition to the national Australian rainfall chart below, details of state rainfall can be downloaded. Further details are available at www.bom.gov.au
Join the free
online rainwater tank
||S Fenner WA
||J Van Der Hoeven QLD
||Fiona Rayns ACT