To quote Colin Nash, the champion Chairman of the Rainwater Harvesting Association, “The gun has gone off”, we are not waiting for the start anymore, we are up and running.
The Australian Bureau of Statistics has been working closely on rainwater harvesting since their big report on the subject in 2013 Environmental Issues: Water use and Conservation. Now the ABS has estimated the contribution rainwater makes to household water use in the whole of Australia in 2013/14, and it is significant. Most readers of this blog already know rainwater makes a big contribution, but rainwater has been dismissed by most government water experts for the last decade. This report is independent data showing rainwater is making a difference, both in the country and in the cities. There is a possibility that to ignore this report could be professional negligence.
So how much rainwater does the ABS estimate is being used each year? 156 billion litres. That is 8% of total household use. The equivalent value is $507 million. Rainwater provided more water than desalination in 2012/13. Rainwater is a major stakeholder in both water management and household economies. It is important to say the RHAA estimate is actually 247 billion litres, but the ABS acknowledges they are still working on their estimation process.
The ABS estimated rainwater storage capacity is 8 billion litres. A big dam like the Thomson or Wivenhoe holds 100 billion litres so 8 billion litres does not sound like that much. But you have to appreciate that rainwater tanks fill up every time it rains and empty every time they are used. A well used tank connected to a large roof could realistically fill up 50 times in a year, giving a potential storage of 400 billion litres. And we are just getting started, this is a major potential storage.
That $507 million equivalent value is an interesting figure. That is the figure householders would have paid if they had paid their water utility for the rainwater they used at the same rate as utility water. In Queensland, households saved $149 million, more than 10% of the total expenditure on water. This is also the revenue that water utilities potentially lost because of rainwater. I have friends who consider that to be the reason that rainwater is ignored in water strategies.
Are state governments actually in a position where they have to choose between household savings and water utility revenue? No, they are not. The RHAA research by Dr PJ Coombes et al shows that the lost revenue from rainwater is LESS than the long term operational savings of providing less water. Now that we are vindicated on how much water is coming from rainwater tanks, maybe utilities, regulators and government could take a closer look at the real savings.
And check out our Press Release – $500 million of water from rainwater tanks as Governments ignore rainwater harvesting