Rainwater harvesting is growing in importance nationally in a scenario where household and industrial water prices have doubled during the past 10 years with no increase in volume consumed.
This was the view of Rainwater Harvesting Australia which hosted an audience of water specialists and engineers at a professional breakfast in Perth on Thursday, May 10.
After the event, committee member Michael Smit said as rainwater falls on roofs, it is an efficient water source, it needs minimal treatment with no transportation cost and it is economically efficient to use before mains water supply in urban areas.
“Nationally one in four houses in Australia have rainwater tanks,” Michael Smit said.
“Rainwater is a clean water choice. Two million Australians drink rainwater every day and the supply is simple to treat through good design.
“Rainwater harvesting works well in Perth. Gardening Australia presenter Josh Byrne uses rainwater as his main source of internal water for nine months of each year.
“Chairman of Irrigation Australia Andrew Ogden did some insightful analysis of daily rainfall data during the past 12 years showing that 50 per cent of Perth rainfall events over 3mm occur outside winter.”
WA Water Minister, Dave Kelly, told the breakfast that Perth relies heavily on desalination and groundwater to meet its supply needs and is seeking to underpin sustainability by promoting household water efficiency.
While desal provides security, it is expensive and it would be logical to use rainwater from the roof when it was available and cost effective, he said.
According to Mr Smit, Mr Byrne is described as being arguably the best speaker on sustainable water use nationally and his ability to describe the vision to reality at the residential scale and on a neighbourhood scale is inspiring.
Chairman of Irrigation Australia Andrew Ogden delivered a carefully considered and intelligent grounding on the context for rainwater harvesting and irrigation in Perth.
The presentation included the hydrological cycle, irrigation legislation in Perth, a positive assessment of the local rainfall pattern for urban rainwater harvesting supply for internal household use in Perth and an important commentary on the need for management of the 180,000 unregulated garden bores in Perth.
