Rapid estimation of rainwater yield throughout Australia and review of Queensland rainwater harvesting operating policy

Rapid estimation of rainwater yield throughout Australia and review of Queensland rainwater harvesting operating policy

Rapid estimation of national rainwater yield for low and high performance scenarios is derived using Taylor's Hyetal Index (THI). Stochastic representations of the modes of failure of rainwater harvesting (RWH) systems is the foundation of THI. THI holds a strong regression to RWH performance for 7,000 variations in the national residential built environment (r2 = 0.96). A small subset of 34 variations is presented in this summary paper. THI is based on inspecting daily rainfall data from the Bureau of Meteorology, which enables rapid and accurate rainwater yield estimation at potentially any location throughout Australia. A review of the Queensland RWH mandate, using THI, has demonstrated many locations can achieve or are close to achieving their water saving targets. The worst performing region is South East Queensland, which is also an area of high population and municipal water demand. This region is also able to significantly exceed their water saving target, when adopting a RWH system beyond the mandate. Therefore, with changes to the mandate, Queensland could increase their renewable natural capital and societal and environmental benefit

Authors retain copyright.
The winner of the 2010 National Student Environmental Engineering and Sustainability Award is Ben Taylor from the University of Southern Queensland. Ben's paper was titled 'Rapid Estimation of Rainwater Yield Throughout Australia and Review of Queensland Rainwater Harvesting Operating Policy'. This research developed a rapid estimation of national rainwater yield for low and high performance scenarios using Taylor's Hyetal Index.

The approach identified South East Queensland as an area unable to meet its water harvesting target through application of the current Queensland rainwater harvesting mandate. The analysis indicated that this area would be able to meet the target through modification of the rainwater harvesting mandate to increase the effective catchment of water tanks and expand reuse requirements.

Mr Taylor will be presented with the 2010 Award at the National SSEE Conference in Brisbane in October 2011 where he will also present his paper on the project.