Author(s): Graham A. Jenkins
Linked Author(s):
Keywords: Rainwater tank; Economic analysis; Hydrologic effectiveness; Climate variability; Continuous rainfall simulation; Yield analysis; Integrated Urban Water Management
Abstract: Household rainwater tanks form part of an integrated urban water cycle management system which is a key aspect of the water sensitive urban design philosophy. They provide scope for harvesting rainwater for domestic uses, as well as mitigating the impacts of urbanisation on catchment runoff. This paper describes the application of a continuous daily water balance model of a roof and rainwater tank system. The model has been applied to 15 hypothetical houses located at a range of sites throughout Australia. The model has been applied for a range of water consumption scenarios and different rainwater tank volumes. The study has shown that although larger volume tanks produce the highest yield, a smaller tank may be an optimum, based on the minimum unit cost of rainwater supplied to the household. The hydrologic effectiveness of the rainwater tank system is an important factor in determining the yield for a particular system. The hydrologic effectiveness of the system is affected by the monthly variation in rainfall, the median annual rainfall and the consumption pattern adopted. Uniform rainfall patterns and uniform consumption patterns produce a larger yield than highly variable patterns. This may have significant consequences on the suitability of rainwater tanks in terms of the potential effects of climate change.
Year: 2007