Rainwater Tank End Usage and Energy Demand: A Pilot Study

Abstract

High resolution smart meters (i.e. 0.014 litres per pulse collected every five seconds) are being increasingly utilised for end use studies underpinning water demand forecasting and management strategies. An area that has not been examined is the impact of mandated internally plumbed rainwater tanks on water end uses and verification of potable water savings targets. This is a critical area for research given that a number of State Governments have mandated internally plumbed rain tanks to certain end uses (i.e. laundry, toilet and outdoor taps) for newly construction residential dwellings and projected savings are being included in urban water supply plans. Annually, in excess of 50,000 detached dwellings in Australia are being constructed with some form of internally plumbed rain tank configuration, predominately in the States of QLD, NSW and SA. However, the evidence to support the viability of set potable savings targets is based on non validated modeling and lacks field-based empirical support. Accordingly, this pilot study aimed to design an experimental method to determine the reliable supply of internally plumbed rain tanks across their supplied end uses and explore the influence of socio-demographic, environmental and appliance stock efficiency factors, on depletion rates. Moreover, it sought to design an experiment to reveal the rain tank pump energy intensity of individual end use events.