South East Queensland Residential End-Use Study: Stage 2 final report and summary of water consumption trends from 2010 to 2014

Abstract

A range of total and end-use water consumption trends and analyses have been presented in this report, which is a culmination of over four years of ongoing smart metering of a sub-sample of up to 250 South East Queensland homes. End-use analysis and total water use trends for the sample of residential homes in SEQ have indicated a potential rebound in water consumption – particularly outdoor use. On the whole, consumption fluctuated more markedly in the last two years (e.g. 2012 onwards) compared to the first two years of measurement. This may be related to the permanent water conservation measures (PWCM) that were current for the post drought period up to the end of 2012, resulting in a situation where people’s outdoor water usage was less likely to be influenced by the weather conditions and more likely to be influenced by the recent drought and severe water restrictions, and a subsequent continued reluctance for high water use outdoor activity. Thus, it is difficult to determine whether the observed increase in average consumption post-drought and post-floods is a result of a rebound to a “new normal” average use with the absence of social and behavioural cues to conserve water, or if it is skewed by natural variation in use prompted by periods of dry, warm weather which have coincided with elevated outdoor use. Further water consumption data will assist in confirming the conclusion here that while water use has rebounded from the mid-drought low of ~ 130 L/p/d, it is highly unlikely that average water consumption will ever reach the >250 L/p/d that was observed pre-Millennium drought, due largely to permanent shifts in people’s water use behaviour (especially outdoors), the mandated water-efficient fixtures in new developments and the growing number of smaller lot sizes and multi-unit dwellings. As demonstrated in this report, using behavioural interventions, in combination or as a substitute for the often unpopular water restrictions, may be a useful approach in changing the daily peak demand patterns; thus reducing the pressure on network pumping energy costs during these peak times. In the absence of immediate threats to water supply, the approach of using demand management to optimise water network infrastructure operating costs may well shift more strongly into focus in the near future.