Water Journal : Water Journal March 2011
refereed paper smart water systems & metering water MARCH 2011 95 Table 1 shows that replacing low-efficient with high-efficient shower-heads could provide household savings of at least 13kL/ hh/a (or over 25%), lower than reported by Willis et al. (2009b); however, the percentage of householders that were reported to have high-efficient/low-flow showerheads in this study was over 70%. Additionally, shower consumption for this study was lower than several of the previous studies, including Willis et al. (2009b), suggesting that the margin for savings will be less as the technology has already been widely adopted in the SEQREUS sample. End use patterns and socio-demographics End use comparisons were made between different household types. Households were grouped into single (1 person), adult household (2 people), small family (eg, 2 adults and 1 child), medium family (eg, 2 adults and 2 children) and large family (5 or more people). The water consumption pattern for a single household shows a relatively even consumption across all end uses, with a growing trend for higher clothes-washer, shower and tap use as the households become larger (Figure 8). Bathtub use is also apparent mainly in the households with families. On a per capita basis (Figure 8a), larger families are typically more water efficient than smaller households, whereas the opposite is typically found on a per household basis (Figure 8b). Analysis also showed a trend for higher-income families to have larger households but use relatively less water than lower-income, smaller families (data not shown). There was a noticeable tendency for older householders to use more water. Although neither relationship was statistically significant, this may reflect the likelihood of the occupants of a higher income household to be away from home for greater periods, when compared to low income groups such as single parent families and pensioners. Willis et al. (2009b) found no significant differences between water consumption across four different socio-economic groups, although the higher-income group used the least volume of water during the period of analysis. Conclusions The water end use consumption reported for this study confirms the anecdotal and government reporting of a shift towards lower residential water consumption post-drought in SEQ. The attitudes and water use behaviours of people have generally moved toward a more conservative approach to water use. This increased awareness, together with ongoing water conservation measures for much of SEQ, was likely to maintain a generally low consumption rate of water during the winter of 2010. A summer 2010/11 end use sample will enable better understanding of seasonal influences on water end uses, particularly irrigation. Water demand management key points for stakeholders in this project include: • Non-compliant irrigation between 10am and 4pm, particularly for homes in the Sunshine and Gold Coasts; • Water-efficient fittings for showers and taps continue to provide a least-cost water demand management option for conserving water; • Changing to water-efficient washing machines significantly reduces household consumption; and • A trend for higher per capita water consumption for older, lower income, smaller-sized households. Future Reporting End use analysis will also be completed for other seasons (for example, summer 2010/11) where more detailed analysis and discussion will cover: • Comparative assessments between clustered samples based on demographics, households with different fixture/appliance star ratings; • Water end use diurnal patterns; • Analysis of leakage volumes and leak typology patterns; and (a) Per capita end use consumption (b) Per household end use consumption Figure 8: Average end use consumption for different household types.
Water Journal April 2011