Identifying Residential Water End Uses Underpinning Peak Day and Peak Hour Demand

Abstract

Accurate and up-to-date peak demand data is essential to ensure that future mains water supply networks reflect current usage patterns and are designed efficiently from an engineering, environmental and economic perspective. The aim of this paper was to identify the water end-uses which drive peak day demand and to examine their associated hourly diurnal demand patterns based on over 18 months of water consumption data obtained from high resolution smart meters installed in 230 residential properties across south east Queensland, Australia. Peak Day (PD) to Average Day (AD) ratios between 1-1.5 were driven by both external and internal end-uses. However, as the PD:AD ratio increased above 1.5, demand was driven largely by external water usage (i.e. lawn and garden irrigation).. Peak hour ratios (i.e. PHPD:PHAD) ranged from 1.3 to 3.0 for the four peak demand days. At the end-use level, the individual end-use category PHPD:PHAD ratios were in the range of 0.7 - 3.3 for all end-uses, with the exception of external or irrigation. The ratio for this latter end-use category was typically very high, at over 10 times the average irrigation demand. Comparisons with historically-based, but currently used, peaking factors used for network distribution modelling suggests that the degree and frequency of high peaking factors are lower now, due to the high penetration of water-efficient technology and growing water conservation awareness by consumers.