Modelling household water use: Using empirical data to inform continuous simulation

Abstract

In recent decades traditional water management practices have come under stress from rising global populations and changing climate conditions. The prohibitive costs of upgrading centralised infrastructure networks to meet these changing conditions has encouraged research into the provision of integrated water management at the site scale, such as rainwater harvesting (RWH) or greywater re-use. Unfortunately, effective design, implementation and optimisation of these strategies has been restricted by uncertainties when quantifying how these systems will perform on each site. The reason for this difficulty is that there are many aspects of household or site scale hydrology that are poorly understood or difficult to model, including residential outdoor water use and garden watering. The accuracy and speed at which these aspects of site hydrology can be modelled is a vital consideration in the development of site scale water management. This study aimed to improve the understanding surrounding the accuracy and usability of different strategies for modelling the interaction between the different household water uses. This will provide insight into how their effect upon site scale hydrology can be quantified in future studies and improve the design and optimisation of new integrated water management strategies. This was achieved by analysing four different strategies that each apply different assumptions to account for the three main end uses of household water use (indoor, garden watering and other outdoor water uses) that have been utilised or suggested by previous researchers for use within continuous/water balance simulations. These four strategies were each tested using historic water use data from 100 residential properties in Melbourne's eastern suburbs.