Forecasting residential water demand: Case study

A new daily time series model for East Doncaster, Melbourne, Australia, is being evaluated. The model depends on the postulate that total water use is made up of base use and seasonal use, where base use is characterized by the water use during winter months and seasonal use on seasonal, climatic, and persistence components. Using the daily data collected by Yara Valley Water for East Doncaster water supply distribution zone and the corresponding rainfall and temperature data from the Bureau of Meteorology from 1990 to 2000, the base values were calculated based on the lowest months of water usage in a year and were correlated with the day of the week and temperature and rainfall. Results revealed these three factors to be statistically significant and therefore, base use to be climate dependent. The seasonal water use is modeled by a series of three equations. The separation of the random component from the climatic variable resulted to a better R-2 of 86%. The model is further validated using different set of data from 2000 to 2001 yielding a R-2 of 86%.