Defining domestic water consumption based on personal water use activities

Abstract

As the world increasingly faces water shortages, it is critical to develop realistic estimates of water consumption based on water-use activities rather than top-down imposed limits. This study quantifies the absolute basic consumption (ABC) of an individual, irrespective of water-use location or water source, with a focus on personal water-use activities rather than measured household consumption. A theoretical model to stochastically describe 21 personal water-use activities was developed, corresponding to lifestyle levels based upon Maslow's hierarchy of physiological needs. From this model, the expected value of ABC was 92 L/capita/day (LPCD) and includes restrictions on several everyday activities and thus would be better as a minimum target during stringent water restrictions. A more realistic expected value for non-wasteful, indoor-only water use was determined to be 175 LPCD. The results of this study serve as a useful benchmark to inform policy choices and efforts to conserve water without affecting health and wellbeing. HIGHLIGHTS It is important to quantify water consumption based on water-use activities and across all daily water-use locations.; The expected value of basic water consumption for a healthy urban lifestyle is 92 L/person/day, which includes restrictions on everyday activities.; A more realistic expected value for water consumption is 175 L/person/day across all water-use locations during a typical day.;

Keywords

• drinking water
• stochastic model
• sustainable urban development
• water consumption
• water demand
• water-use activities