Reduction potential of potable water consumption at urban households: a case study in Sri Lanka

Availability of usable water resources in the Asiatic region is becoming scarce at a rapid phase, as consequences of urbanization and climate change. Therefore, saving drinkable water is an unarguably essential sustainable measure. This paper presents a case study done on domestic water-saving potential in urbanized areas of the western province in Sri Lanka. The study approached a mixed methodology. Randomly selected and stratified 342 residents participated in a semi-structured questionnaire survey which was conducted online and at the field. Qualitative and quantitative data on sociodemographics, water consumption and water-related behaviours, attitudes and awareness were gathered. Correlation–regression analysis was performed by using SPSS software. A mathematical model to forecast regular and optimized water consumption was derived. The water-saving potential was computed by subtracting the optimized consumption from regular water consumption. Results of the study indicated that the water-saving potential on average was 30%, which accounted for a substantial saving of resources used for supplying potable water to the urban households, from transboundary water resources. Ten experts in the water sector in the country were interviewed and six of them were given a special type of questionnaire based on analytical hierarchy process method, on water consumer's decision-making, in selecting a water-saving option, from given three options. Respondents used 55.2% criteria weightage in selecting rainwater harvesting as a feasible method in reducing potable water consumption, which was significant for an urban setting.