Availability and public acceptability of residential rainwater use in Sri Lanka. (10th October 2019) - Takagi, Kaori
Abstract: Rainwater is one of the alternative water sources that can potentially replace municipal water supply, particularly in areas with insufficient water supply, such as developing Asian cities. In this study, we consider both the acceptability and availability (i.e. amount) of rainwater use in Galle, situated in the southern part of Sri Lanka. We examined the specific acceptability of each end use through a questionnaire survey. The survey results indicated that the acceptability of non-contact and non-intake uses, such as outdoor, toilet, and laundry uses, was high. To improve acceptability, we provided information on quality, quantity, and cost. As a result, the acceptability of using rainwater for toilet, bath, and washing could be significantly improved, particularly since people who considered it unacceptable tended to change their attitude to acceptable. In addition, we estimated the availability of water rainwater harvesting using probabilistic simulation. Finally, we found that by introducing a standard-sized water storage tank, the toilet water demand of 90% of four-person families can be satisfied by rainwater. Highlights: The rainwater acceptability of non-contact and non-intake uses was high. Information on rainwater quality, quantity, and cost improve the acceptability. Particularly, people considering rainwater unacceptable changed their attitude. Toilet water of 90% of four-person families can be satisfied by rainwater.