Demand-side water management using alternative water sources based on residential end-use

Demand-side water management in developing countries should ideally involve controlling the use of piped water supply and securing water sources that complement it to ensure sustainable use. To investigate the feasibility of incorporating these factors, we conducted a survey in Galle, Sri Lanka. First, an end-use survey was conducted to understand current and near future water use. The results indicated that the toilet, kitchen, clothes washing, and bathing related per capita water consumption in Galle was significantly lower than that in Colombo. The results also suggested that increases in indoor water needs cannot be supplemented via piped water supply only; it is necessary to consider alternative water sources, such as rainwater. Second, the residents' acceptance of rainwater usage for each indoor use was surveyed and it was found that acceptance depended on knowledge levels regarding rainwater harvesting.