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. HIGHLIGHTS Residential water end-use in some places in Sri Lanka was investigated.; People in the capital city use more water than those in the regional city.; Toilet, kitchen, clothes washing, and bathing water usage varied based on region.; Tap water supply alone may not be sufficient to meet increasing water demand.; Rainwater acceptance was influenced by the knowledge level about its specific use.;