Strategic decision making for urban water reuse application: A case from Thailand

Planned and implemented water reuse (WR) is an eco-efficient way to reduce water stress and improve sustainable water management. However decision making systems have been typically devoted to its economic and technical aspects, with less consideration of indirect impacts and sustainability, and have been mostly limited to landscape irrigation option. Thus, this study's objective is to create a strategic decision making system (DMS) incorporating multiple criteria, available alternatives, and environmental externalities for urban WR application. This study adopted a system development process including analyzing existing systems, developing a DMS, and applying the system based on a case of Pattaya City (PC), Thailand. Specific techniques, e.g. multi-criteria decision making, were used to conduct and/or analyze data from secondary sources, together with interviews of key informants and questionnaire surveys of households. The developed DMS can provide a new set of criteria encompassing multiple aspects and externalities, and their relative importance for strategic decisions on WR application. This DMS was proven to be a straightforward method for giving not only an appropriate application but also the strengths and weaknesses of the alternatives. Applying this DMS could contribute to proper strategies to WR management, and to be an accessible tool for communicating with stakeholders.

Research Highlights
► This paper proposed a decision making system (DMS) for water reuse application in Thailand.
► A new set of criteria covered economic, environmental, social, and technical aspects including externalities.
► The results of DMS applying in the studied city suggested that industrial uses provided an appropriate alternative for WR development in the current situation and uncertainty from increased water demand and tap water price.
► This study contributes to improved decision making mechanism, a thorough understanding of related stakeholders, the identification of new set of decision criteria and their importance order and feasible WR alternatives.