Integrating literature review into a conceptual framework for monetizing water reuse benefits

Abstract

Water crisis, driven by scarcity, pollution, and uneven distribution, threatens water security worldwide. Water reuse projects can contribute to sustainable water-management objectives by augmenting water supplies, reducing pressure on freshwater sources, and generating economic, environmental, and social co-benefits when implemented within appropriate hydrological, institutional, regulatory, and governance contexts. However, prevailing evaluation approaches often remain incomplete, emphasizing direct financial gains (e.g. avoided imports and cost savings) while undercounting broader benefits such as energy savings, greenhouse gas reductions, water quality improvements, and flood mitigation. This review addresses these gaps by synthesizing the full spectrum of quantifiable benefits associated with water reuse, organized across three dimensions: (i) economic valuation approaches, (ii) benefit categories spanning water supply, water quality, and flood mitigation, and (iii) sources of water to be reused. Following PRISMA guidance, we screened 7592 records retrieved from Web of Science and included 110 sources (74 peer-reviewed papers and 36 reports) that quantified or qualitatively evaluated reuse benefits. Results show that more than half of the included studies prioritize water supply benefits, while benefits tied to water quality and flood mitigation are comparatively underexamined and inconsistently monetized. Based on the evidence synthesis, we propose a conceptual framework that organizes water reuse benefits into major pathways and links them to measurable indicators, valuation methods, and aggregation considerations. We conclude by outlining research and practice priorities, including the systematic incorporation of water reuse benefits into economic evaluations to strengthen benefit accounting and support decision-makers in maximizing the value of water reuse investments.