Increasing water stress, rapid urbanization, and climate change have turned sustainable water resource management into one of the most critical challenges of the current century. In this context, water reuse has emerged as an effective strategy for ensuring sustainable water supply and achieving water-sensitive cities. The present study aims to review global experiences in water reuse and identify the key factors contributing to the success of leading countries in this field.



This research adopts a review-based approach, utilizing qualitative content analysis. Data were collected from scientific articles, reports of international organizations, and relevant official documents. The experiences of selected countries were then examined through a comparative analysis.



The findings indicate that the success of water reuse programs is not solely dependent on treatment technologies; rather, integrated governance, appropriate laws and standards, continuous investment, water quality monitoring, social participation, and long‑term planning are among the most critical success factors.



Furthermore, an examination of the situation in Iran reveals that, despite relative development in wastewater collection and treatment infrastructure, challenges such as weak institutional coordination, infrastructure constraints, and a low share of water reuse persist.



Developing water reuse can play a significant role in enhancing urban resilience, reducing pressure on freshwater resources, and realizing the goals of water‑sensitive cities. Achieving this approach in Iran requires strengthening water governance, expanding infrastructure, upgrading technology, formulating national standards, and fostering public participation.