Status and perspectives of sustainability indicators applied in the water sector

This review examines 74 original articles published between 2023 and partially 2026 in the Scopus database, focusing on how sustainability indicators are conceptualised and applied to support circular economy transitions in the water sector. Recent literature shows a rapidly expanding suite of assessment tools, ranging from life cycle and circularity metrics to indicators of water productivity, resource recovery potential, wastewater reuse efficiency and governance-oriented frameworks embedded in Water-Energy-Food-Environment nexus approaches. Emerging trends point toward increasingly multidimensional and integrated indicator systems, yet ongoing challenges, such as energy-circularity trade-offs, fragmented regulatory environments and difficulties in adapting indicators to diverse socio-economic and ecological contexts, limit wider implementation. The review highlights priority directions for advancing the field, including the development of harmonised yet flexible indicator sets, stronger alignment across governance levels, and the wider adoption of digital monitoring tools to enable real-time assessment and evidence-based decision-making in circular water systems.