Composite Index of Water Environmental Sustainability (ICSA): Evaluation of Municipal Performance in the UPGRH SF1

Objective: The objective of this study is to develop and apply a Composite Hydro-Environmental Sustainability Index (ICSA) to the municipalities of the Water Planning and Management Unit of the Tributaries of the Upper São Francisco River (UPGRH SF1), aiming to assess municipal hydro-environmental performance in an integrated manner based on multiple dimensions. Theoretical Framework: The research is grounded in the concepts of water governance, integrated water resources management, and composite indicators, based on internationally consolidated methodological guidelines, particularly regarding the construction, normalization, and aggregation of multidimensional variables applied to environmental sustainability. Method: The ICSA was structured using 14 subindicators organized into five analytical dimensions: institutional governance, sanitation and pollution control, environmental conservation, information and monitoring, and environmental education. Data were obtained from official sources (SNIS, IBGE, ANA, IGAM) and normalized on a 0–100 scale. The index was calculated using the arithmetic mean of the dimensions, with equal weights, and analyzed through comparative and spatial approaches. Results and Discussion: The results revealed significant heterogeneity among SF1 municipalities, with strong influence of institutional capacity on environmental performance. It was observed that the absence of information systems and planning significantly compromises hydro-environmental sustainability, regardless of existing infrastructure. Research Implications: The study contributes to water resources management by providing an integrated tool for territorial assessment, with potential application by watershed committees and environmental agencies in planning and monitoring public policies. Originality/Value: The main contribution lies in the integration of multiple dimensions into an index applied to real data, enabling comparative assessment and supporting decision-making at the municipal level.