Assessing the resilience of water and wastewater utilities: A multi-criteria approach for Chile

Ensuring the operational resilience of water and wastewater utilities (WWUs) is critical for safeguarding public health, environmental sustainability, and service continuity in the face of natural and human-induced hazards. This study develops an innovative Operational Resilience Index (ORI) to comprehensively assess WWU operational resilience from a regulatory perspective. The ORI integrates multiple resilience indicators across three key dimensions—service performance, asset management, and water security—using a Multi-Criteria Decision Analysis (MCDA) approach, incorporating expert and stakeholder preferences through the Best-Worst Method (BWM). The methodology is applied to 29 WWUs in Chile, a country with high exposure to natural disasters. The weights assigned to resilience indicators indicate a preference for short-term service performance over long-term infrastructure resilience. The estimated ORI values range from 0.524 to 0.808, with the maximum achievable score being 1.000. It was evidenced that asset management represents the most critical area for improvement, indicating a need for regulatory incentives to promote infrastructure renewal. While no statistically significant differences in ORI scores were found based on WWU ownership structure (public, private, or concessioned), concessioned WWUs demonstrated statistically superior performance in asset management (p-value = 0.012), underscoring the need for targeted regulatory measures to strengthen this dimension in other ownership models The ORI provides a systematic benchmarking tool for regulators, enabling resilience-based performance assessments and targeted policy interventions.