Examining Water Infrastructure System Efficiency: A Unit-Based Analysis of Total Productivity, Partial Productivity, and Infrastructure Leakage Index in California and Georgia

Critical infrastructure systems are increasingly challenged by climate variability, aging assets, population growth, and operational interdependencies that threaten long-term system resilience and sustainability. Water utilities, as complex socio-technical infrastructure systems, require integrated performance assessment approaches that move beyond traditional component-level efficiency metrics toward holistic, system-oriented decision support frameworks. This study evaluates the relationship between unit-based productivity measures and infrastructure leakage performance across municipal water utilities in California (CA) and Georgia (GA) using data from the American Water Works Association (AWWA). The research applies a systems-based analytical framework to investigate how operational productivity, infrastructure leakage, and data quality interact within complex utility environments. By removing customer retail pricing effects from productivity calculations, the study introduces a unit-based methodology that better isolates operational system performance and enables more objective cross-utility comparisons. Statistical analyses, including Interquartile Range filtering and revised Infrastructure Leakage Index (ILI) calculations, reveal several significant positive relationships between productivity and water loss, challenging the conventional assumption that higher productivity inherently corresponds to greater infrastructure efficiency and resilience. The findings further demonstrate how inconsistencies in assumed loss variables and infrastructure reporting can distort system-level performance assessments and negatively influence infrastructure investment and management decisions. From a systems perspective, the results highlight the importance of integrated resilience analytics, data accuracy, adaptive management, and infrastructure governance in supporting sustainable utility operations. The findings contribute to the growing body of research on critical infrastructure resilience, data-driven infrastructure management, and decision-support methodologies for complex interdependent systems. This work provides practical insights for utility managers, policymakers, and infrastructure planners seeking to improve resilience, reduce non-revenue water loss, optimize infrastructure investments, and strengthen long-term sustainability outcomes within climate-affected and resource-constrained urban environments.