The safe and efficient delivery of this clean water is jeopardized by aging infrastructure and increasing demands. Water distribution system rehabilitation and replacement decisions are generally prioritized based on risk. While strategies exist to manage risks of critical infrastructure failure, they do not fully account for social vulnerability. This paper presents a holistic assessment framework for the impacts of water distribution pipe breaks, considering the City of Vancouver, Canada, as a case study. This framework considers social, environmental and economic vulnerabilities as well as probabilities associated with pipe failure. The social vulnerability index (SVI) is obtained following application of a cross-correlation matrix and principal component analysis (PCA) to identify the most influential among 33 selected variables from the 2021 census of Canadian population at dissemination area (DA) level. The environmental vulnerability index (EVI) is obtained considering the combination of park and floodplain areas. The economic vulnerability index (ECI) is obtained from the replacement cost of pipes. The consequence of failure (COF) is then obtained by summing the three vulnerabilities with equal weights. Pipe probability of failure (POF) is evaluated by a Weibull model calibrated on real break data, as a function of pipe age. Risk is finally assessed by combining COF and POF for prioritizing pipe replacement and rehabilitation, with the final objective of mitigating the adverse impacts of infrastructure failure.
