Do resilience metrics of water distribution systems really assess resilience? A critical review

Having become vital to satisfying basic human needs, water distribution systems (WDSs) are considered critical infrastructure. They are vulnerable to critical events such as extreme weather, natural and man-made disasters, armed conflicts etc. To account for critical events during design and operation of WDSs, the concept of resilience is frequently mentioned. How resilience of WDSs can be assessed using resilience metrics has been the subject of research of many publications. The aim of this paper is to inspect the alignment between a general understanding of resilience in WDSs and the metrics used for their resilience assessment. A novel framework for categorising resilience metrics for WDSs is presented. A literature review of resilience metrics for WDSs is performed and the results are analysed using the developed framework. The results show that the existing resilience metrics are not able to capture resilience in its complexityresilience metrics do not really assess resilience of the WDSs as a whole, but rather focus only on specific functions and properties which can make the WDSs resilient.