AbstractA methodology for assessing the seismic risk in a WDN is presented here as obtained from the analysis of network mechanical reliability when pipe failures are due to earthquakes. The mechanical reliability analysis is performed considering WDN topological changes subsequent to multiple failure scenarios; while pipe failure probability law is brought from the American Lifeline Alliance that assumes empirical vulnerability functions derived from data collected during recent earthquakes in the Pacific area. A multi-objective optimization is run to explore the space of contemporary pipe failures which may occur during an earthquake. The method is applied and discussed using C-Town network.