Water utilities are increasingly considering the question of asset management within their priorities of investment. Firstly they define the needs within the operating staff and secondly they have to put in place funding and amortization practices in order to provide the sufficient means to fulfill the multiannual investments plans. Early warning in case of a break or a contamination and real time monitoring are similarly more and more developed in big utilities with the pending question of how much it costs and what are the benefits in term of performance and security. Such cost assessments are new in literature and can improve the crisis analysis methods and help resilience against extreme events.