Reprint of the Special Issue 'Water Supply System Reliability, Safety and Risk Modelling & Assessment, Volume II' (Water, ISSN 2073-4441). The volume gathers peer-reviewed contributions on reliability and safety of water supply and distribution infrastructures considered as critical infrastructure. It covers methods for risk modelling and assessment, leakage and failure prediction, human factors in operation, energy and life-cycle aspects of system design, and treatment performance studies. The collected papers provide data-driven and model-based approaches that support climate-resilient planning and robust operation of water utilities.