This study examines the joint impact of random water consumption and emergency failures on water supply systems. Traditional reliability indicators are inadequate, as they overlook consumer-specific supply characteristics. The research develops integrated mathematical models to optimize system performance and proposes a method to calculate the probability of uninterrupted water supply to each consumer by considering all consumption and failure scenarios. The model enables reliability assessment for both individual consumers and the entire system, offering more realistic and operationally adequate evaluation and optimization tools.