A model for optimal design of reliable water distribution networks

A reliable water distribution network must have sufficient capacity to provide desired levels of service to customers, not only under normal operating conditions, but also under prescribed failure scenarios, e.g., failure of critical mains, This paper describes a model for optimal design of reliable water distribution networks. The inherent uncertainty in the nodal demands and the values of pipe coefficients, as well as the impacts of component failures, are able to be considered in the model. A probabilistic hydraulic model is used in the model to account for the uncertainties in nodal demand and pipe capacity. First order reliability method (FORM) is used to compute approximate values of the capacity reliability of water distribution networks. The water distribution network designed by the model is capable of providing a prescribed level of service in terms of water quantities under random demands and random pipe capacities under the normal network configuration, as well as under degraded network configurations with prescribed failure scenarios.