Optimal upgrading of hydraulic-network reliability

A least-cost methodology is presented for use in upgrading existing single-source water-distribution networks in order to sustain any single component failure (link or node). The methodology is developed by casting the network-reliability problem in terms of an explicit level of system redundancy. As a result, minimum cut set computations are avoided as well as the need to select an arbitrary level of system reliability. The design engineer can thus select a design based on the total cost and the desired level of service. The proposed methodology results in a network that provides two different levels of system redundancy: Topologic and hydraulic. Topologic redundancy is satisfied through the application of methods from graph theory. Hydraulic redundancy is satisfied through the application of linear programming. Application results are presented for the Federally Owned Water Main System in Washington, D.C.