Optimal Expansion of Water Distribution Systems

A method for the optimal expansion of water distribution systems subjected to a single loading pattern is developed. The method optimally decides the pumping heads at new source nodes, if any, and also optimally selects the links which need strengthening to improve the delivery capability of the existing system. The method is iterative and converges rapidly to a local but fairly good optimal solution. Optimization of an entirely new distribution system is a particular characteristic of this general approach. Examples of the method are given, including its application to the expansion of the New York City water supply tunnel system. The possible extension of the method to time‐varying demand patterns is also described.