Abstract
There exists a trade-off between cost and redundancy in the design of water distribution networks, and some level of redundancy is not only expected but it is useful during critical periods. Further, it is important to consider the operation and repair costs while designing a network as there is a trade-off between the initial cost and the repair cost. In this research work, a new approach is introduced for sizing of water distribution pipes based on a performance measure and repair and replacement costs for the life period in addition to the initial cost. This study proposes a new performance measure based on power concept. The trade-off between performance and cost provides a guideline to decision makers for selecting a design from many alternatives. The optimisation model is solved using a differential evolution algorithm. The proposed model is applied to a benchmark network consisting of a reservoir, six demand nodes and eight links for two planning scenarios with 50- and 100-year design periods. This study shows the availability of good network configurations when repair and replacement costs are taken into account at the design stage.