Optimizing Hydraulics and Water Quality in Water Distribution Networks Using Genetic Algorithms

This paper presents a total social cost framework for optimisation of the design and operation of water distribution systems, including water quality considerations. The objective function includes the traditional capital and operating costs of the infrastructure. To this are added the social costs associated with waterborne diseases, the risk of cancer due to disinfection byproducts and a cost due to poor aesthetic quality of the water. In this paper water quality is considered purely in terms of levels of disinfectant (chloramine and chlorine) throughout the system. A case study for Yorke Peninsula in South Australia is analyzed. The results from the case study illustrate the need to consider seasonal variations and their impact on water quality levels in addition to the traditional peak hydraulic loading conditions. The genetic algorithm optimization models used to solve this problem are quite complex and require long run times. Ways of reducing this complexity need to be explored in future studies.