Cost analysis of the characteristics of a highly upgraded water supply system considering drought

Taking into account of shortage and pollution of raw water in the case of drought, an optimal design method of a water supply system with a buffer reservoir for raw water and advanced treatment facilities is proposed to fill a quantitative water demand as well as to meet a water quality requirement concerning hygienic safety and palatability. To minimize the sum of the construction cost and the operation cost of the system and to elucidate the characteristics of the system through the cost analysis, a formulation and a procedure to solve the optimization problem are given. A contour chart of the minimum cost of the system for various conditions of water supply is shown. The uncovered characteristics of the system and the contour chart are helpful to obtain the consent of water users to an introduction of the system.