Estimating Costs Model of Dual Water Supply Systems

Abstract

A mixed integer programming model is used to generate the optimal design of dual water supply systems. The water‐supply network is of branched, or nonlooped, type, and the model selects discrete pipe sizes as well as optimal capacity and location of pumping stations. A distinct feature in the formulation of the model is that it takes into account the spatial and temporal variability of the water demand through a nonlinear relationship between the design flow and the area to irrigate. The model is applied to a hypothetical example and its superiority to a nonlinear model is demonstrated. A real‐world application is demonstrated and the model is then used in a regression analysis to determine if simpler cost relationships can adequately simulate the cost of dual water systems. Applications of the regression equations to three realworld problems confirm the reliability of the method, with errors between observed and generated costs not exceeding eight percent. Limitations of the regression model are also discussed.