Water Supply System Models with Capacity Expansion

An optimization model for designing an economical regional water supply system, which consists of water production and water transmission facilities, is presented. Water demands are assumed to be increasing over a planning horizon and to be satisfied from several potential supply sources. In this study, a method has been developed to determine a water supply system layout and to size water production and transmission facilities. A two‐phase heuristic optimization technique is used to solve the models formulated. A Phase I model selects a system layout, along with capacities in a transmission and source system subject to constraints on water availabilities at potential sources and on increasing water demands. The Phase II model determines facility components, pumping locations, and capacities and pipeline diameters for the transmission system using Phase I model solutions. The methodology is applied to a region in northeastern Illinois.