Water supply planning simulation model wing mixed-integer linear programming ''engine''

This paper presents a simulation model to be used for water supply planning by a metropolitan water utility, Water supply operations for a single, monthly time step are formulated as a mixed integer linear program (or more simply, LP). The LP is then embedded in a month-by-month simulation model, The LP is formulated using a priority-based objective function, The model has been used successfully by the Alameda County Water District (California) staff for its long-range, integrated planning. The model also shows that some of the inherent weaknesses of math programming in general and mixed integer linear programming in particular, can be overcome to build a successful model.