Analysis of the feasibility of interim water supplies

Abstract

The general problem of the feasibility criteria for interim water supplies is analyzed. Two forms are presented: (1) a combination of an interim supply and a long‐term supply and (2) the possibility of multiple interim supply projects and a long‐term supply. Both forms are compared with an immediate long‐term conventional water system. A problem formulation that yields to the optimal deferment period of the long‐term supply system is presented. The cost effectiveness of a combined desalting‐surface supply system is discussed, and a numerical example is presented. A table relating the different costs of the interim and long‐term projects with the water requirement is calculated. This table provides the optimal deferment period for the long‐term projects. The numerical results show that although the desalting system described clearly would not be competitive as a complete substitute for the surface system, the combination system of desalting for 10 years followed by the surface system is fully competitive.