COST-EFFECTIVENESS ANALYSES OF LIBYAS WATER-SUPPLY SYSTEM

This paper summarizes the methods and results of economic analyses per formed for the agency responsible for water supply development and ope ration in Libya in support of decisions regarding further investments in water supply systems in their country. This study identified least- cost combinations of investments in Libya's Great Man-made River Proje ct (GMRP) together with desalination that would meet specified water d emand targets at various demand sites in the country. The GMRP is one of the largest civil works projects in the world, involving the pumpin g of ancient ground water from the Sahara Desert and transporting it h undreds of kilometers to the coast of Libya where demands for water ex ist. The paper outlines the optimization models used in these analyses and presents some interesting outcomes that warrant additional studie s focusing on capacity expansion over time. Given the investments alre ady made in the GMRP, only under most optimistic cost scenarios does d esalination appear to be an economically efficient expansion alternati ve and then only for a limited range of water demands.