Libya's choices: Desalination or the Great Man-made River Project

At the beginning of the 1980s Libya decided to develop the Great Man-made River Project (GMRP) to provide water to its population. The GMRP is one of the largest civil engineering projects in the world, involving the abstraction of ancient groundwater from the Sahara Desert and the transportation of water over hundreds of kilometers to the coast of Libya where demands for water exist. In support of decisions regarding further investments in Libya's water supply systems, an economic analysis has been performed. This article summarizes the methods and results of the study. The study identified least-cost combinations of investments in the GMRP together with desalination that would meet specified water demand targets at various demand sites in the country. The results indicate that, due to the investments already made in the GMRP, desalination only appears to be an economically efficient expansion alternative under most optimistic cost scenarios for desalination plants, and then only for a limited range of water demands. Another interesting finding is a significant uncertainty concerning well field capacity scheduling over time, a finding which warrants additional studies focusing on capacity expansion over time. In addition to economic aspects, information on other water related issues and viewpoints seems to be very relevant to decision making on the future of Libya's water supply situation as well as to other large scale water conveyance projects.