Plumbing the Sahara

LIBYA is one of the driest countries in the world, with only the narrow coastal region (less than 5% of the country) getting more than 100mm of rain a year. In 1953 the search for oil in the deserts of southern Libya led to the discovery not only of significant oil reserves, but also vast quantities of freshwater trapped in aquifers under the Libyan desert. The Nubian Sandstone Aquifer System, the world’s largest, is located under the eastern part of the Sahara desert and spans the political boundaries of Libya, Chad, Sudan and Egypt. It covers an area of just over 2m square km and contains an estimated 150,000 cubic km of groundwater.

Much of Libya's water supply used to come from expensive desalination plants on the coast, which left little water to irrigate land—vital in this largely desert country. Moreover the coastal aquifer historically used in Tripoli was becoming contaminated and its salinity was increasing. So in 1983 a massive engineering project, known as the Great Man-Made River Project, was created to supply water from desert aquifers to the coastal region for the majority of the Libya’s 6.3m people and to expand agriculture through irrigation.

The project, of which three phases out of five have been completed, is intended to supply 6.5m cubic metres of water a day through 4,000km of pipelines from 1,100 wells via five reservoirs at an estimated cost of $25 billion. The cost of this non-renewable water is approximately one tenth of the cost of desalinated water.