A significant man-made river project, believed to be the largest irrigation system globally, is set to undergo a new £5.1 billion development phase. The Great Man-Made River (GMMR) stands as a remarkable engineering achievement in the African desert, designed to transport ancient water to a dry North African country facing water scarcity due to its harsh climate.
Spanning the entirety of Libya, the Great Man-Made River Project aims to access “fossil water” from a vast underground reservoir known as the Nubian Sandstone Aquifer System (NSAS), which is believed to date back to the previous ice age.
Situated beneath the Sahara Desert and parts of Libya, Egypt, Chad, and Sudan, the NSAS is one of the oldest and largest aquifers on Earth, holding massive freshwater reserves. Libya discovered these aquifers while searching for oil in 1953, leading to plans for the GMMR emerging around ten years later in the late 1960s.
Funded by the late Libyan dictator Muammar Gaddafi, who referred to the project as the “eighth wonder of the world,” the GMMR reportedly had a budget of $25 billion (£18.5 billion). The enormous budget reflects the substantial amount of materials required to complete the project, with enough raw materials available to construct “20 Great Pyramids of Giza.”
The Great Man-Made River Authority (GMMRA) estimates the use of approximately five million tonnes of cement and steel wires long enough to encircle the earth 280 times. The project is divided into five major phases, with the first completed in August 1991, spanning 1,750 miles of functional pipelines and an additional 2,485 miles in various stages, boasting a daily water capacity of around 1.7 billion gallons.
As of December 2025, the fifth phase, nearing completion, is estimated to cost $7 billion and will extend coverage to rural and northern areas that are currently unconnected. Challenges faced during the project include setbacks from the 2011 civil war, leading to reduced public funding, power supply issues, infrastructure damage, and difficulties in importing spare parts.
The GMMR was developed to supply water to Libya’s densely populated coastal regions, offering a more sustainable option compared to the overexploited coastal aquifers and expensive desalination processes. The GMMRA describes the scheme as vital and strategic, serving as a potential solution to the water scarcity issue for drinking, irrigation, and industrial purposes in Libya.
Concerns over economic sustainability and the non-renewable nature of the resource have been raised, with estimates suggesting that water supplies could deplete within this century.