Irrigation

Freshwater from the desert

by Moutaz Ali

In depth

Model of the “Great Man Made River” irrigation project in Libya.

Model of the “Great Man Made River” irrigation project in Libya.

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Contrary to common belief, the most important riches of Libya are not the oil wells, but water. The world’s biggest reservoirs of fossil freshwater lie below its desert. Through an extensive pipeline system, these aquifers provide the country with water for consumption and agriculture. The so-called “Great Man-Made River” is the world’s largest irrigation project.

Libya’s Great Man-Made River (GMMR) currently transports almost 2.5 million cubic metres of water daily. It runs through an underground network of pipelines from the Nubian Sandstone Aquifer System in the Great Sahara desert to the coastal urban centres, including Tripoli and Benghazi. The distance is up to 1,600 kilometres. The GMMR currently provides 70 % of all freshwater used in Libya.

Except for the green and fertile strip along the Mediterranean coast, Libya is mainly a huge desert with a few scattered oases. Rain falls only on five percent of its surface. There is not a single river that would carry water the whole year round. Water scarcity has always been a huge problem.

The solution was found by chance when oil companies were drilling in the Libyan desert looking for crude in the 1950s. “They discovered basins containing huge amounts of water,” says geologist Zakaria Al-Keep. “It was fossil freshwater which had been stored underground for thousands of years.”

Libyan researchers were thrilled. They had been assessing various ways of obtaining drinking water. Options included the desalination of seawater or importing water from Europe by pipeline or ships. Now another possibility was to exploit fossil water resources from four underground desert basins: Sarir and Kufra in the south-east and Murzuq and Jabal Hasawanain the south-west. The idea of the GMMR was born.

On 28 August 1984, Muammar Gaddafi, the dictator who was toppled and killed in 2011, laid the foundation stone in Sarir. The plan was to drill 1,350 wells across the four basins.

Many of those wells are now operational. Most are more than 500 metres deep. They are connected to the coast by pre-stressed concrete cylinder pipes. Each pipe is seven meters long; the diameter is four meters. In total, more than 4,000 kilometres of pipeline have been built. They deliver over 6 million cubic meters of water per day. An additional 2,000 kilometres are planned.

The GMMR is the world’s biggest irrigation project ever. In 1999, the UNESCO awarded Libya a prize for notable scientific research regarding the use of water in desert areas.

The infrastructure is owned by the GMMR Project Authority. The primary contractor for the first phases in the Gaddafi era was the Dong Ah Consortium. Currently, the main contractor is Al Nahr. Both are domestic construction companies. Korean and Australian firms have supplied some technical parts.

So far, Libya has managed to build the GMMR without financial support from other countries or loans from banks. Taxes on tobacco and fuel contributed to mobilise money, and of course oil revenues helped. The total costs of the GMMR amount to more than $ 36 billion so far. By 2007, three out of five project phases were implemented, providing all major cities with water. Phase four has made good progress, but further construction was put on hold because of the revolution in 2011 and on-going civil war ever since. 


The Nubian Sandstone Aquifer System

Fossil water is stored in deep layers of the earth. Most of it has probably been there since glaciers melted thousands of years ago. The Nubian Sandstone Aquifer System (NSAS) is the biggest fossil freshwater reservoir in the world, estimated at 373,000 billion cubic metres, covering some 2 million square kilometres.

The NSAS lies under the Sahara desert, underneath the territorial lands of Libya, Chad, Egypt and Sudan. In 2013, the governments of these four countries agreed on a framework for joint management of the water resources, which have the potential to meet their growing water demands for a long time.

Careful management is necessary, however. Most likely, the aquifers’ water is not replenished by nature and will eventually be depleted. Accordingly, questions arise as to how long the resources will last. GMMR officials say that there so far is no decisive scientific proof of the origins of the water.

“In cooperation with different international institutions, we are measuring the level of the fossil water annually,” says Mahmud Abu Aisha of the GMMR. “We discovered that the level of the underground water drops by one centimetre in some years, which means nothing.” Surprisingly, however, the level actually rises in some years. His conclusion is that “there might be larger tributaries to our underground basins.”

GMMR officials reckon that Libya’s underground water could last for 650 years. Other experts claim the aquifers will be exhausted in 250 years. The default age of the pipelines, however, is 50 years. They must be renewed twice per century.


Agriculture and environment

Thanks to the massive freshwater flows from the GMMR, agriculture has become feasible also in desert areas. The government invested in seven big agricultural schemes. One is south of Tripoli, the capital. This project in the Jafara plains consists of 3,300 hectares, divided into 665 farms. These farms produce different kinds of citrus fruits, wheat, barley and vegetables. There were plans to plant millions of palm trees farther south, but fighting in recent years disrupted developments.

Environmental impacts should generally be assessed before a major project is started. Libyan law demands that this must be done. But it did not happen in the case of the GMMR, as Khalifa Elawej, an advisor to the General Board of Environment, points out. The political decision to start was taken in view of an “acute shortage of water”. At the time, the cost of fossil water was only a tenth of that of desalinated water. To date, no environmental impact assessment has been done.

According to Elawej, it is impossible to give an accurate account of the environmental effects because relevant data are unavailable. Lots of research would be needed. However, some impacts are obvious, he says. Positive impacts include:

  • The GMMR has helped to expand the green areas in the north and west of the country, stemming further desertification.
  • The green areas contribute to tempering the weather.
  • Traditional water resources in the north have been spared as people can now rely on GMMR water instead.
  • Agricultural production has increased.

There are downsides too, according to Elawej:

  • The desert environment of the areas where the fossil water is taken from may be changing.
  • The pipeline network itself may affect the environment.
  • Some of the water is stored in open pools, and evaporation leads to salinisation. Salinity of the GMMR water is high according to international standards, though it is not as bad as in the north’s traditional wells, which are affected by an influx of seawater.
  • Since most – and perhaps all – of the fossil water is not renewable, limited resources are being used.  


Destruction and sabotage

In the course of the civil war, the GMMR has suffered severe damage. During the revolution in 2011, NATO airplanes bombed water ducts in Brega. They also targeted a pipe factory, possibly in order to cut off Gaddafi’s forces from their water supply. More recently, sabotage actions took place in the south. In March 2017, the GMMR administration issued a warning that repeated assaults on wells at Jabal Hasawna might completely stop the water flow to Tripoli and other north-western cities.

Libyans are proud of the GMMR. But they also know that they depend on it. Urban people used to have only very limited access to drinking water. “I remember the years when my father used to drive for two hours to visit friends at the next oasis and bring back some gallons of fresh drinking water,” recalls Maia Ben Shaban, who lives in Tripoli. She has fond memories of the special day when the GMMR was linked to the city in 1996, substantially improving residents’ standard of life.


Moutaz Ali is a journalist and lives in Tripoli, Libya.
[email protected]

 

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e-Paper no. 6 2017, 2017/06, Page 38

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