Water expert: Desalination or displacement for Sana’a residents [Archives:2006/958/Health]

June 26 2006

By: Ismail Al-Ghabiri
and Amel Al-Ariqi

Since the 1990s, Sana'a basin has become a major preoccupation, as studies, statistics and experts warn that the water crisis in Sana'a is beginning to take on a catastrophic nature. Other experts expect the basin will drain away by 2010 if necessary measures are not taken to stop the current water consumption rate that is unparalleled with the basin's water resources.

Since that time and until now, Sana'a has hosted many Yemeni and foreign experts and officials who have arranged conferences, seminars and workshops tackling the Sana'a basin issue in an attempt to come up with solutions to this problem.

Sana'a University recently hosted a delegation from Trans-Mediterranean Renewable Energy Cooperation (TREC). Along with Yemeni experts, the delegation arranged a scientific seminar wherein they brought up the ability to employ desalination technology to solve the Sana'a water crisis.

Crisis becomes disaster

Water supplies historically were obtained by digging wells and tapping streams. Agriculture in the Sana'a basin, a central highland area of approximately 3,200 sq. km., depended upon dry farming practices and rain-fed irrigation.

However, in the 1960s and increasing rapidly from the mid-1970s onward, many aquifers were discovered. Boreholes were drilled to tap groundwater and pumps were introduced for irrigation and domestic usage. Gradually, there was uncontrolled extraction by private wells. According to available statistics, the total number of wells in Sana'a basin is 60,000 and Sana'a withdrawals exceed renewable resources by 400 percent.

Moreover, Sana'a basin is home to approximately 1.8 million people, of whom one million live in the capital city while the rest live in surrounding villages. (Incidentally, Yemen's annual growth rate is 3.02 percent.) These residents depend on underground water resources estimated at two to three billion cubic meters, with such quantity used in three main ways. Sana'a residents annually consume nearly 250 million cubic meters, 80 percent of which is for agriculture (of which the majority is used to irrigate qat), with 20 percent consumed by daily use and industry.

The Sana'a water basin gradually is running out, as the water level decreases approximately five to six meters every year. This is considered a danger, especially in coming years because there is no new provision for underground water, according to experts.

“Do we have a water problem in Sana'a? Is it a minor one, a large one, a crisis or a disaster? My answer: it has the nature and scale to become a disaster,” Dr. Hussein Al-Towaie said, describing the Sana'a basin situation.

Desalination or displacement

According to Al-Towaie, the Sana'a water crisis causes residents to use unreliable domestic water supplies, as the National Water and Sanitation Authority (NWSA) supplies only 30 percent of the urban population. Additionally, only 30 percent of rural populations have access to safe drinking water and water resources are being overdepleted as well.

TREC Coordinator Dr. Gerhard Knies pointed to the future consequences of such a crisis. “Sana'a is the capital city. It's an active place, expending and flourishing. However, using up its water resources at this rate will end its development.”

He warned that if government officials don't deal seriously with this looming disaster, it will cause mass migration of capital inhabitants due to lack of water and subsequently, Sana'a will become a deserted city. It also would be an economic loss of billions of dollars.

Increasing irrigation use by physically intervening in upgrading piped delivery systems, converting open channels to piped delivery systems, introducing pressurized irrigation and accelerating groundwater renewal through small conventional dams, sub-surface dams and other structures using rain are some possible measures of the Yemeni government, in cooperation with the Sana'a Basin Water Management Project and other international organizations.

However, many experts believe such measures are only temporary answers and not a complete solution, particularly with difficulties in controlling increasing water demands and increasing population growth rates. “Sana'a is sitting on a glass of water, but it's almost empty. One day, it'll be empty and then it will be a real disaster. Now, Sana'a is close to becoming home to two million people,” Knies noted.

“So we must organize displacement of the Sana'a population before the water is depleted or we must think about new water sources,” he added, pointing to desalination technology.

Expensive technology

The water desalination issue has been raised many times. Yemen particularly faces extreme water shortages because there is no perennial surface water in many regions. Although Yemeni authorities involved with international organizations are working to avoid this expensive technology, many experts believe desalination is an unavoidable solution to these circumstances.

The National Water Sector Strategy and Investment Program (NWSSIP) for 2005-2009 indicates the Ministry of Water and Environment's policy in this regard, as well as obstacles facing establishing such a project in Sana'a or other highland cities.

According to the NWSSIP, discourse about desalination should be limited at the present time to coastal towns or highland towns with sustainable brackish groundwater reserves that can be desalinated economically as a supplementary fresh groundwater source. The reason for this is the prohibitive cost of pumping desalinated water over long distances to high altitudes.

However, the NWSSIP referred to the importance of considering such technology. “It would be a mistake to delay introducing desalination until all groundwater resources are depleted. Citizens then could not afford the sudden large increase in the water tariff, which would be brought about by the high cost of desalinated water compared with relatively cheap groundwater,” the NWSSIP added.

Desalination often is viewed as some sort of magical solution to water scarcity in Sana'a and other cities, while others consider it expensive technology, especially when desalinated water must be transported over long distances or pumped to high elevations. In such cases, the amount of energy necessary to transport such water, rather than the desalination cost, becomes the deterring or constraining factor.