Besides building reservoirs and diverting water from the humid south to water-hungry north, thirsty China has finally decided to appeal to the sea for freshwater as the water shortage crisis worsens in the world's most populous nation.

The National Development and Reform Commission, China's top planner and financier, will soon finish a special planning program this year with the State Oceanic Administration to freshen seawater for its drought-hit northern and coastal areas.

Officials and scientists say the program spells China's strategic choice in the new century to tap new fresh water sources via seawater desalination to settle the country's water resources crisis.

"Freshening seawater and salt water has become a strategic guarantee for China to resolve its water crisis," said Gao Congjie, an academician of the Chinese Academy of Sciences.

"Seawater freshening is a necessary, feasible, and inevitable choice in China," Gao told an international seminar on seawater desalination and utilization held in north China's Tianjin Municipality.

According to the seawater freshening program, China will upgrade its capability to desalinate 100,000 to 150,000 tons of seawater each day in 2005 to satisfy the daily demands for about 7. 5 million people.

The daily amount of desalinated seawater will then increase to 300,000 to 400,000 tons to meet the consumption of more than 20 million Chinese by 2010, compared to China's current 40,000 tons of desalinated seawater.

Abdulhamid Al Mansour, president of the International Desalination Association (IDA), said that desalinated seawater has become an important part of world fresh water production and it is an inexorable trend for the popularization of and development of desalinated water to solve world water resources problem.

Mansour said seawater desalination was of great importance to developing countries like China too as more than 100 million people worldwide are now relying on desalinated seawater for drinking water.

With a population of about 1.3 billion, China, though ranking only after Brazil, Russia and Canada in fresh water resources, has become one of the 13 countries with the most serious water shortage problem in terms of per capita water resource possession, especially in its arid northern and northwest regions.

Currently, over 400 out of 600-odd Chinese cities are short of water, with Beijing and Tianjin, the national capital and a major port city in the north, at a critical moment of water shortage, according to statistics from the Ministry of Water Resources.

Meanwhile, rural people in some arid areas, as well as those people living in many coastal cities, also have to endure acute water shortages, either for farming or drinking.

China will be short of 40 billion cubic meters of fresh water this year and reach its extreme limit of water consumption by 2030, according to a report on the country's sustained development of water resources by the Chinese Academy of Engineering.

The changes are too sharp to believe in the country where about 20 years ago water was virtually free of charge and claimed a low price in the 15 years after 1985.

To curb water shortage, many large projects including the 59-billion-dollar gigantic water diversion project to channel water from the country's water-rich south to the dry northern part are now under construction in China.

Chinese State leaders include water shortages in their speeches on the nation's development strategy while slogans advocating water conservation seem to have become a fixture at public taps.

Chinese President Hu Jintao and Premier Wen Jiabao both recently underscored the importance of fostering a water-saving society.

Wang Shucheng, minister of Water Resources, acknowledged that water shortage and pollution have become a bottleneck impairing China's sustainable development, saying the problem was one of the tough challenges China has to deal with in the next two decades, a pivotal period for the country's further construction of a well-off society.

Though raising water prices to curb waste is on the government's agenda, Wang Shichang, a seawater desalination researcher in Tianjin University, said desalinating seawater in coastal areas and bitter water in arid northwest regions is also a good choice due to lower costs.

The cost to freshen seawater in China has dropped in recent years as major desalination equipment is now 50 per cent cheaper than about 10 years ago. The price of desalinated water is comparable to tap water and water for industrial use.

"The current seawater desalination technologies have explored a new stable and lasting way to supply water for China and the world, " said Wang. "Freshening sea water has become inevitable."

"Desalinated seawater can become the second major source of water supply in Chinese coastal cities in the short run," Wang said. "In the long run, desalinated seawater can ease or even ultimately solve the water crisis in northern China."

China has currently 10 seawater desalination plants in coastal cities and more are to be built in Shandong, Tianjin, Zhejiang with a daily capacity of 100,000 to 200,000 tons each.

Scientists suggest the seawater desalination technologies can also be applied in drought-hit western China to freshen salted water there. Meanwhile the IDA had promised to build a long-term information exchange mechanism with China while planning its branch in the country.

"Seawater desalination technologies have become important means for China to tackle its water crisis," said Academician Gao Congjie.

(China Daily April 24, 2004)