Shanghai has raised its charges for drainage fees this month in a move to encourage local residents to save water and recycle precious moisture. The effort is designed to relieve pressure from the city's seriously dwindling water resources.

The city is capable of supplying a maximum of 10.64 million cubic meters of tap water daily, when daily consumption could be as much as 9.24 million cubic meters.

Ironically, the city faces the East China Sea, and is surrounded by some-22,000 big and small rivers, and rain seems as common as sunshine.

Many locals have gotten used to keeping the tap running while brushing their teeth or washing the dishes, never worrying about the seemingly inexhaustible water supplies or pausing to ponder the small increases in their water bills.

They doubt Shanghai is short of water since the annual per capita amount of water available in the area is far exceeding the national average of 2,220 cubic meters.

The fact is that only 20 percent of the water from rivers is drinkable, which lowers the available amount to local residents to about 1,000 cubic meters per capita - 55 percent less than the nation's average and 10 percent of the global average.

Experts have estimated the city will face a daily fresh water shortage of 2.58 million cubic meters by 2020 at its present population growth rate.

For years the city has adorned the United Nations list of cities and municipalities that will experience severe drinking-water problems this century.

Irrevocable facts

According to analyses from the Chinese Ministry of Water Resources, a serious water shortage will prevail in the country with an annual shortfall of 31.8 billion cubic meters from 2010 on.

By 2030, when the shortage peaks, the nation will be some 40-50 billion cubic meters under its water needs if measures are not taken.

Shanghai, situated at the estuary of the Yangtze River, is unlikely to suffer from severe drought. But it is now in great need of water for both drinking and industrial production, and has been so since 1997.

According to city officials, only 1 percent of the surface water can meet the national requirements for drinking water and 68.6 percent of the water is inferior to Class V.

The national standard for drinkable water is above Class II.

"The problem of water shortage is increasingly challenging the sustainable development of Shanghai as an international metropolis," said Zhang Jiayi, director of Shanghai Municipal Water Affairs Authority.

Now the city draws 80 percent of raw water from the deteriorating Huangpu River since there is not any improvement in the quality of its source - the Taihu Lake in Jiangsu Province.

The water quality of the river lingers around Class III to Class V throughout the year due to the poor water quality of Taihu Lake and local pollutants, according to Zhang Jiatuan, senior engineer of the Ministry of Water Resources.

Zhang's data show that since mid-June of this year, one-third of the water area in the upper reaches of the Huangpu River was covered by huge amounts of green hydrophytes, with the Taihu Lake remaining quite tainted.

"Water pollution is the major reason for the shortage in the city, which should arouse much more concern from the government and the public," said Gu Shenghua of the Municipal Hydrological General Station.

The city discharges nearly 5.8 million cubic meters of sewage daily, only a little bit more than 3 million cubic meters which is treated by processors before it enters the rivers and the sea, Gu said.

Much of the untreated waste is discharged directly into the Huangpu River system, which has caused the water there to worsen.

Water savings

Besides water contamination, wasteful consumption of clean water is also to blame for the water shortages since daily water consumption is 350-500 liters per capita in Shanghai while the national figure is only 150 liters.

"The sense of water thriftiness should become deeply rooted in the minds of local people and effective measures need to be pushed by the government before it is too late," said Yu Longxiang, an expert on water savings.

"The direct effect of economization of water is reducing the release of wastewater," said Yu. "Consequently, the city's burden of having to provide sewage treatment will be lessened. You can serve two purposes at the same time."

A recent survey shows that about 600,000 local residents are using flush toilets made in the early 1990s which use 13 liters of water for each flush. But the latest flush toilets cut over half the water used per flush.

The local government is planning to fix all the old toilets within three years at a cost of 40 yuan (US$4.8) each which will save an estimated 9.84 million cubic meters of water a year.

Over 8 percent of the tap water is lost due to aging water pipes that have many leaks. Government workers need to speed up replacement of these pipes.

The water used for cleaning the city's 1.3 million automobiles is an amazing 15 million cubic meters yearly. Of the city's 370 legally-recognized car-cleaning shops, only 30 have water-saving equipment, let alone the numerous roadside car washers.

Countermeasures

Vowing to make the city have a blue sky, green land and clean water, city leaders have been taking great efforts, especially to tackle the water problem.

Since 1998, priority has been given to treating the filthy water in rivers and creeks, with more than 1.4 billion yuan (US$169 million) invested in the cleanup process.

And efforts are paying off a little, with an obvious case being Suzhou Creek, where the previous foul odor isn't prevalent any longer.

Due to the geographic reasons, every year from December to April when the dry season comes, sea water is likely to flow into the rivers, which greatly affects water quality, according to Liang Hong with the local water authority.

The city thus has been requiring factories which draw water from underground to return twice the amount of treated water to underground aquifers to sustain the water levels and to prevent encroaching of sea water.

On the recent inspection tour to Shanghai, 19 members of the Chinese Academy of Sciences and Chinese Academy of Engineering, including 81-year-old Qian Zhengying, suggested the city promote water-saving devices while tapping new water sources and reducing water pollution to the greatest extent feasible.

Qian Zhengying proposed shifting water intakes from the Huangpu to the Yangtze, which has better-quality water.

In addition, related institutions must pay enough attention to preventing salt water from intruding into the Yangtze's mouth, Qian warned.

"Shifting the water intake sources from the deteriorating Huangpu River to the Yangtze River is a must for the city," said Wang Songnian, a senior water expert and top official of the local water authority.

"The problem is how to exploit the Yangtze River," he said.

The Ministry of Water Resources has been conducting a feasibility study to consider constructing a reservoir at some site on the mouth of the river, yet the complicated geographic and hydraulic situation has been hindering the effort.

Affordability is also a factor affecting the decision. Compared with developed countries, Shanghai is doing very well in water making and sewage treatment on the present economic basis, he added.

(China Daily August 17, 2004)