Given the unqualified optimism about the future of Suzhou Creek, environment experts prescribe a heavy dose of caution, according to China Daily.

Three years ago, real-estate agents selling apartments along the infamous Suzhou Creek still needed to show water samples to clients to prove the upgrading of water quality in the creek.

Those days are now past and the improvement in the water quality in the creek can literally be seen.

The concept of "Riverside Residence" is starting to have real meaning in Shanghai life.

"Brilliant City", one of the best-known apartment buildings erected near Suzhou Creek in recent years, already has 99 per cent occupancy, ranking it top of all the city's newly finished buildings.

Also in the past three years, the houses have managed to double their original 3,000 yuan (US$361) per square metre price.

Today, the real estate business along Suzhou Creek is thriving thanks to the government's commitment to stick to its decision of cleaning up the creek.

Statistics show that prices for houses along the waterway are 10 to 15 per cent higher than for housing only a little way away from the creek.

"Such a situation was really unforeseeable years ago when people struggled to avoid settling down near the smelly waterway," Huang Lu, a salesman for the "Brilliant City" project, said.

As the market reflects, local residents are confident about the future of the creek.

Fang Fengzheng, an 82-year-old woman, who has lived near the creek from the day she was born, has experienced the whole process of the once clean creek turning dirty, and the dirty creek becoming more and more clean.

Recalling the bad old days, Fang couldn't help frowning.

"The water was smelly," she said. "If it was only black and dirty we could still bear it by not looking at it but the terrible smell was something you couldn't ignore. And it was just impossible to shut the door and windows all the time."

Today, the position is totally different. "The smell has vanished and the fish have returned," Fang said, crediting the municipal government for the achievement.

"If the current good work continues, the creek could soon return its former crystal-clear state just as I saw when I was a small child. All my old neighbours believe in that."

Yet, is the future really as bright as Feng and her old neighbours expect?

As experts point out, a whole century of pollution can't be so easily overturned.

"It is almost impossible for the creek to go back to its crystal clear state," said Zhang Mingxu, a professor at Shanghai Environmental Sciences Academy.

His words are disappointing but contain some truth.

Take a look at the Thames in London. So much effort has been made and so many years have passed but the water is still yellowish in colour.

"The media have given too much exposure to temporary achievements, boosting the expectation of the locals and putting a lot more pressure on us," said Hong Hao, director of Shanghai Environment Protection Bureau.

"It is not that easy to clean up the river which we have been polluting for so many years."

The city has already invested 8.65 billion yuan (US$1.04 billion) for the first phase of the 12-year rehabilitation project from 1998-2010.

One of the most important tasks involved in the project is to stop the pollution at its sources, by re-arranging pipes that empty pollutants into the creek to treatment stations. The treated waste is then discharged into the Yangtze River which, because of its size, has a better self-cleaning capability.

So far the city has successfully blocked 80 per cent of the 3,000 pollution sources along the six most polluted tributaries of the creek.

But to block all the pollution sources can be very difficult.

"The sub-standard pipelines from those old buildings make blocking them off an impossible task for some years," Zhang said.

Many houses in Shanghai still use the same pipes to discharge both stormwater and sewage.

The system copes well on dry days as the pumping stations can send the sewage to the treatment stations. But when it rains, the pumping stations' pipes are not large enough to handle all the waste and most is simply discharged directly into the creek.

Although the clean-up has included the rebuilding and enlargement of the pumping stations as part of the second-phase of the project, to eliminate the problem entirely requires the reconstruction of many old residential buildings which is just too big a task at the moment.

"In the suburbs, some farmhouses may still be discharging their waste into the waterway," Zhang said.

"So blocking off all the pollution sources is not an isolated project. It involves the city's overall development and needs a longer time span, much longer than 10 years."

Water tests show that the upper reaches of Suzhou Creek in Jiangsu Province are also deteriorating, adding to the difficulties of the clean-up.

To speed up the cleansing process, other methods such as cleaning the sediment in the creek and pumping oxygen into the water are also being used.

The sediment, rich in heavy metal elements and organic substances, takes in dissolved oxygen and discharges smelly waste such as methane and sulphide into the water. Only by removing it, can the water stop yielding smell and clean up.

Sluice gates are used in the project to force the less polluted Huangpu River water to run into the creek and flush away the dirty water.

"Of course, the water of Huangpu River is also not satisfactory, but we can't find better rivers in Shanghai," Zhang said.

Even after using so many advanced methods, and after such a huge investment, what Shanghai can expect at the end of the 12-year project is most probably "Standard V" water, the lowest quality for scenic rivers, according to an official from the Suzhou Creek Rehabilitation Project Head Office.

(China Daily November 4, 2002)