Dirty, stinking, with plastic bags and dead animals floating on the surface of the water - few would not hold their breath and turn their heads when walking past Suzhou Creek.

While Shanghai people talked proudly of their city's mushrooming skyscrapers and exotic night scenes, they were embarassed to talk about Suzhou Creek. When Shanghai dreams of turning itself into a city like Paris, London or New York, thoughts of the heavily-polluted river make the dream less enticing.

It's clear that a beautiful river can add to the glory and beauty of a city, but few would deny that a dirty black river significantly detracts from the image of a city. Suzhou Creek has had that effect on Shanghai.

This 5,000-year-old waterway has nurtured Shanghai from its days as a small town.

It's 54 kilometres used to be most important water course and source of drinking water.

But everything changed as the city grew into a giant, with increasing population and pollution. Since the 1920s, more and more industries poured their untreated waste into the creek and, as the city's population grew further, ever more people used it as a place to dump trash and sewage.

"The same rising industry that made the city prosper resulted in the death of the river," said Wang Hu, an expert from the Shanghai Academy of Social Sciences.

By the mid-1980s, Suzhou Creek ranked as one of the world's most heavily polluted bodies of water.

By the late 1990s the pretty dragon had become a stinking monster. Those living close to the river had to keep their windows closed day and night to avoid the strong smell from the water.

They only opened their windows to throw bags of rubbish or dead animals into the river.

"No one even wanted to throw themselves into the river to commit suicide," said Zhang Yan, a 40-year-old worker who collected the rubbish from the water. "I saw a lot of people who intended to jump into the water but were so disgusted they changed their minds. Maybe the revolting smell and colour of the water drove them away."

The deteriorating situation of the river wounded the city. The government at last decided to take action at the end of the 1990s, long after fish had completely disappeared from the creek.

"I cannot shut my eyes when I die unless fish have returned and the water has become clean," said Xu Kuangdi, the former mayor of Shanghai.

The year 1999 saw a turning point for Suzhou Creek when the first phase of a programme costing 8.65 billion yuan

(US$1.04 billion) started to rehabilitate Suzhou Creek.

The government reduced sewage discharges into the river and water locks were built between the creek and its neighbouring Huangpu River. Oxygen began to return to the dead river.

The first phase of the rehabilitation plan ended in 2003, by which time the smell and colour of the water had significantly improved.

Green spaces were built to beautify the landscape along the creek in the downtown area.

The second phase, aiming to improve the water quality, started in 2003 and is scheduled to end this year. A total of 4 billion yuan (US$480 million) has been invested in the project with the support of Asian Development Bank.

A 25,000-square-metre water reservoir has been completed to collect rain water, which will be treated before pouring into the creek.

The waste water from 320 out of 636 factories along the Suzhou Creek and its branches also will be thoroughly treated by the end of 2005.

"The water quality has been improved a lot," said Cao Lulin, vice-director of the Shanghai Environmental Science Research Centre. "We have confidence in Songjiang bass. These fish used to live in Suzhou Creek and will return in the following 30 years."

At dawn groups of people can be seen exercising near the creek these days. Others sing Peking opera under the trees along the river.

Not far behind them, apartment buildings and exotic houses mushroom with construction cranes still at work. Real estate has boomed along with the improvement of the creek's water quality.

The rehabitation of the creek will end in 2010, by which time it should be a "silver belt" for the city.

"The government is planning to dig out the silt from the bottom of the river," said Cao. "That will be a major project which will change the ecological system in the river."

"The silt on the bottom of the river plays a major part in damaging the water quality," said an official from the Shanghai municipal government, "Dealing with it will be the main task in the coming years."

Another problem is the disposal of the silt, said Cao.

A team from Tongji University has researched the possibility of converting the silt into construction materials and chinaware. The proposal was challenged by experts from the Shanghai Environmental Science Centre, who claimed the silt contained too many hazardous materials.

What Suzhou Creek waits for now is the return of Songjiang bass, a fish that thrived in the water over most of the last 5,000 years.

"Signs of Songjiang bass in the river will show we have succeeded in dealing with the Suzhou Creek," said Cao.