THE fabled Yangtze River, the third-longest in the world, is already dying from pollution and could be dead within five years.

The river’s plight reflects the water crisis facing the world’s most highly populated country.

China’s 1.3 billion people are already short of supplies because of prolonged drought in many regions — and much of what remains has been contaminated by industrialisation.

About 40 per cent of all waste water produced in China — some 25 billion tonnes per annum — flows into the river, but more than 80 per cent of it is untreated beforehand.

Matters have been made worse by the construction of the controversial Three Gorges Dam, which environmentalists say has changed the oxygen content of the river, as well as creating a huge rubbish dump in its reservoir.

Yuan Aiguo, a professor at the China University of Geosciences based in the Yangtze port of Wuhan, said: “Many officials think the pollution is nothing for the Yangtze, which has a large water flow and a certain capability of self-cleaning, but the pollution is very serious.”

Industrial waste and sewage, agricultural pollution and shipping discharges were to blame for the river’s declining health, the experts said.

The river, the longest in the world after the Nile and the Amazon, runs from Qinghai and Tibet in the remote far west, through 186 booming cities, before emptying into the sea at Shanghai. For the futuristic city’s 20 million residents, the death of the river could be critical. Lu Jianjian, a professor at Shanghai’s East China Normal University, said: “As the river is the only source of drinking water in Shanghai, it has been a great challenge for Shanghai to get clean water.”

It is not only Shanghai that could suffer if the water of the Yangtze becomes unuseable. Along with the Yellow River, it has been earmarked as part of China’s ambitious $60 billion (£33 billion) south-north water diversion scheme — a plan to pump 45 billion cubic metres (1.6 trillion cubic feet) of water per year from southern waterways, via canals, to the parched north by 2050.

Environmentalists fear that unless local governments and industries become serious about cutting pollution, most of the water shipped north will not be fit to drink.

Professor Lu said that contamination has reduced the number of species living in the Yangtze from 126 in the mid- 1980s, to 52 four years ago. The Yangtze dolphin may have already become the first cetacean to be made extinct by humans.

Fishermen complain that the Three Gorges Dam has blocked fish migration, leading to a catastrophic drop in catches. Officials say the change in the oxygen content of the water from the dam construction is killing fish. Large amounts of rubbish have built up in its reservoir, which will fall by about 40 metres (131ft) each summer, leaving a huge area of exposed land that experts fear will fill with pollution, and breed diseases.

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