The waters of the Yangtze have fallen to their lowest levels since 1866, disrupting drinking supplies, stranding ships and posing a threat to some of the world’s most endangered species.

Asia’s longest river is losing volume as a result of a prolonged dry spell, the state media warned on Wednesday, predicting hefty economic losses and a possible plague of rats on nearby farmland.

News of the drought - which is likely to worsen pollution in the river - comes amid dire reports about the effect of rapid economic growth on China’s environment. But the immediate concern is the Yangtze, which supplies water to hundreds of millions of people and thousands of factories in a delta that accounts for more than 40 per cent of China’s economic output. The Chinese media report that precipitation and water levels are at or near record lows in its middle and upper stretches.

The scale of the problem was revealed by the Yangtze Water Resources Commission in a report on the Xinhua news agency’s website.

It said that the Hankou hydrological centre near Wuhan city found the river’s depth had fallen to its lowest level in 142 years.

The measurement confirmed fears raised in recent weeks by the appearance of islands and mudflats not normally seen at this time of year. Local farmers reported far more ships than usual being trapped in unnavigable shallow waters.Jianli county is among the areas suffering water shortages. Officials say the problem has grown worse in the past 10 years, raising concerns of a link to climate change.

“Before 1996, we were short of water for three months of the year, but now there are only three months when we can use water as normal,” Wu Chunping, the vice-manager of Jianli county’s water utility, said.

Among the endangered animals likely to be affected are the finless porpoise and the Chinese sturgeon, which returns to the sea at this time of year.

With the Yangtze three times as crowded with traffic as the Mississippi, conservationists fear the animals will be torn up by boat propellers or contaminated by more concentrated pollution from the 9000 chemical plants along the Yangtze.