A severe drought in southwestern China is threatening the water supplies of one million people and crippling navigation on the depleted Yangtze River, state media reported on Monday.

A Chinese family tries to cool off on the banks of the Yangtze River, where the water level has dropped dramatically, in Chongqing in August 2006. A severe drought in southwestern China is threatening the water supplies of one million people and crippling navigation on the depleted Yangtze River.[AFP]

Authorities in Chongqing municipality have sent water trucks into the most parched areas to provide water for residents and livestock hit by weeks without rain, Xinhua news agency said.

Water levels on the Yangtze, China's longest river, have decreased rapidly and officials halted navigation near Chongqing city on Monday after a barge carrying 1,400 tons of timber became stranded for several hours, it said.

One of Chongqing's largest drinking water suppliers said the water level had fallen below most of the pipes the company uses to draw water from the river.

"If the water levels in the Yangtze and its upper tributary Jialing River continue to decline, we'll face a real crisis," Xinhua quoted a spokesman with Shapingba Waterworks as saying.

The region is still reeling from a severe drought last summer, the worst in decades, which forced tens of thousands of farmers to leave in search of work elsewhere. Chongqing municipality is home to about 30 million people.