Water began flooding the town after the nearby Xingshan Reservoir and the Wende and Songhua rivers overflowed. Rescuers were delivering supplies by boat and moving people to higher ground.

In Jilin city in Jilin province, workers were busy recovering thousands of barrels of chemicals that had tumbled into the Songhua River after a flood swept through a local factory.

Reservoirs filling up

Al Jazeera's Melissa Chan, reporting from Beijing, said more than a thousand people are killed annually in China floods but that the current situation was worrisome because of unusually heavy rains.

"The worry this year has been on the dams and the reservoirs ... This year it's been so much extra rainfall, about 15 per cent more than usual. 

"That complicates the situation because the reservoirs are getting full and the dams are nearing their maximum capacity."

Flooding has hit areas all over China. A total of 875,000 homes have collapsed and almost 10 million people have been evacuated, according to Xinhua.

The Three Gorges Dam, the world's largest hydroelectric project, has reached 90 per cent of its full capacity.

Thousands of workers have sandbagged riverbanks and checked reservoirs in preparation for potential floods expected to flow from the swollen Yangtze and Han rivers, an official with the Yangtze Water Resources Commission, said.

"Right now, the Han river in Hubei province is on the verge breaching warning levels," the official, who gave his name as Zhang, said.

The Han is expected to rise this week to its highest level in two decades.

Workers were prepared to blast holes in the river's embankment to divert flood waters into a low-lying area of farms and fish ponds, Xinhua said.