Rainstorm-triggered floods in southwest China's Chongqing municipality have killed at least 10 people in the past four days, officials with the Ministry of Civil Affairs said Wednesday. Another person is still missing.

Continuous rainfall since Sunday also caused landslides and mud flows in some parts of the mountainous municipality.

More than 1.5 million Chongqing residents have been affected by the floods, and 123,000 have been relocated, ministry official said.

A car runs throught the flooded street in southwest China's Chongqing Tuesday August 4, 2009. [Xinhua]

Direct economic losses amounted to 680 million yuan ($100 million), with more than 10,000 houses toppled in the floods and 16,000 more damaged.

The government yesterday issued an alert and urged stepped-up efforts to fight against the flooding in the upper and middle reaches of the Yangtze River, expected to be the worst since August 2004.

Flooding has been caused by continuous heavy rainfalls in the region.

Maximum inflow into the Three Gorges Dam would be 56,000 cu m a second, the Office of State Flood Control and Drought Relief Headquarters (SFDH) warned.

The Three Gorges Dam is capable of reducing flood waters by between 27,000 and 33,000 cubic meters a second.

The SFDH ordered the Danjiangkou Dam, located at the junction of two main tributaries of the Yangtze River, Hanjiang River and Danjiang River, to open one of its sluices Wednesday for the first time this year to ease flooding.

Meanwhile, China's third largest freshwater lake may burst its banks and flood wealthy residents in Taihu Lake basin.

Contingency plans were being set up last night as continued rain pushed water levels upwards and tropical storm Morakot headed towards the country's eastern coastline.

The cities of Suzhou, Wuxi, Changzhou and Huzhou surround the 2,400-sq-km lake, which is a major drinking water source in Jiangsu province.

After persistent rainfall since July 21, the water level yesterday reached 3.84 meters, 0.34 meters higher than the warning level, according to the Taihu Lake Basin Management Bureau under the Ministry of Water Resources.

"The growth of the water level has slowed, but the lake's ability to drain is limited. Meanwhile, the upcoming tropical storm could increase the destructive power and make flood conditions unpredictable," Xu Hong, deputy director of the bureau's flood control and drought relief office said yesterday.

"Morakot will be much more likely to come directly through the Taihu Lake basin. If so, the flood control work will be more challenging," Xu said.

The year's eighth tropical storm, Morakot - which means "turquoise" in Thai - is moving toward Zhejiang and Fujian provinces at 10 km per hour and is growing stronger.

The country's meteorological administration said Morakot will likely be upgraded to a typhoon by the time it hits China on Saturday.

While improving the draining ability of Taihu Lake, the bureau also sent two teams to advise flood control departments in Jiangsu and Zhejiang provinces to prepare for the approaching storms.

"They will be on 24-hour standby, and keep close watch on the changing weather and the water level," Xu said.

In addition, local authorities were asked to prepare emergency shelter and relief materials while increasing checks on the construction sites, infrastructure and other buildings that could be vulnerable to flooding.

In South China's Guangdong province, Goni, the seventh typhoon this year, lashed Haiyan township of Taishan at 6:20 am yesterday, with winds of up to 82 km per hour.

It brought heavy rains to the Pearl River Delta region, with a rainfall of 186 mm being recorded in the city of Zhuhai.