Parts of urban streets and lanes in south China cities hit by tropical storm Bilis are still inundated in water, days after the storm disappeared.

Many cities in Hunan, Fujian, Guangdong, Zhejiang, Jiangxi provinces and Guangxi Zhuang Autonomous Region are suffering from flooding due to ineffective urban drainage, say local government departments.

Some streets and lanes in Nanning, capital of Guangxi, are still water courses. In the city of 2.49 million, many sections of the drainage system date back to the 1960s. Outfalls are often blocked by plastic bags full of construction waste.

Cheng Xiaotao, senior engineer with the China Water Conservancy and Hydroelectric Power Research Institute, said only 177 of 642 cities at risk of serious flooding had their urban infrastructure built to meet the national flood-control criteria, which came into effect in 1995.

In Guangxi, more than 6.53 million people were affected by the Bilis-induced rainstorms, flooding and mudslides, which incurred over 2.2 billion yuan (US$2.75 million) in losses.

The damage in Nanning was unlikely to be repaired quickly because work was hindered by waterlogging.

"The disappearance of natural water storage plains and low-lying ground in the city, as a result of urban development, is to blame for the serious waterlogging in the urban area," said Cheng.

As China's urban population continues to grow from the present 460 million to an estimated 800 million in the middle of this century, cities would be under growing threat of flooding in heavy rain.

(Xinhua News Agency July 21, 2006)