The upper-reach Nanwan Water Dam and Shishankou Reservoir have got an average rainfall of 150 mm and 315 mm respectively on Friday, resulting a twist in the ongoing combat against the worst flooding on the Huaihe River since 1954.

The water level on the crucial Wangjiaba Hydrological Station may soon surge above the danger line as more rains have been forecast in the next few days, said Cheng Dianlong, deputy director of the Office of the Flood Control and Drought Relief Headquarters.

Thirteen sluices at Wangjiaba station were opened Tuesday to divert flood water into the Mengwa Buffer Zone home to 150,000 people to provide relief to more than 2 million flood-hit residents in Henan Province.

Nearly half a million people have been evacuated from the projected path of floodwater from the Huaihe River by Friday.

Cheng said that the Henan hydrological departments on the upper reaches have made good use of reservoirs and water dams to alleviate pressure downstream Saturday. The flux into the Nanwan Reservoir registered at 2,760 cubic meters per second, however that out of the reservoir was reduced to 200 cubic meters per second.

"The Huaihe riverbanks have been lashed by swelling water for several days. Putting up good defense will become increasingly difficult as more torrential rains are to come," he said.

The headquarters issued an emergency notice Saturday to all local governments along the Huaihe River, requiring them to surmount fatigue, remain high alert and carry forward the spirit fostered in battling the 1998 Yangtze River flooding which killed more than 3,000 people and inflicted about 100 billion yuan (about13 billion U.S. dollars) in economic losses.

The notice urged them to take all adverse situations into consideration to reinforce preventive measures, continue to put the human first and safeguard the lives and assets of the people by arranging for relocation in advance.

Along the Yangtze River, Guizhou, Hunan and Hubei provinces and Chongqing Municipality have been stricken by floodwater as heavy rainfall had lifted up the water levels of some branches.

The Pipazui and Zhengjiahe Hydrological Stations on the tributary Fuhe River have both registered their highest water levels in history.

Landslides triggered by mountain torrents killed six and caused three missing in Zhijin County of Guizhou Province, affected more than 673,000 people in Chongqing and inflicted the municipality 182 million yuan in direct economic losses.

Some 1,630 people in Jingshan County of Hubei were evacuated in emergency as the water collected in downtown areas were 0.5 to 1.5meter deep.

By Friday, a total of 403 Chinese had been killed with 105 missing and 3.17 million people have been relocated as the rainy season coupled with ferocious flood waters continues to batter central and southern China.