Water overflows from a lake formed after landslides blocked a river in Qingchuan county, Sichuan, yesterday. The natural overflow eased the threat of flooding.

Twenty-one lakes have formed after landslides blocked rivers in Sichuan, but they "do not pose a serious danger at the moment", the vice-governor of the province said yesterday.

Expert teams have reached all the lakes to monitor the situation, Li Chengyun told a media briefing, adding that various water projects in the province are basically safe.

At least two water conservancy specialists, accompanied by at least 10 People's Liberation Army personnel, are monitoring each of the lakes.

"Preliminary monitoring stations have been set up near each lake," he said.

His remarks came after thousands of people were evacuated from Beichuan county from Friday as a precaution.

The government will evacuate people in the downstream areas of the lakes as soon as situation warrants, Li said.

Massive landslides following the magnitude-8 earthquake on May 12 have dammed rivers and lakes in several counties, posing a threat to downstream areas.

Twenty-one landslide blockages have been reported in Beichuan and Anxian counties in the city of Mianyang, Qingchuan county of Guangyuan, Mianzhu and Shifang cities of Deyang, and Pengzhou city near the provincial capital Chengdu.

Water overflowed three of the blockages in Qingchuan county yesterday morning but posed no danger, the local relief headquarters said.

The three lakes had more than 10 million cu m of water, said an official with the headquarters for quake relief in Qingchuan.

More than 20 million cu m of rocks slid into rivers after the quake and formed the lakes.

Nearly 60,000 people live in seven towns and a county seat in the lower reaches of the three lakes.

The county has decided to allow natural overflowing and artificially divert water to ensure safety.

The most dangerous build-up of water, about 3.2 km upstream from Beichuan county, measured 9 km long, 200 to 250 m wide and 40 m at the deepest sections.

With an estimated volume of 30 million to 40 million cu m, it is a major threat to the Beichuan county seat and its downstream areas, the Sichuan provincial water conservancy bureau said.

Seven more landslide blockages were found in Beichuan county, about 160 km from the epicenter, Wenchuan.

The earthquake and the aftershocks also damaged some water storage facilities in Sichuan Province, though no burst reservoirs were reported.

(Xinhua News Agency, China Daily May 19, 2008)