(Xinhua)
Updated: 2008-06-01 09:02

MIANYANG, Sichuan - The diversion project to drain a  dangerous lake in China's quake-hit Sichuan was completed at 10 pm on Saturday, a water resources official said.

By 10 p.m. Saturday, about 135,500 cubic meters of mud and rocks have been removed from the Tangjiashan quake-formed lake, leaving a 475-meter-long channel up to 10 meters wide on the giant blockage, said Liu Ning, chief engineer of the Ministry of Water Resources and deputy director of the diversion project.

The evacuees, mainly members of the water and electricity section of the People's Armed Police Force, prepare to board on the helicopter at the dam site of quake-induced Tangjiashan Lake in southwest China's Sichuan Province, May 31, 2008. The first group of 15 earthquake relief workers handling the Tangjiashan quake-formed lake in China's Sichuan Province boarded a helicopter at 8:35 a.m. Saturday and were evacuated from the dam site. [Xinhua]

The quake lake was formed when the May 12 earthquake triggered landslides and blocked a river. The lake, which holds nearly 200 million cubic meters of water, threatened to burst through the loose blockage and flood millions of people downstream.

The water level of the lake, which had been rising about 1.6 meters daily, was seven meters from the lowest point of the blockage, Liu said.

He added that the plan to blow off the blockage with explosives has been abandoned, as the diversion channel has been completed on time.

The major project of a sluice - an irregular cube designed to discharge flooded water - from the Tangjiashan Lake is completed at quake-induced Tangjiashan Lake in southwest China's Sichuan Province, May 31, 2008. The first group of 15 earthquake relief workers handling the Tangjiashan quake-formed lake in China's Sichuan Province boarded a helicopter at 8:35 a.m. Saturday and were evacuated from the dam site. [Xinhua]

More than 10 tons of dynamite carried to the blockage by soldiers trekking mountains have been earlier taken back, so was surplus fuel and garbage, to avoid environmental pollution.

It is expected that the rising water will run over the blockage and continue its trip through the man-made canal. According to Liu, this may happen between June 1-5.

More than 600 armed police have been working around the clock over the last six days on the canal cut out on the blockage.

By Saturday night, more than 340 soldiers and engineers have left Tangjiashan, officials said.

The first group of 15 workers, mainly soldiers of the hydropower corps of the People's Armed Police Force, left in a helicopter at 8:35 a.m. Saturday, a Xinhua reporter at the site said.

They were taken to the Nanjiao Military Airport in Mianyang City for rest, he said.

The remaining 300 people will stay through Saturday night, and most of them would leave by Sunday noon, said Zhou Xiangjun, an armed police officer. About 20 soldiers would stay at Tangjiashan to monitor the situation, he said.

On Saturday, the soldiers left in helicopters and some left on foot.

"We prefer the airlift if weather permits. If the weather turns bad, we will walk out tomorrow morning," said Yue Xi, deputy chief of hydropower corps.

It takes 40 minutes to reach the airport in Mianyang and six to seven hours by foot. Evacuees have to cross two mountains if they choose to walk out, he said.

A total of 197,477 people were evacuated to safe ground as of 8 a.m. Saturday in line with an emergency plan, an official with the quake relief headquarters of Mianyang City said.

Tan Li, Communist Party chief of Mianyang and head of Mianyang City Quake Control and Relief Headquarters, on Friday renewed an order that 1.3 million people living downstream from Tangjiashan must be evacuated to higher grounds demarcated by the government.

At 4 p.m. Thursday, Tan issued a No. 1 order demanding that about 200,000 people living downstream from Tangjiashan in the main urban districts of Mianyang should start evacuation by 8 a.m. Saturday. The evacuation must be completed by 8 a.m. Sunday.

Two other plans require the relocation of 1.2 million people if the half of the lake volume was released, or 1.3 million if the whole landslide blockage is washed away.

On Saturday night, the downtown Mianyang city appeared deserted, with shops shuttered and several streets cordoned off. Sandbags were stacked at the doors of houses and buildings along the projected flood path to prevent watering from getting in.

Residents who have not so far evacuated were put through evacuation drills in the past week. They were informed that flood warnings will be communicated through signal shots and sirens.

The 8.0-magnitude tremor, which has claimed 68,977 lives as of Saturday, left 34 quake lakes in its aftermath, of which 28 threaten to burst.

Hu Yun, deputy director of the Sichuan provincial water resources department, said the danger at the quake lakes would be defused by June 10.