China 'quake lake' still dangerous despite drainage

China claimed initial success Sunday in draining a swollen "quake lake" in the country's south-west, but water levels kept rising and senior officials warned the situation remained dangerous.
Soldiers had already dug one drainage channel to contain Tangjiashan lake, and were working Sunday to clear a second one in hopes of reducing the risk that it might burst through its banks, state-run Xinhua news agency reported.
"Generally speaking, construction of the lake's drainage projects is proceeding well, but the lake remains dangerous for hundreds of thousands of people downstream," said General Ge Zhenfeng, Deputy Chief of the General Staff of the People's Liberation Army (PLA).
"It will take us a few days to eliminate the potential danger of the lake," Xinhua quoted the general, who is supervising the relief work at the site, as saying.
The lake has become one of the most pressing issues in the aftermath of the May 12 quake that struck mountainous Sichuan province, killing 69,136 and leaving 17,686 others missing, according to the latest toll issued Sunday.
Millions more have been left homeless by the 8.0-magnitude quake, which triggered massive landslides that blocked rivers and created more than 30 unstable "quake lakes," including the Tangjiashan one on the Jianjiang river. Troops on Saturday began draining water from the Tangjiashan lake through a hastily dug channel to stop it from breaking through its banks and emptying 220 million cubic metres (7.8 billion cubic feet) of water downstream.
Between 400 and 500 millimetres (16 and 20 inches) of rainfall, well above the normal level, was forecast upstream in June and July, Xinhua reported, citing Water Resources Minister Chen Lei.
"This poses a challenge for the already swollen lake... Aftershocks, landslides and leakage are also threatening the lake's barrier," Chen said during a visit to Sichuan, according to Xinhua.
Landslides could take place on mountains not far from the lake, causing another 17 million cubic metres of rocks and earth to crash into the water, Xinhua said.
The lake would immediately burst its banks if that happened, sweeping away workers on its barriers, according to the agency. Soldiers aided by 30 bulldozers and excavators were still working on the channels, Xinhua said.