The water level of the Tangjiashan quake lake was still dropping on Wednesday, while experts warn that dangers remain.
As of 8:00 AM, the level had fallen to 714.62 meters from the highest mark of 743.1 meters and the lake was draining at a rate of 68.4 cubic meters a second, according to the quake lake relief headquarters in Mianyang.
Liu Qibao, Communist Party chief of the southwest China's Sichuan Province, declared on Tuesday the drainage of the swollen lake was "a decisive victory".
More than half of the 250-million-cubic-meter volume had been discharged and the number of people under threat had dropped from 1.3 million to less than 50,000, said Liu.
However, Water Resources Minister Chen Lei warned that dangers posed by the lake remained although the water level was likely to linger around 720 meters for some time.
"There are still some 100 million cubic meters in the lake, which is subject to the threat of aftershocks, landslides, heavy rain," he said.
"Another major test for us is coming as the flood season approaches. The best situation is to completely clear the water from the Tangjiashan lake before the flood season," Chen said.
Chen said experts with the ministry would fly to the lake area to conduct geological studies and assess the risks on Wednesday and Thursday.
"The 25,000 relocated residents of Mianyang are expected to return home in another two days as the flow continues," he said.
The Tangjiashan quake lake was formed after quake-triggered landslides from Tangjiashan Mountain blocked the Tongkou River running through Beichuan County, one of the worst-hit areas in the May 12 quake. It began to drain on Saturday morning through a manmade spillway.
The drained water flooded the quake-ravaged Beichuan County, then safely passed Mianyang on the Fujiang River on Tuesday, and arrived at Tongnan County, in Chongqing municipality, at around 5:00 AM on Wednesday.
The Mianyang government said city water networks had suspended intake from the Fujiang River since Tuesday night as the local water quality monitoring center found the water was contaminated by the lake outflow.
"The muddy outflow is accompanied with lots of flotsam. Reports from five monitoring stations on the Fujiang River shows the river has been polluted and is not potable," said an official with the center.
The water supply for about 500,000 people in Mianyang urban areas would come from underground reserves before the river water quality improved and the government would ensure 50 liters of drinking water for per person per day, according to the city government.
(Xinhua News Agency June 11, 2008)