Water drained from the Tangjiashan "quake lake" flows down a landside site in quake-devastated Mianyang City, Southwest China's Sichuan Province, June 7, 2008.

　　MIANYANG, Sichuan Province, June 7 (Xinhua) -- Engineering soldiers began to use dynamite to blast off boulders and objects in the dangerous Tangjiashan "quake lake" so that water drained faster through a man-made sluice channel.

　　The lake started to drain on Saturday morning and water flowed at a speed of nearly 10 cubic meters per second at 7 p.m., far more than the previous two cubic meters per second.

　　More than 100 soldiers, with the help of more than 20 excavators, were still widening and deepening the sluice channel and digging another on Saturday evening.

　　Minister of Water Resources Chen Lei told Xinhua that the lake was still dangerous despite the drainage.

　　Rao Xiping, head of the Beichuan hydrometeorological station, said the water level of the lake was still rising due to the slowness of the water flow.

　　
Picture taken on June 7, 2008, shows water flowing down through the man-made sluice channel from the Tangjiashan "quake lake" in Mianyang of southwest China's Sichuan Province. Experts calculated that the water stream flows at a speed of seven to eight cubic meters per second after a boulder in the channel is blasted on Saturday afternoon accelerating the speed from previous two cubic meters per second.

　　The water level in the lake stood at 740.97 meters above the sea level at 5 p.m., 0.6 meter higher than the time when the quake lake started to overflow.

　　The quake lake was enlarged by 13.5 million cubic meters, and has reached 229.5 million in total, according to experts at the Tangjiashan quake lake relief center.

　　The experts also said no strong rainfall is expected until June 16, which will be good for the quake relief work. The possibility of a strong aftershock measuring 6.0 or above on the Richter scale is also slim, they said.

　　The swollen lake was formed by a massive landslide following the May 12 earthquake that jolted the country's southwest. It is posing a major threat to 1.3 million people downstream.

　　Some 600 armed police and soldiers worked for six days and nights to dig a 475-meter channel to divert water from the lake.

　　More than 250,000 people in low-lying areas in Mianyang have been relocated under a plan based on the assumption that a third of the lake volume breached its banks.

　　Two other plans require the relocation of 1.2 million people if half the lake volume is released or 1.3 million if the barrier is fully opened.

　　The lake is also posing a threat to the Fujiang river bridge on the Baoji-Chengdu Railway, a critical part of the railway network in western China.

　　Liu Yongzhan, a pontoon bridge army colonel, told Xinhua that his men are ready to protect the bridge by intercepting, bombarding and salvaging large floaters that may be washed down by the flooding.

　　The swollen quake lake has also put China's longest oil pipeline at risk. The pipeline, winding from Lanzhou via Chengdu to Chongqing, was 60 kilometers downstream from the lake.

　　Liu Xiaozhong, director in charge of the pipeline protection work, said that the pipeline will not be disrupted according to the work plan on the quake lake.

　　More than 100 Petro China staffers and 20 pieces of large equipment were assembled for protecting the pipeline.

　　With a capacity of transferring 6 million tonnes of oil each year, the pipeline provides 70 percent of product oil to Sichuan and neighboring Chongqing Municipality.

　　If the line was cut, refined oil in storage could only supply Sichuan for three days, whereas repair work would take 30 days.

Some machines are submerged by the water drained from the Tangjiashan "quake lake" in the quake-devastated Mianyang City, Southwest China's Sichuan Province, June 7, 2008.

PLA officers work near the sluice channel of the Tangjiashan "quake lake" in the quake-devastated Mianyang City, June 7, 2008.

PLA officers check a map of quake-devastated Mianyang City, June 7, 2008.

Water drained from the Tangjiashan "quake lake" flows in the quake-devastated Mianyang City, June 7, 2008.