After two days of non-stop digging, the drainage sluice for the barrier lake at Tangjiashan is now 50 meters long, only a quarter of its planned length. Vice prime minister Hui Liangyu is there to guide the rescue work.

Over the top of this mountain is the Tangjiashan barrier lake.

Excavators are working there day and night to dig a 200 meter long sluice to divert the water.

Vice premier Hui Liangyu stresses the rescue work relies on the cooperation of people, the army and experts. He also encouraged the rescue team and expressed his great confidence in their ability to defuse the danger of flooding.

Experts have intensified their monitoring of the barrier lake, as the water level rose 1.79 meters on Tuesday.

Minister of Water Resources Chen Lei said, "The best way is to open an aqueduct to lower the water level. Otherwise there will be more water stored in the quake lake. It will no doubt increase the danger to people who are downstream of the river. We are now racing against time."

Engineers are considering using explosives to drain the lake before it bursts.

Liu Ning, Chief engineer of Ministry of Water Resources, said, "As the second batch of equipment arrives, the project will enter the second phase. We have to first clear these woods that stand in the way."

On Tuesday evening, rescuers blasted several tree trunks mixed in the blockage. At least 20,000 cubic meters of debris had been removed the same day.

The sluice is expected to be ready in about three to five days, and at least 50,000 cubic meters of debris need to be removed to build the diversion channel. But local authorities aren't taking any chances as evacuation has already started.

Lin Xin, vice mayor of Mianyang City, Sichuan, said, "The Tangjiashan barrier lake could burst in three possible ways. If a third of the lake bursts, nearly 158,000 residents in Mianyang would be evacuated. If half of the lake bursts, about 1.2 million residents would be evacuated. If the whole lake bursts, 1.299 million would be evacuated."

So far, more than 100,000 people in and around Mianyang City have been relocated.

(CCTV May 28, 2008)