Floodwaters in a barrier lake formed after Sunday's earthquake in Yunnan province will be discharged within two days after an explosion is set off in the debris barrier, a police official in charge of the explosion said on Thursday.
"We have carved out a simple road leading to the barrage and the collapsed part of the mountains on the sides, allowing our machines to go in," said Liu Ge, from the water and electricity section of the Chinese People's Armed Police Force. Liu is responsible for carrying out the explosion at the barrier lake.
Preparations are underway so the explosion can be carried out on Friday or Saturday.
The plan for removing the barrier lake has been approved, and a flood relief channel, measuring 5 meters wide and 8 meters deep, will be excavated on the top of the barrier.
The digging of the channel is expected to take about five days on the condition that more than 150 machines, including excavators, bulldozers and loaders, work day and night.
"The risks of the barrier lake are under control," Sun Huaikun, a senior engineer dealing with the barrier lake, said on Thursday. "But the response plan should be implemented as soon as possible."
The part of the Niulanjiang River that runs through Ludian county, the epicenter of Sunday's quake, was blocked by rocks and mud from mountains on both sides of the river.
Based on the current inflow, it is estimated that the water level could reach around 1,176 meters by 11 am on Friday, nearing the height of the barrage (1,216 meters), according to the water authority in neighbouring Huize county.
If the water overflows the debris barrier, it might affect more than 2,000 people and 5,500 houses. Roads and two power stations that are downstream also could be damaged.
More than 4,200 people living downstream have been relocated to avoid the flooding.
To discharge the water in the rising barrier lake, the top priority is to control the inflow of water, Sun said.
The reservoir upstream from the barrier lake has stopped discharging water since the earthquake.
A local resident surnamed Li said he was worried about the rising barrier lake, because it has submerged part of the village where he lives.
"We cannot go back home unless the flood recedes and the roads appear again," he said.