Lakes formed by landslides still on verge of bursting
Several lakes formed by earthquake-induced landslides in Qingchuan county are still on the verge of bursting, threatening the lives of thousands of people living in the nearby mountains and lowlands as well as those downstream.
Water resources and dam experts said on Saturday there was no immediate danger of the lakes being breached because the natural dam walls were very thick and water levels were unlikely to put enough pressure on them.
The conclusion followed a mass evacuation of Beichuan , where thousands of people were urgently forced to leave the area or climb to higher ground in case a lake broke its banks. But Su Peicheng, former Qingchuan water resources director and now deputy chairman of Qingchuan's Chinese People's Political Consultative Conference, said at a disaster relief centre in Guanzhuang township that the earlier estimation was heavily qualified.
'We have to have continued clear weather and no major aftershocks to keep those lakes from breaching. Heavy rainfall or strong aftershocks could trigger a burst at anytime,' Mr Su said.
At least 10 lakes were formed upstream of the Qingzhu River when landslides sent huge amounts of rocks into the waterway, forming natural reservoirs. The three biggest in Hongguang held about 20 million cubic metres of water, equivalent in capacity to a medium-sized reservoir.
'In my estimation, water levels downstream should rise at least 4 to 5 metres if those lakes burst,' Mr Su said. If a flood did happen, it would roar through two other counties and one district in the city of Guangyuan before joining the Jialing River, affecting the lives of up to 300,000 people on its way.
'It could be a nightmare ... I have to say the threat is real now,' Mr Su said.
Earlier reports said thousands of People's Liberation Army soldiers had been sent to the lakes to prevent such a disaster but Mr Su and a senior PLA officer confirmed that no one was doing anything about the lakes except monitoring them.
Water engineering experts had suggested carving away part of the top of the dam walls to allow water to seep out more quickly, an idea described by the officer as 'flatly unrealistic'.
'Most of their opinions are based purely on theory and are not practical at all for this area. They should tell me clearly how our soldiers can stand on the loose dams and dig channels under their feet,' he said.
Mr Su said 24 men had been sent to the mountains close to the dams to monitor the situation but no other action had been taken.
'We're relying pretty much on nature to solve the problem.'
It is hoped the water will run downstream through the porous dams without causing a total collapse and, that over the longer term, water levels will fall without causing further damage.
But rainfall and aftershocks could change everything. More rain would put more pressure on the dams and aftershocks could knock the debris lose, unleashing potentially deadly forces. Disaster relief officials have started preparing for the worst. The PLA official said his soldiers had talked to civilian authorities about an evacuation.
County and village officials told residents about the plans and some evacuation routes have been clearly marked in populous areas.
But there was confusion about how long it would be between the arrival of the flood and the firing of three flares to warn people that this had happened.
'They said a flood could arrive 20 to 30 minutes after the warning signals and messages, and I think we could easily retreat to higher ground within this time span,' Hongguang party secretary Cheng Dong said.
About 1,100 people from Hongguang have relocated to Guanzhuang since the quake destroyed their communities. But there are also hundreds of villagers opting to stay in their remote homes.
'I am not afraid of a flood, but I want to take some food home as my child and parents have been hungry for days,' said Zhao Chengping , who trekked through about 10km of mountain trails to make it to Guanzhuang's food distribution centre.
Food, water and rescuers have yet to make it to his village and many villagers travelling long distances for food shared his sentiments.
Zhang Ping , 32, was sobbing in front of the makeshift temporary disaster relief office after hearing there was no food, not even for her hungry four-year-old son. 'I came days ago and they told me there was no food and to come back two days later. Now I'm back, they still say there's no food,' Ms Zhang said.
Villager Li Siming shouted in front of the tent, accusing village party officials of fleeing his community, leaving it in chaos. He said he just wanted food and water, not meaningless information about flood dangers.
