The lake, at Tangjiashan, is currently holding 130Mm3 of water, according to Liu Ning, Ministry of Water Resources chief engineer, who is overseeing diversion work. The water level was 727.09m yesterday, only 24.21m below the lowest part of the barrier.

River diversion work is currently underway. As of noon on Tuesday, 26 sets of machines, five tons of fuel and 157 workers had been airlifted to the lakeside while about 1200 soldiers arrived on foot carrying ten tons of equipment and explosives. The lake is inaccessible by road and can only be reached by foot or air.

Following a visit to the area yesterday morning, Vice Premier Hui Liangyu has said work on the lake should be a top priority, stating: ‘The Tangjiashan quake lake should be our most urgent task. It is threatening millions of lives in the area downstream and any negligence will cause new disasters to people who have already suffered the quake.’

In total, 158,000 people from 169 communities in 33 townships of Mianying will have to move from their homes if one third of the lake volume bursts its banks, according to an emergency plan from the Ministry of Water Resources.