Some 80,000 people died, mostly in landslides and collapsing buildings, in the earthquake which rocked China’s Sichuan province on 12 May, yet it could have been so much worse. Probably nowhere on Earth are there so many large dams in an area of such seismic risk. Engineers are astounded that none of the 390 hydroelectric dams damaged in the magnitude 7.9 quake actually collapsed.
The biggest potential disaster was averted at the 158-metre-high Zipingpu dam, 17 kilometres from the quake’s epicentre. Holding back more than a cubic kilometre of water, it is just upstream of Dujiangyan, a town of…
