230,000 Died in a Dam Collapse That China Kept Secret for Years
Workers stood along the top of Banqiao Dam, some 150 feet above the valley’s floor, desperately trying to repair its crest as rain from Typhoon Nina fell for a third straight day. After battering Taiwan, the storm had moved inland where it was expected to dissipate, but Nina turned north instead, reaching the Huai River basin on Aug. 5, 1975, where a cold front blocked its progression. Parked in place, the typhoon generated more than a year’s worth of rain in 24 hours.
By the time night fell on Aug. 8, as many as 65 area dams had collapsed. But despite the fact that water levels at the Banqiao Dam had far exceeded a safe capacity, and a number of sluice gates for controlling water flow were clogged with silt, authorities felt confident they’d skirt disaster. After all, the Soviet-designed dam had been built to survive a typhoon — a once-every-1,000-year occurrence that could dump 11 inches of rain per day. Unfortunately, Typhoon Nina would prove to be a once-every-2,000-year storm, bearing down with enough force to cause the world’s deadliest infrastructure failure ever.
https://www.ozy.com/flashback/230000-died-in-a-damn-collapse-that-china-kept-secret-for-years/91699