A Dam Disaster That Killed Hundreds of Thousands
On August 6th, 1975, as water levels rose in Banqiao’s reservoirs, officials requested authority to open the dam to relieve the pressure. They were turned down because of ongoing flooding downstream. The request was finally approved the following day, the 7th, but the telegram failed to reach Banqiao. In the early hours of August 8th, the water crested a foot above the dam’s wave protection wall, and it collapsed. The resultant Banqiao Disaster was history’s worst structural failure. The Banqiao Dam was one of 62 dams that collapsed because of Typhoon Nina. When it gave way, it released almost sixteen billion cubic meters of water. They produced a wave 6.2 miles wide and 10 to 23 feet high, that rushed downstream at 31 miles an hour. It left a swath of devastation 9.3-miles-wide and 34-miles-long.
The collapsed dam unleashed history’s third deadliest flood ever, devastated thirty cities and counties, inundated three million acres, and destroyed almost seven million houses. Over ten million people were impacted, and the death toll might have been as high as 240,000. The disaster occurred at the tail end of Mao’s regime and his Cultural Revolution. That was yet another bad idea that produced years of turmoil, because Mao wanted to retain power by getting rival communist factions to fight each other, and leave him as arbitrator. China’s government did its best to hide the extent of the disaster. Solid information – or as solid as governmental information ever gets in China – did not emerge until the 1990s. The extent of the disaster finally came to light when a former Minister of Water Resources wrote a preface for a book, in which details were revealed for the first time.