41. Banqiao Reservoir Dam
Location: Henan Province, China
Year of Fail: 1975
Built in 1952, the government deemed Banqiao “unbreakable” despite early signs of poor construction and a leading hydrologist’s warning that there were too few water-regulating gates. While these errors certainly contributed to the dam failure in 1975, the super typhoon that preceded the break may have destroyed even a perfect dam. After a year’s worth of rain fell in 24 hours, a message was sent to open the dam gates. The information was never received and Banqiao’s walls ultimately gave way, precipitating the failure of 62 dams in total. The resulting flood caused a wave 6.2 miles wide to rush onto the plains below at over 30 miles per hour. Approximately 26,000 people died during the flooding and another 145,000 perished during ensuing famine and epidemics.