The Banqiao Reservoir Dam (板桥水库大坝) and Shimantan Reservoir Dam (石漫滩水库大坝) are among 62 dams in Zhumadian Prefecture of China's Henan Province that failed catastrophically in 1975 during a freak typhoon. Approximately 86,000 people died from flooding and another 145,000 died during subsequent epidemics.

Contents

1 History 2 Banqiao Flood 3 See also 4 External links

History

The Banqiao dam was built in the early 1950s on the Ru River as part of a project to control flooding. It had a storage capacity of 492 million cubic meters, with 375 million cubic meters reserved for flood storage. Cracks in the dam and sluice gates appeared after completion due to construction and engineering errors. They were repaired with advice from Soviet engineers and the new design, dubbed the iron dam, was considered unbreakable.

Chen Xing was one of China's foremost hydrologists and was involved in the design of the dam. He was also a vocal critic of the government dam building policy, which involved many dams in the basin. He had recommended 12 sluice gates for the Banqiao Dam, but this was scaled back to 5 and Chen Xing was criticized as being too conservative. Other dams in the project, including the Shimantan Dam, had similar reduction of safety features and Xing was removed from the project. In 1961, after problems with the water system surfaced, he was brought back to help. Xing continued to be an outspoken critic of the system and was again removed from the project.

Banqiao Flood

The Dam was designed to survive a 1-in-1,000-year flood. However, in August of 1975 a 1-in-2,000 year flood occurred, as a result of a freak typhoon. The sluice gates couldn't handle the overflow of water, partially due to sedimentation blockage. On August 8, early in the morning, the smaller Shimantan Dam broke upstream. A half hour later, at 1 AM, water crested at the Banqiao Dam and it too failed. This precipitated the failure of 62 dams in total.

The resulting flood waters caused a large wave several meters high to rush downwards into the plains below at nearly 50 kilometers per hour. Seven county seats (Suiping, Xiping, Runan, Pingyu, Xincai, Luohe, Linquan) were inundated, as were thousands of square kilometers of countryside and countless communities; evacuation orders had not been enforced and many people were caught completely unawares. The Jingguang Railway, a major artery from Beijing to Guangzhou, was cut off, as were other crucial communications lines. Nine days later there were still over a million people trapped by water, inaccessible to disaster relief, while epidemics and famine devastated the trapped survivors. Chen Xing was again brought back to the project and aided in clearing the river channels.

The Chinese government tried very hard to suppress information of the catastrophe. The first English reporting of details of the disaster, by Human Rights Watch, did not occur until 1995. Information today is more forthcoming [1] (http://news.163.com/2004w11/12746/2004w11_1101284865102.html).

Many of the dams have been rebuilt, including Banqiao in 1993.

See also

• Dam
• Disaster
• Flood
• Huai He (to which the Ru River is tributary)

External links

• HRW report (http://www.hrw.org/reports/1995/China1.htm)
• Exerpt from Silenced Rivers: The Ecology and Politics of Large Dams, by Patrick McCully (http://www.irn.org/basics/ard/srdamsafety.pdf)

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