The Banqiao Dam Failure, 1975
The Banqiao Dam was built on the Ru River as a means to prevent future flooding of the Huai River Basin in the Zhumadian Prefecture of Henan Province in central China, which had been severely flooded in 1950. Construction of the dam was started in 1951 and was completed the following year. The slightly smaller Shimantan Dam on the Hong River, and many other smaller dams situated within this river system, were built for the same project. By 1954, both the Banqiao and Shimantan dams were sporting cracks due to substandard design and construction methods. Subsequently, with the help of Soviet engineers, both dams were repaired and extended, however not quite as well as was advised.
A hydrologist by the name of Chen …show more content…
This meant that all the rain was now dropped in a single area, resulting in more than the region’s annual rainfall of 800 mm to be dropped in 24 hours. This amount of rainfall was completely unprecedented, and was deemed to be a flood that might happen once every 2000 years. In total, Typhoon Nina dropped 1631 mm of water over a 3 day period, far more than the Banqiao and other dams had ever been designed to handle. After the first deluge of water on the first day, all the sluice gates were opened on the Banqiao Dam, however a silt build up prevented them from draining the dam as effectively as they should have. By the evening of August 7, 8 dams had already collapsed in the area, some of which would have added to the enormous inflow of water into the Banqiao …show more content…
When this flood did happen though, there weren’t any emergency plans in place to deal with the flooding, and so thousands of people were left stranded atop some of the more sturdy building’s roofs and small outcrops. Communication and transportation infrastructure had subsequently been destroyed in the Zhumadian Prefecture, so even the army’s emergency crews were unable to provide assistance in many of the areas for up to 2 weeks after the
The Banqiao Dam was built on the Ru River as a means to prevent future flooding of the Huai River Basin in the Zhumadian Prefecture of Henan Province in central China, which had been severely flooded in 1950. Construction of the dam was started in 1951 and was completed the following year. The slightly smaller Shimantan Dam on the Hong River, and many other smaller dams situated within this river system, were built for the same project. By 1954, both the Banqiao and Shimantan dams were sporting cracks due to substandard design and construction methods. Subsequently, with the help of Soviet engineers, both dams were repaired and extended, however not quite as well as was advised.
A hydrologist by the name of Chen …show more content…
This meant that all the rain was now dropped in a single area, resulting in more than the region’s annual rainfall of 800 mm to be dropped in 24 hours. This amount of rainfall was completely unprecedented, and was deemed to be a flood that might happen once every 2000 years. In total, Typhoon Nina dropped 1631 mm of water over a 3 day period, far more than the Banqiao and other dams had ever been designed to handle. After the first deluge of water on the first day, all the sluice gates were opened on the Banqiao Dam, however a silt build up prevented them from draining the dam as effectively as they should have. By the evening of August 7, 8 dams had already collapsed in the area, some of which would have added to the enormous inflow of water into the Banqiao …show more content…
When this flood did happen though, there weren’t any emergency plans in place to deal with the flooding, and so thousands of people were left stranded atop some of the more sturdy building’s roofs and small outcrops. Communication and transportation infrastructure had subsequently been destroyed in the Zhumadian Prefecture, so even the army’s emergency crews were unable to provide assistance in many of the areas for up to 2 weeks after the