Banqiao dam failure in 1975, Henan, China

The Banqiao Reservoir Dam in Henan province failed in 1975 caused more casualties than any other dam failure in history at an estimated 230,000 deaths and 11 million displaced. The dam was later rebuilt.


Description

In response to severe flooding and to ensure electrical power generation, China built the Banqiao Dam in the Huai river basin of the Henan province. It was completed in 1952. However, they never imagined the dangers that would follow. [1] Due to construction and engineering errors, numerous cracks in the dam appeared after completion and were repaired by Soviet engineers. Chen Xing, one of China’s foremost hydrologists, was involved in the design and was a vocal critic of the dam’s final construction as well as the government’s policy. Chen had recommended twelve sluice gates for the dam, but only five were installed. Chen was involved in other dam projects, but due to his continuing voicing of safety concerns related to design and construction practices, he was removed from the projects.

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Basic Data
NameBanqiao dam failure in 1975, Henan, China
CountryChina
ProvinceHenan
SiteZhumadian
Accuracy of LocationHIGH local level
Source of Conflict
Type of Conflict (1st level)Water Management
Type of Conflict (2nd level)Dams and water distribution conflicts
Specific CommoditiesElectricity
Water
Project Details and Actors
Project DetailsThe dam was completed in 1952 as part of a campaign to “Harness the Huai River” and its tributaries after severe flooding in previous years. During the 1950s, over 100 dams and reservoirs were built just in Zhumadian Prefecture of Henan Province along with Banqiao. When the Great Leap Forward began in 1958, the campaign was held up as a national model to “give primacy to water accumulation for irrigation." [3]. The total capacity of the reservoir was 492 million m3 with 375 million m3 reserved for flood storage. The dam was made of clay and was 24.5 meters high. The maximum discharge of the reservoir was 1742 m3/s. Cracks in the dam and sluice gates appeared after completion due to construction and engineering errors. They were repaired with the advice from Soviet engineers and the new design, dubbed the iron dam, was considered unbreakable. Chen Xing (陈惺), one of China's foremost hydrologists, involved in the design of the dam, was also a vocal critic of the government's dam building policy, which involved many dams in the basin.

The dam was designed to survive a once-in-1000-years flood (300 mm of rainfall per day) but a once-in-2000-years flood occurred in August 1975, following the collision of Typhoon Nina and a cold front. The typhoon was blocked for two days before its direction ultimately changed from northeastward to westward. As a result of this near stationary thunderstorm system, more than a year's worth of rain fell within 24 hours (1060 mm), exceeding the average annual precipitation of about 800 mm. The Banqiao Reservoir was designed with a capacity of only 492 million cubic meters but it had to accommodate more than 697 million cubic meters of floods, with half the recommended gates.

The cascade of dams that had been built on the Huai River and its tributaries to reduce flood risks ultimately made the flooding deadlier and the rescue effort more difficult. "Henan Flood Disaster in August 1975", the government-sponsored book, records the deadly flood with stark figures. “Two large dams, Banqiao and Shimantan, plus two medium-sized and 58 small ones were broken down by the flood. Nearly 10 billion cubic meters of water created 10-meter-high waves and ravaged the whole Zhumadian area in a matter of hours. More than four million people in 30 counties were trapped in the water, with five million houses and one million animals washed away" [4]
Type of PopulationRural
Potential Affected Population11,000,000
Start Date08/08/1975
Relevant government actorsGovernment of China
Environmental justice organisations and other supportersChen Xing, one of China’s foremost hydrologists, was involved in the design and was a vocal critic of the dam
The Conflict and the Mobilization
Intensity of Conflict (at highest level)LOW (some local organising)
When did the mobilization beginMobilization for reparations once impacts have been felt
Groups MobilizingFarmers
Neighbours/citizens/communities
Local scientists/professionals
Forms of MobilizationCreation of alternative reports/knowledge
Media based activism/alternative media
Asking for help after the disaster had happened. It seems that news of the terrible event were silenced in China.
Impacts
Environmental ImpactsVisible: Floods (river, coastal, mudflow), Large-scale disturbance of hydro and geological systems, Reduced ecological / hydrological connectivity
OtherDam failure
Health ImpactsVisible: Accidents, Exposure to unknown or uncertain complex risks (radiation, etc…), Deaths
OtherThe largest dam failure ever, over two hundred thousand deaths.
Socio-economic ImpactsVisible: Displacement, Loss of livelihood, Specific impacts on women, Violations of human rights, Land dispossession, Loss of landscape/sense of place
Outcome
Project StatusIn operation
Pathways for conflict outcome / responseLittle was done to repair the enormous environmental and social damage. This was the largest dam failure in the world. The dam was rebuit.
Do you consider this as a success?No
Why? Explain briefly.After the failure of the dam and the tragedy, the dam was rebuilt. There was no possible compensation for hundreds of thousands dead or displaced.
Sources and Materials
References

Patrick McCully, Silenced Rivers (description of the Banqiao disaster), p. 115-117.

Links

[1] William Tyrrell, Banqiao Dam Failure. 20th July 2016
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[2]https://en.wikipedia.org/wiki/Banqiao_Dam
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People’s Daily,30 years afterwards, 1 Oct 2005
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[3]The Forgotten Legacy of the Banqiao Dam Collapse. 2013-02-08. The Economic Observer (with a summary of current development in dam building in China, 40 years afterwards).
[click to view]

[4] News China. Dams in Distress. In 1975, over 60 dams collapsed after a rainstorm in Zhumadian city, Henan Province, causing the world’s worst ever technological disaster. Recent revelations about the incident have brought scrutiny to thousands of potentially unstable dams in China. October 2012 Issue | by Xie Ying
[click to view]

Media Links

A video simulating the Banqiao dam failure disaster
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Other Documents

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Meta Information
Last update08/06/2017
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