Catastrophic series of floods due to failure of multiple dams in Henan, China
The 1975 Banqiao Dam failure was one of history's deadliest dam collapses, killing tens of thousands and remaining concealed by Chinese authorities for decades.
Key Facts
- Dams collapsed
- 62 (including Banqiao Dam)
- Estimated death toll range
- 26,000–240,000 deaths
- Area affected
- 12,000 km²
- Population affected
- 10.15 million people
- Houses collapsed
- 5–6.8 million houses
- Documents declassified
- 2005
By the Numbers
Location
Cause → Event → Consequence
Typhoon Nina made landfall and delivered over 1,060 mm of rainfall near the typhoon center in a single day, far exceeding the Banqiao Dam's design threshold of 300 mm per day. Structural weaknesses from Great Leap Forward construction practices, Soviet-advised dam design focused on water retention over flood prevention, and ecological degradation from Maoist agricultural policies compounded the vulnerability.
On 8 August 1975, the Banqiao Dam and 61 other dams across Henan Province collapsed in rapid succession, unleashing catastrophic flooding across approximately 12,000 km² affecting some 30 cities and counties. The floods inundated a total population of around 10.15 million people and destroyed millions of homes, constituting the third-deadliest flood in recorded history.
The disaster killed between 26,000 and 240,000 people and destroyed 5 to 6.8 million houses. The Chinese government suppressed information about the catastrophe throughout the Cultural Revolution era; details only became public in the 1990s through a book prefaced by former Minister of Water Resources Qian Zhengying, and official documents were not declassified until 2005.
Human Cost
Each dot represents approximately 10,000 deaths. Total estimated: 26,000 (flood)
Range: 26,000 – 240,000