[freebeard]

They have a history of problems with floods. 1938:

To stop further Japanese advances into western and southern China, Chiang Kai-shek, at the suggestion of Chen Guofu, determined to open up the dykes on the Yellow River near Zhengzhou. The original plan was to destroy the dyke at Zhaokou, but due to difficulties at that location, the dyke at Huayuankou, on the south bank, was destroyed on June 5 and June 7 via excavation,[3] with waters flooding into Henan, Anhui, and Jiangsu. The floods covered and destroyed thousands of square kilometres of farmland and shifted the mouth of the Yellow River hundreds of kilometres to the south. Thousands of villages were inundated or destroyed and several million villagers driven from their homes and made refugees. An unknown number of Japanese soldiers were killed by the flood. An official Kuomintang post-war commission estimated that the total number of casualties may be as high as 800,000 killed by the flood.[4]

https://en.wikipedia.org/wiki/1938_Yellow_River_flood

Great Flood (China) - Wikipedia
https://en.wikipedia.org/wiki/Great_Flood_(China)
The Great Flood of Gun-Yu (Chinese: 鯀禹治水), also known as the Gun-Yu myth, was a major flood event in ancient China that allegedly continued for at least two generations, which resulted in great population displacements among other disasters, such as storms and famine. People left their homes to live on the high hills and mounts, or nest on the trees.

There was an episode around WWII where they bombed a dam to relieve pressure on other dams, but [citation needed].