Dujiangyan is a waterwork that leads water off without a dam. It has three parts: the Fish Mouth divides the water, the Flying Sand Weir clears the silt, and the Bottle-Neck Channel draws the water in. Working together, they lead the water into the irrigated land while the silt is carried off automatically.
About 256 BCE, Li Bing, governor of Shu Commandery of Qin, oversaw the building of Dujiangyan.
After the Han, Dujiangyan was repaired every year, and the Chengdu plain became the "Land of Abundance". The work is still in use today and irrigates more than six hundred thousand hectares of farmland.
Dujiangyan Water Project is the class in the chapter on Infrastructure on the Dujiangyan waterworks, created by Li Bing and his son. Three works, the Fish Mouth, the Flying Sand Weir and the Bottle-Neck Channel, led the water off without a dam and cleared the silt automatically, and made the Chengdu plain a land of plenty secure against drought and flood.
