When Karl Marx printed his pre-capitalist economic formations in 1858 and coined the idea of the “Asian mode of production”, a social system that, unlike Mediterranean slavery, was based on absolute dominance of water resources, Dujiangyan carried already more than 2000 years built on the Minjiang River protecting (and feeding) the Chengdu Plain.
In fact, when the Chinese emperor Qin Shihuang ordered the construction of the Great Wall to begin in 254 BC, the massive Dujiangyan sea wall and its irrigation system had been finished protecting the heart of Sinchuan for years and making it one of the centers most important economic in the country. Even today, this network of barriers and channels excavated by fire in the mountains continue to irrigate more than 5,300 square kilometers of land, which is, due to its size and age, one of the most impressive hydraulic works in human history.
Imagine and build the impossible
The floods of the Min, as it happened with those of the Nile, recurrently marked the history of the Sichuan province since the first human settlements of which we have evidence in the fifteenth century BC. However, it was around the 5th century BC, when China was still a jumble of Warring Kingdoms, that the needs of war required ensuring the production of the Chengdu Plain.
Governor Qin ordered Li Bing, a hydraulic engineer, to discover the source of the problem and concluded that it was the rapid thawing of the snows that increased the flow of the river in such a way that the water took advantage of the first plain to expand with freedom. The solution was simple: make a dam.
But it couldn’t be. The Qin needed to ensure that the course of the Min remained navigable in order to move troops not only through the province but through the Yantze, the true demographic and productive hub of mainland China. So Li Bing had to get imaginative and planned the raising of an artificial levee, a jetty, that would divide the river in two and protect the plain along with a huge canal dug into Mount Yulei and that would allow some of the water to be redirected before arriving. to the plain, turning it into the driest parts of the region.
With 100,000 silver taels, Li Bing and his team began building the levee by braiding long sausage-shaped bamboo baskets and filling them with stone. But that was the simple part: the real problem was the channel dug into the mountain. As you can imagine, around 200 BC the tools that the Chinese hydraulic had were very limited.
Without gunpowder, workers had to light large bonfires next to the rock and heat it as much as possible, then pour cold water and take advantage of thermal shock to create cracks to work with. It took eight years to carve the 20-meter-wide channel through the mountain. Since then, Sinchuan became the great productive center of the country and, thanks to this, the Qin won the war marking the origin of Imperial China; that is, of what we know today as China.
In 2000, UNESCO declared the Li Bing irrigation system a World Heritage Site. It is not for less, as noted above, even today it is still operational. However, beyond its spectacular nature and the technical feat that its construction entailed, it is a key example of how engineering can play an essential role in the course of human history. Much more than we could ever imagine.