Dujiangyan has maintained its immense effectiveness over the past two thousand years thanks to the successive dynasties' emphasis on hydraulic engineering.
During the reign of Emperor Ling of Han, the positions of "Du Shui Chuan" and "Du Shui Chang" were established to oversee the maintenance of the key dam project; during the Shu Han period, Zhuge Liang appointed Yan Guan and drafted 1,200 laborers to manage protection efforts. In subsequent dynasties, the county magistrate where the dam's headworks were located was designated as the chief overseer, and by the Song Dynasty, the annual repair system still in use today was formalized.
Moreover, advancements in foundational materials—from early bamboo cages and bricks to modern reinforced concrete—have ensured maximum structural stability.
Generally speaking, rainfall in this region is not a concern, but this year, the rains have persisted unusually long.
