King Zhao of Qin commissioned the project, and the construction of the Dujiangyan harnessed the river using a new method of channeling and dividing the water rather than simply damming it.

Qin hydrologist Li Bing investigated the problem and discovered that the river was swelled by fast flowing spring melt-water from the local mountains that burst the banks when it reached the slow moving and heavily silted stretch below.

[4] One solution would have been to build a dam, but the Qin wanted to keep the waterway open for military vessels to supply troops on the frontier,[5] so instead an artificial levee was constructed to redirect a portion of the river's flow and then to cut a channel through Mount Yulei to discharge the excess water upon the dry Chengdu Plain beyond.

The levee was constructed from long sausage-shaped baskets of woven bamboo filled with stones known as Zhulong[7] held in place by wooden tripods known as Macha.

Li Bing devised an ingenious method of using fire and water to rapidly heat and cool the rocks, causing them to crack and allowing them to be easily removed.

The construction is also credited with giving the people of the region a laid-back attitude to life;[12] by eliminating disaster and ensuring a regular and bountiful harvest, it left them with plenty of free time.

[13] Turmoil surrounding the conquering of Chengdu by peasant rebel leader Zhang Xianzhong in 1644, and the Ming-Qing transition more generally, led to depopulation and the deterioration of the Dujiangyan irrigation system to the point where rice cultivation was set back for decades.

[24] In 1803 during the Qing dynasty a local man named He Xiande and his wife proposed the construction of a replacement, made of wooden plates and bamboo handrails, to span both streams and this was nicknamed Couple's Bridge in their honour.

[25] The Dujiangyan irrigation system is located in the western portion of the Chengdu flatlands, at the junction between the Sichuan basin and the Qinghai-Tibet plateau.

[2] The Dujiangyan irrigation system is located at the turning point of the two topographic steps of the western plateau mountains and the Chengdu Plain.

[26] The Dujiangyan irrigation system was built at the entrance of Minjiang River, with an average annual inflow of 15.082 billion cubic meters.

[33] Guanlantin Pavilion stands above the complex and is inscribed with wise words from Li Bing such as, When the river flows in zigzags, cut a straight channel; when the riverbed is wide and shallow, dig it deeper.

Following Li Bing's death a hall was established here in his honour and the temple was renamed to commemorate the dragon fighting legends that surrounded him.

[35] It is here that Erlang Shen, the legendary son of Li Bing, is said to have chained the dragon that he and his seven sworn brothers had captured in an ambush at the River God Temple when it came to collect a human sacrifice.

[36] During the East Han dynasty a statue of Li Bing was placed in the river to monitor the water flow, with the level rising above his shoulders to indicate flood and falling beneath his calves to indicate drought.