Zhengguo Canal

Together with the Dujiangyan Irrigation System and Lingqu Canal, it is one of the three biggest water conservation projects built before the Qin dynasty in ancient China.

Historian Sima Qian in his Records of the Grand Historian wrote of the Zhengguo Canal: But Han heard that Qin was fond of embarking on enterprises, so with the intention of causing its energies to be dissipated and in order to prevent it from making an attack to the east, it accordingly dispatched a water engineer named Zheng Guo to give controversial advice to Qin by making it excavate a canal from the Jing River west of Mount Zhong as far as Hukou, from where it was to go east along the Northern Mountains and flow into the Luo.

When it was half completed the true purpose was realized, and Qin intended to kill Zheng Guo, but Zheng Guo said: ‘At first I was acting in order to cause dissension, but when the canal is completed it will surely be a benefit to Qin.’ Qin thought this was true, so in the end had the progress on the canal continued.

When the canal did make further progress, it was used to cause the stagnant waters to flow, and irrigate the salty land over an area of more than 40,000 qing, so that the harvest totalled one zhong per mou.

Thereupon the area within the passes was turned into fertile but uncultivated land, and there were no calamitous years, and thus Qin became rich and strong, and in the end unified the feudal states.