Dujiangyan Irrigation System

The irrigation system to be found near the town of Guanxian on the upper reaches of the Minjian river, 55km/34mi northwest of Chengdu, was constructed in 250 BC by Li Bing, prefect of Sichuan at the time of the Warring Kingdoms, in order to prevent catastrophic flooding. He ordered the river to be divided up by means of earth dams, with one section branching out into tributaries and canals which served to irrigate the fields. The whole complex is made up of the ''Fish's Jaws'' (Yuzhui), which functions as a watershed and dike, the weir known as ''Flying Sands'' (Feisha Yan) and the canal, the ''Neck of the Precious Bottle'' (Baoping Kou). This ingenious system has meant that the Minjian has never again flooded its banks during the last 2200 years, and the Chengdu Plain of central Sichuan has become one of China's most fertile regions.