Dujiangyan Irrigation Project

The Dujiangyan Irrigation Project is a long-established water conservation works. It is 56 kilometers (34.8miles) west of Chengdu at Dujiangyan city lying in the middle reach of Minjiang River, which is the longest tributary of Yangtze River.
On November 29th, 2000, Dujiangyan was listed on world cultural heritages by UNESCO.

Since ancient times the Minjiang River has surged downward from Mt. Minshan thrusting itself into the Chengdu Plain. When reaching the flatlands the rivers speed slowed down abruptly. Thus the watercourse filled up with silt making this area extremely vulnerable to flooding. The people living on the Chengdu Plain consequently suffered a great deal from frequent floods.
Around BC 250 during the Warring States Period, Libing, a governor of Shu in Qin state (present Sichuan Province) with his son directed the construction of Dujiangyan. The governor gave up the old ways of dam building which was simply try to catch the floodwaters. Instead he employed a new method by channeling and dividing the water to harness the Minjiang River. He accomplished this by separating the project in to two main parts: the headwork and the irrigation system. The project effectively put the flooding waters under control.