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Dujiangyan Irrigation System

The Dujiangyan Irrigation System (58 km (36 mi) away from downtown Chengdu) is the oldest existing irrigation project in the world with a history of over 2000 years diverting water without a dam to distribute water and filter sand with an inflow-quantity control. The system was built by Libing and his son. The irrigation system prevents floods and droughts throughout the Plain of Chengdu.