Yinzhang Shier Qu

　　Yinzhang Shi'er Qu, twelve canals that divert water from the Zhanghe River, is located in today's Anyang City in Central China's Henan Province. Qu means canal. It was a large irrigation project built in the Warring States Period (403-221BC).

　　The project consisted of 12 canals that diverted water from the Zhanghe River, playing a great role in irrigating the surrounding fields. According to historical records, about 100,000 mu (1 mu = 1/15 hectare) of farmland benefited from the project shortly after its completion and surrounding areas became richer than other regions in ancient China.

　　In the late Eastern Han Dynasty (25-220), Cao Cao had the canal revamped and changed its name to Tianjing Yan (Yan means weir). Later, the project undertook further reconstruction and could irrigate more fields.

　　In 1959, a reservoir was built on the Zhanghe River, replacing the 2,300-year-old canal.