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.