Zhengguo Canal 郑国渠

About Zhengguo Canal

Zhengguo Canal (郑国渠) is an irrigation canal dug by the state of Qin in the late Warring States period across the northern Guanzhong Plain (关中平原). Its head-works site lies north of Shangran Village (上然村) in Wangqiao Town (王桥镇), Jingyang County (泾阳县), Xianyang, Shaanxi.

The intake stood at Hukou (瓠口), west of Mount Zhong (仲山), where the Jing River (泾河) passes through the Northern Mountains (北山) and enters the plain north of the Wei. From there the main channel ran east along the southern foot of the hills to the Luo River (洛水). The Records of the Grand Historian (史记) put its length at "more than 300 li"; modern studies estimate 124 to 126 km. The Jing carries heavy silt, and the canal spread that muddy water over low, salty land, both watering crops and building up and enriching the soil.

Work began in 246 BC, the first year of King Zheng of Qin. The engineer Zheng Guo (郑国) had been sent by the state of Han to tie up Qin's labour and supplies; when the plan came to light, he argued that the canal would serve Qin all the same, and the king let him finish it. The canal was completed about ten years after work began. As the Jing cut its bed deeper, later builders kept moving the intake upstream: the Han Bai Canal (白渠), Song, Yuan, Ming and Qing successors, and finally the Jinghui Canal (泾惠渠), begun in 1930 under the engineer Li Yizhi (李仪祉) and carrying water from 1932.

The Shaanxi Cultural Heritage Administration lists eleven intakes of different dynasties at the site, among them the Qin canal head, the Han Bai Canal head and the Tang Three Bai Canals head, along with sixteen steles recording works to draw water from the Jing. The site was placed in the fourth batch of national key protected cultural sites in 1996. In 2016 the International Commission on Irrigation and Drainage added the canal to its World Heritage Irrigation Structures list, a register separate from UNESCO's World Heritage List. The same bureau notes that the Zhengguo Canal tourist scenic area lies outside the protected zone of the head-works site.

What to look for

• Hukou (瓠口), the gorge mouth where the Jing River leaves the Northern Mountains, the site of the Qin intake
• The Qin canal head, the earliest of eleven intakes built by successive dynasties
• The Han Bai Canal (白渠) head and the Tang Three Bai Canals (三白渠) head
• Sixteen steles on Jing River water works of different dynasties, under a protective roofed corridor
• Traces of a spillway channel south of the old channel at the canal head, read as an outlet for floods, surplus water and silt

Location & getting there

Getting to Zhengguo Canal

• Search for 郑国渠 with 咸阳市 and 泾阳县.