Hai River

The Hai River is the largest water system in north China, and its main channel is what makes Tianjin a river city. The channel runs from the Zibei confluence, or Sanchahekou, to the Dagu mouth, and its length is given variously as 76, 72 or 73 kilometres; the city's own account uses 73 kilometres from Sanchahekou to the Bohai and calls it the mother river. It gathers the five upstream rivers, the North Canal, Yongding, Daqing, Ziya and South Canal, together with more than three hundred smaller streams, and its basin covers 318,000 square kilometres across seven provinces, autonomous regions and municipalities. The name Haihe first appears in 1613, in farm rules written by the scholar Xu Guangqi.