Yongding River

The Yongding River (simplified Chinese: 永定河; traditional Chinese: same; pinyin: Yǒngdìng Hé; Wade Giles: Yungting River) is a river in northern China. It is one of the main tributaries in the Hai River system and is best known as the largest river to flow through Beijing Municipality.

Geography

The Yongding River is 650 kilometres (400 mi) in length and drains an area of 47,016 square kilometres (18,153 sq mi). It emerges from the Guancen Mountains (管涔山) in Ningwu County, Shanxi Province, where it is known as the Cangqian River (桑乾河) and flows northeast into Inner Mongolia and then heads southeast into Hebei Province.

In Huailai County, it fills the Guanting Reservoir, the biggest reservoir serving Beijing and takes on the name Yongding. It enters Beijing Municipality through the Xishan Mountains west of the city in Mentougou District and descends into the flatlands of Fengtai and Daxing Districts.

The river eventually flows back into Hebei Province and then on to Tianjin Municipality, where it meets the Hai River just before the latter enters the city and then empties into the Bohai Sea at Tanggu. Part of the river is diverted before the juncture with the Hai, and flows directly into the Bohai Sea. This channel is called the Yongding New River (永定新河).