Tung Chung River is to the southwest of Tung Chung New Town in Lantau and is a remaining natural river in Hong Kong. The whole river course is pristine from its sources to its estuary and bay, except the channelized sections from Shek Lau Po to Wong Ka Wai and where it crosses Tung Chung Road for flood prevention purposes.
Tung Chung River has catchments around its east and west branches, with a basin area of 11 square kilometres. The west branch is known as Tso Stream, which begins between Lantau Peak and Sunset Peak. North Fung Tai Stream, the east branch, originates from the west of Sunset Peak. The two branches flow through the villages of Shek Mun Kap, Mok Ka, Fong Yuen, Shek Lau Po etc., then merge at the end of the valley between Ngau Au and Wai Ka Wai, finally flowing into the 80 hectares Tung Chung Bay.
Tung Chung River is one of the few rivers in Hong Kong with good water quality. It is one of the major rivers feeding Shek Pik Reservoir. The Environmental Protection Department reported an E. coli level of 760/100ml in Tung Chung River, grading it as “excellent” in water quality in 2022. Moreover, Tung Chung River has very high ecological value with many species of native freshwater fish recorded, including the Beijing Thick-lipped Barb. The large areas of mangroves and mudflat at the estuary are also habitats for many valuable species. Horseshoe crabs, seahorses, pipefishes, and a number of fish species of commercial value reproduce and nurse their young at Tung Chung Bay.