River · Nha Trang
Cai River (Nha Trang)
Sông Cái Nha Trang
The Cai River (Sông Cái Nha Trang) is a river in Khanh Hoa province, Vietnam. Its length is given as 84 km by Vietnamese Wikipedia's article on the river[1] and by Wikidata[2], and as 79 km, for the same river from the same source mountain, by Vietnamese Wikipedia's article on Khanh Hoa province[7]. It rises on Hon Gia Le at 1,812 m in the mountains west of Nha Trang, reaching the sea at Cua Lon, also called Dai Cu Huan, on Nha Trang Bay[1].
Published figures for its basin disagree: Vietnamese Wikipedia gives 1,732 km²[1] and English Wikipedia gives 1,904 km²[3]. The river carries about 1.79 km³ of water a year, equivalent to 940 mm of runoff, of which about 73 percent passes between October and December[1].
In the lower course the river divides at Xuan Lac and the channels rejoin at Con De, also called Con Ngoc Thao[1]. The coastal Tran Phu road crosses it on a bridge completed on 2 September 2002[5].
Course
The Cai River rises on Hon Gia Le at an elevation of 1,812 m and runs 84 km to the sea[1][2]. English Wikipedia places the source at 12.34389°N, 108.74833°E and the mouth at 12.26333°N, 109.19778°E[3].
The upper course carries a string of small falls, among them Dong Trang, Ong Hao, Da Lua, Nhet, Mong, Vong, Dang Xay, Tham Du, Ngua, Hong Tuong, Trau Dung, Giang Che, Trau A, Nai, Rua and Hom[1].
At Xuan Lac the river divides. One branch running east and south has largely silted up. The main branch runs east and north and splits again: one channel passes Ngu Truong and Ha Ra to the Dai Cu Huan mouth, the other passes Xom Bong and Cu Lao to the Nha Trang mouth. The two rejoin at Con De, also called Con Ngoc Thao[1].
Hydrology
The basin figure is not settled. Vietnamese Wikipedia gives 1,732 km²[1]; the English Wikipedia stub gives 1,904 km² and flags the figure as uncited[3]. Annual flow is about 1.79 km³, a runoff depth of 940 mm and a module of 29.8 litres per second per square kilometre[1].
Flow is strongly seasonal. About 73 percent of the annual total passes in the flood season from October to December, at a module of 240 litres per second per square kilometre, and about 27 percent in the dry season from January to September, at 10 to 18 litres per second per square kilometre[1]. The basin holds 7 main tributaries and 15 tributaries longer than 10 km[1].
The Tran Phu bridge
The Tran Phu bridge carries the coastal Tran Phu road over the Cai River at Nha Trang[5]. It is 458.27 m long and 22 m wide and carries four lanes[5]. Construction began on 3 September 1999 and the bridge was completed on 2 September 2002[5].
Floods
The river floods in the October to December season, which carries about 73 percent of its annual flow[1]. On 17 November 2025 the Cai River at Nha Trang stood at 9.44 m at the Dong Trang gauge, 0.06 m below alarm level 2, while the Dien Phu gauge stood at 5.51 m, 0.01 m above alarm level 3[6].
The flood peaked at Dong Trang at 13.14 m at 05:00 on 20 November 2025, which was 2.14 m above alarm level 3 and 0.28 m below the historic level of 13.42 m recorded in 2009[4].
Questions and answers
How long is the Cai River at Nha Trang?
How large is the river's basin?
What was the highest flood recorded on the river?
13.42 m at the Dong Trang gauge in 2009. The November 2025 flood peaked at 13.14 m there at 05:00 on 20 November, 0.28 m lower[4].
Sources
Every figure in this article is cited to one of these pages, listed in order of first use, with the date it was read.
See also
- Nha TrangFormer city
- Dien KhanhFormer district
- Po Nagar Cham TowersTemple
- Hon BaMountain
- Khanh Le PassMountain pass
- Typhoon Damrey (2017)Event