The river rises near Tibet and is joined by the Bhoti Kosi just downstream from Barbesi. Most raft trips start at Dolaghat. The Sun Kosi flows eastwards in Nepal through the great valley between the Mahabharat Lekh mountains and the Himalayas. The volume increases considerably draining flows from his Himalayan tributaries. In November, the flow at Dologhat is about 100 cumecs. Lower down the river, through the big rapids of the Jungle Corridor, it would be about 400 cumecs, which is appr. 11,000 cft, a typical low flow on the Grand Canyon of the Colorado.
At the end at Chatra, the flow is a super 800 cumecs, in November, which makes it one of the major rivers of the world in monsoon. A nice thing about Sun Kosi is that the general standard of the river gets progressively harder as you descend it so there is time to practice your skills on easy water before the more interesting, bigger and continuous rapids lower down the river.
From : Dologhat Alt. 620 m
To : Chatra Alt. 115 m
Distance : 272 kms
River days : 6-10 days
From Katmandu : 3 hours
Difficulty in November : Class 4- (5-)
Average gradient : 0,2 % (10 ft a mile)
Est. max. gradient : 0,6 %
Volume in November : 400 cumecs
Best season : Oct > Dec and Mar > May
Day 01 : Drive from Katmandu to Dolaghat and raft to Taramg Gaon, Timal Bensi Camp.
Day 02 : Raft Timal Bensi to Roshi Khola near Dunja Village.
Day 03 : Raft from Dunja Village to the village of Khurkot
Day 04 : Raft from Khurkot to Oxbox Section beach.
Day 05 : Raft from Oxbox Section to the confluence of Dudh Koshi.
Day 06 : Raft from the junction of Dudh Koshi to Rasuwa Khola.
Day 07 : Raft to broad beach bordered by a 400 ft high waterfall or Kampu Ghat.
Day 09 : Raft to Tribenighat, where the Arun and Tamur join the Sun Kosi.
Day 09 : Raft to Chatara, end of the rafting. Drive to Dharan in the afternoon.
Day 10 : Drive back to Katmandu.