MAJOR RIVERS OF NEPAL
Nepal's rivers can be broadly divided into three categories in accordance with their origins. The first category comprises the three main river systems of the country-the Koshi, Gandaki and Karnali river systems, all of them originating from glaciers and snow-fed lakes.
The Koshi river system consists of the Tamor, Arun, Dudhkoshi, Likhu, Tamakoshi, Sunkoshi and Indravati rivers. Of these, the Arun and Sunkoshi originate in Tibet. The confluence of these rivers is at Tribeni (near Dharan) in Sagarmatha Zone. Flowing for almost 10kms through a narrow gorge before entering the plains, the "Sapta Kosi" or the "Koshi" swollen with the waters of the seven rivers finally merges into the Ganges.
The Gandaki river system in central Nepal consists of the Kaligandaki, Budhigandaki, Marsyanghi, Trishuli, Seti, Madi and Daraundi rivers. The Kaligandaki is the longest river and the Trishuli, the main tributary of this system.