The rivers of Nepal
Three great snow-fed systems — Koshi, Gandaki and Karnali — the border Mahakali, and the hill-fed rivers in between. Each one mapped, with its length, source, tributaries, and the hydropower built on it.
Great systems
3
Koshi · Gandaki · Karnali
Rivers catalogued
20
incl. 4 trunk systems
Snow / glacier-fed
15
Himalayan & trans-Himalayan
Longest river
Karnali
≈507 km in Nepal
Hover any river to see its name; click to open its page. River courses are real centrelines from OpenStreetMap, clipped to Nepal and coloured by system.
Koshi system
The eastern system — Nepal's largest, draining Everest and Kanchenjunga
Gandaki system
The central system — Annapurna and Dhaulagiri, the deepest gorge
Karnali system
The western system — Nepal's longest, largely free-flowing river
Mahakali system
The far-western border river, shared with India
Southern / Mahabharat rivers
Rain- and spring-fed rivers rising in the Middle Hills
Three kinds of Nepali river
Where a river starts decides how it behaves — whether it runs year-round on snowmelt or swings wildly with the monsoon.
Trans-Himalayan & Himalayan
Rises on the Tibetan plateau and cuts through the Himalaya. Snow- and glacier-fed, these run strongly all year — the basis of big hydropower.
Mahabharat
Spring- and rain-fed, rising in the Middle Hills. Spring- and rain-fed, with sharp seasonal swings between flood and trickle.
Churia (Siwalik)
Seasonal, rising in the Siwalik (Churia) foothills. Often dry for much of the year, flashing into spate during the monsoon.
Nepal's rivers, answered
What are the three major river systems of Nepal?+
Nepal's three great snow-fed river systems are the Koshi (east), the Gandaki (centre) and the Karnali (west). All three rise in or beyond the high Himalaya and flow south into the Ganga in India. The Mahakali forms the far-western border, and a set of smaller Mahabharat-origin rivers (such as the Bagmati and West Rapti) rise in the Middle Hills.
What is the longest river in Nepal?+
The Karnali is Nepal's longest river, running about 507 km within Nepal (around 1,080 km to the Ganga). It rises near Mount Kailash and Lake Manasarovar in Tibet and is Nepal's largest essentially free-flowing river.
What is the largest river system in Nepal?+
The Koshi (Sapta Koshi) is Nepal's largest river system by drainage area and discharge. It gathers seven major Himalayan rivers and drains the highest terrain on Earth, including Mount Everest and Kanchenjunga.
Why are Nepal's rivers important?+
Nepal's rivers are the backbone of its economy: they hold one of the world's largest hydropower potentials, irrigate the Tarai plains, carry religious and cultural significance, and feed the Ganga basin that hundreds of millions of people depend on downstream.
What is the Sapta Koshi and the Sapta Gandaki?+
'Sapta' means seven. The Sapta Koshi is the seven rivers that combine to form the Koshi (including the Sun Koshi, Arun and Tamor), and the Sapta Gandaki is the seven that form the Gandaki (including the Kali Gandaki, Marsyangdi and Trishuli).
Sources & data note
River lengths and drainage figures are approximate, drawn from standard references and basin studies. The mapped river courses are real centrelines from OpenStreetMap, clipped to Nepal's boundary. Hydropower counts are matched from our own source-cited hydro database.