Koshi system · Himalayan

Tamor

तमोर

The easternmost of the seven Koshis, draining Kanchenjunga.

River system: Koshi
Type: Himalayan
Length: ≈192 km
Source: The Kanchenjunga massif in Taplejung, far-eastern Nepal
Outlet: Joins the Sun Koshi and Arun at Tribeni
Provinces: Koshi

The Tamor drains Nepal's far east — the Nepali flanks of Kanchenjunga, the world's third-highest mountain. It rises in Taplejung district, and its glacier-fed headwaters are protected by the Kanchenjunga Conservation Area, 2,035 km² established in 1997, which adjoins protected land across the borders in both Tibet and Sikkim.

Running south-west through the deep hills of Taplejung, the river gathers the Mewa, Maiwa and Kabeli before meeting the Arun and Sun Koshi at Tribeni — the easternmost of the Sapta Koshi's seven rivers. For its size it punches above its weight: about 19% of the Sapta Koshi's total water comes down the Tamor.

The trek to Kanchenjunga Base Camp follows its valley, and the lower Tamor is one of Nepal's finest wilderness rafting runs, joining the combined Koshi just above the Chatara gorge. Its tributaries — the Kabeli in particular — carry a growing cluster of run-of-river hydropower plants.

Main tributaries

MewaMaiwaKabeli

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The Tamor (highlighted) shown with the rest of the Koshi system. Real river courses from OpenStreetMap — hover to label, click to switch river.

The power it holds

Hydropower on the Tamor

13 catalogued plants on or fed by this river, 883 MW in total. Tap any plant for its full profile.

Plant	Capacity	Stage	District
Upper Tamor Hydroelectric Project	285 MW	Under construction	Taplejung
Tamor-Mewa Hydroelectric Project	128 MW	Under construction	Taplejung
Ghunsa Khola Hydroelectric Project	78 MW	Under construction	Taplejung
Middle Mewa Hydropower Project	74 MW	Under construction	Taplejung
Middle Tamor Hydropower Project	73 MW	Operational	Taplejung
Simbuwa Khola Hydroelectric Project	70 MW	Under construction	Taplejung
Kabeli-A Hydroelectric Project	38 MW	Under construction	Panchthar
Tamor Khola-5 Hydroelectric Project	38 MW	Under construction	Taplejung
Upper (Mathillo) Kabeli Hydropower Project	28 MW	Under construction	Taplejung
Kabeli B1 Hydropower Station	25 MW	Operational	Panchthar
Kabeli-3 Hydroelectric Project	22 MW	Under construction	Taplejung
Super Kabeli Khola 'A' Hydropower Project	14 MW	Operational	Taplejung
Super Kabeli Hydroelectric Project	12 MW	Under construction	Taplejung

Explore all Nepal hydropower →

More in the Koshi system

Koshi (Sapta Koshi)

Nepal's largest river system — the 'Sapta Koshi', seven rivers in one — and the 'Sorrow of Bihar' for its floods

Arun

An 'antecedent' river older than the Himalaya it cuts through — and home to the 900 MW Arun-3

Tama Koshi (Tamakoshi)

The river behind Upper Tamakoshi — Nepal's single largest hydropower plant at 456 MW

Dudh Koshi

Everest's own river — the 'milk river' fed by Khumbu glaciers, and a major storage-project candidate

Sun Koshi

The Koshi's central trunk — a world-class rafting river and the Sun Koshi–Marin diversion

Common questions

Tamor: frequently asked questions

How long is the Tamor?+

The Tamor is about 192 km long.

Where does the Tamor start?+

The Tamor rises at The Kanchenjunga massif in Taplejung, far-eastern Nepal. It empties at Joins the Sun Koshi and Arun at Tribeni.

Which river system does the Tamor belong to?+

The Tamor is part of the Koshi river system. Snow- and glacier-fed, rising in the Greater Himalaya.

What are the main tributaries of the Tamor?+

Its main tributaries include Mewa, Maiwa, Kabeli.

What hydropower is built on the Tamor?+

13 catalogued hydropower plants are on or fed by the Tamor, totalling 883 MW. The largest is Upper Tamor Hydroelectric Project at 285 MW in Taplejung.

Sources & data note

River length and drainage figures are approximate. The mapped course is the real river centreline from OpenStreetMap, clipped to Nepal. Hydropower figures are from our own source-cited hydro database.