Location

Dibang Valley, Arunachal Pradesh

Installed Capacity

3,097 MW

Type of Project

Run of river hydroelectric project

River System

Dri & Tangon Rivers (tributaries of Dibang River)

Dam Type

Concrete gravity dams

Dam Heights

Dri: 101.5 metres; Tangon: 80 metres

Total Land Requirement

~1,150 hectares (mostly forest land)

Environmental Impact

Falls in Eastern Himalayas one of world biodiversity hotspots

Biodiversity Concerns

Home to rare species like Mishmi takin, clouded leopard, red panda

Indigenous Communities Affected

Primarily Idu Mishmi tribe

Executing Company

Etalin Hydro Electric Power Company Limited (JV of Jindal Power Ltd. & HPDCAPL)

Ownership

Jindal Power Ltd 74%, HPDCAPL (GoAP) 26%

Project Status

Fund allocation of ₹269.97 crore done in 2025 by GoAP; forest clearance re-evaluation ongoing

Ethnic Group

Idu-Mishmi (part of larger Mishmi tribal group)

Location

Dibang Valley, Lower Dibang Valley & parts of Lohit District in Arunachal Pradesh

Language

Idu-Mishmi (Tibeto-Burman family)

Population

Approx. 12,000 (Census 2011)

Key Livelihoods

Shifting cultivation (jhum), fishing, hunting, weaving

Religious Beliefs

Animism; strong belief in nature spirits & shamanism

Sacred Practices

Priests called ‘Igu’ mediate between humans & spirits

Social Structure

Clan-based, egalitarian society with customary laws

Conservation Role

Traditionally preserve forest patches as sacred groves

Conflict Concerns

Strong opposition to projects affecting sacred landscapes, biodiversity & displacement

Location

Northeastern Arunachal Pradesh bordering China (Tibet)

Geographic Features

Deep valleys, high mountain ridges, snow covered peaks

River Systems

Dibang River & its tributaries Dri, Ithun, Tangon, etc.

Forest Type

Tropical evergreen to alpine forests

Biodiversity Status

Eastern Himalayan biodiversity hotspot

Fauna

Snow leopard, Mishmi takin, red panda, hoolock gibbon

Tribal Population

Dominated by Idu-Mishmi & Miju-Mishmi tribes

Strategic Importance

Close to India-China LAC; under focus for infrastructure

Challenges

Development vs ecology conflicts, remoteness, seismic sensitivity

Tehri Dam

Uttarakhand

2,400

Bhagirathi

Storage

Sardar Sarovar

Gujarat

1,450

Narmada

Gravity dam

Subansiri Lower

Arunachal Pradesh (Under Construction)

2,000

Subansiri

Run-of-river

Nathpa Jhakri

Himachal Pradesh

1,500

Satluj

Run-of-river

Koyna Hydro Project

Maharashtra

1,960

Koyna

Storage

Bhakra Nangal

Himachal Pradesh/Punjab

1,325

Satluj

Gravity dam

Etalin HEP

Arunachal Pradesh

3,097 (Proposed)

Dri & Tangon (Dibang tributaries)

Run-of-river

Dibang Multipurpose Project

Arunachal Pradesh

2,880 (Under Clearance)

Dibang

Multipurpose

PRACTICE QUESTION

Q. Assess ecological impact of large scale hydropower projects in seismic & biodiversity-sensitive zones with reference to Etalin & Subansiri projects.