Expert panel backs green clearance for the Subansiri Upper hydro project
Can Arunachal's big dams be built without paying too high a price in forests?
Published 26 September 2026. Written by Pratidin from the reports linked at the end; every fact checked by a separate review before publishing. How we work
The Union Environment Ministry's Expert Appraisal Committee (EAC) has recommended environmental clearance for NHPC's 1,605 MW Subansiri Upper hydroelectric project in Arunachal Pradesh, the Indian Express reported. The recommendation is conditional. Final clearance depends on the project getting forest clearance for about 2,733 hectares of forest land, and NHPC must prepare a site-specific, time-bound Ecosystem Restoration and Biodiversity Management Plan. The EAC flagged that the impact would go beyond forest loss, affecting biodiversity, habitat continuity, wildlife movement and ecosystem services.
The project, near Menga about 20 km from Daporijo in Upper Subansiri district, involves a 237-metre-high dam and a reservoir of about 22.2 sq km, and is meant for both power generation and flood moderation. About 1.35 lakh trees would be felled and around 1,139 households are likely to be affected by land acquisition. Compensatory afforestation is proposed on 5,466 hectares of degraded forest land at 144 sites across 14 districts of Madhya Pradesh, far from the Himalayan forest being lost.
The Subansiri is a major tributary of the Brahmaputra. Downstream, NHPC's 2,000 MW Subansiri Lower project, whose construction was stalled by protests from 2011 over dam safety and downstream impact, is being commissioned in phases. The EAC noted a 2009 Supreme Court direction that any proposal on the upper stream of the Subansiri would be considered independently on its own merit. The case revives old questions about distant afforestation and the cumulative impact of several dams on one river.
Prelims facts
- Environmental clearance is granted under the EIA Notification, 2006, issued under the Environment (Protection) Act, 1986; Category A projects are appraised by sectoral Expert Appraisal Committees of the Union Environment Ministry.
- Diversion of forest land for non-forest use needs separate approval under the Forest (Conservation) Act, 1980, renamed the Van (Sanrakshan Evam Samvardhan) Adhiniyam, 1980 in 2023.
- Money collected for compensatory afforestation is managed under the Compensatory Afforestation Fund Act, 2016, through CAMPA.
Quick recall
- What is the capacity of the Subansiri Upper project?
- 1,605 MW.
- Which company is developing Subansiri Upper?
- NHPC.
- How much forest land does the project need?
- About 2,733 hectares.
- How high is the proposed dam?
- About 237 metres.
- Where is compensatory afforestation proposed?
- On 5,466 hectares of degraded forest land at 144 sites in 14 districts of Madhya Pradesh.
- Under which instrument are environmental clearances granted?
- The EIA Notification, 2006, under the Environment (Protection) Act, 1986.
- What did the Supreme Court direct in 2009 about the upper Subansiri?
- That any proposal on the upper stream would be considered independently on its own merit.
- What is the capacity of the Subansiri Lower project?
- 2,000 MW.
Prelims practice question
Consider the following statements:
1. Environmental clearance and forest clearance for a project are granted under the same law.
2. A recommendation by an Expert Appraisal Committee is by itself the final environmental clearance.
Which of the statements given above is/are correct?
- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Show answer
Answer: (d) Neither 1 nor 2. Environmental clearance flows from the EIA Notification, 2006 under the Environment (Protection) Act, 1986, while forest clearance is under the Forest (Conservation) Act, 1980. The EAC only recommends; the Ministry grants clearance.
Use this in UPSC Mains: previous-year questions
Recurring theme: Environmental clearance and the costs of big dams
- How to use this
Use it to conclude that dam safety and downstream risk must be built into clearance of new large dams, especially in seismic Himalayan basins.
- NHPC's 1,605 MW Subansiri Upper project involves a 237-metre dam in a young, earthquake-prone mountain range, upstream of Assam on a major Brahmaputra tributary.
- Downstream, construction of the 2,000 MW Subansiri Lower was stalled by protests from 2011 over dam safety and downstream impact; an independent review under the Dam Safety Act, 2021 is suggested.
- How to use this
Use the Subansiri Upper appraisal as a live example of how the EIA Notification, 2006 works in practice, and of the gaps any revision should address.
- Category A projects are appraised by the Environment Ministry's sectoral Expert Appraisal Committees; the EAC recommended conditional EC for the 1,605 MW project, subject to forest clearance for about 2,733 hectares.
- Forest diversion needs separate approval under the Forest (Conservation) Act, 1980 (renamed Van (Sanrakshan Evam Samvardhan) Adhiniyam in 2023); compensatory afforestation is proposed on 5,466 hectares in Madhya Pradesh.
- Gap: project-by-project appraisal misses cumulative impact of several dams on one river; basin-wide studies are suggested, and a 2009 Supreme Court direction requires upstream proposals to be considered on merit.
Mains practice question
Large hydropower projects in the Eastern Himalaya promise clean energy and flood moderation but carry heavy ecological and social costs. Discuss with reference to the Subansiri basin, and suggest how the clearance process can be improved. (250 words)
Model answer
The Expert Appraisal Committee's recommendation of environmental clearance for the 1,605 MW Subansiri Upper project in Arunachal Pradesh, subject to forest clearance for about 2,733 hectares, captures the dilemma of Himalayan hydropower.
Benefits
- Clean, firm power: storage hydro supports grid balancing as solar and wind grow.
- Flood moderation: the project's reservoir is meant to moderate floods, a recurring problem in the Brahmaputra valley.
- Regional development: roads, jobs and revenue for a remote district.
- Strategic presence in a sensitive frontier State.
Costs
- Forest loss: about 1.35 lakh trees; the EAC itself warned of effects on habitat continuity and wildlife movement.
- Displacement: around 1,139 households may be affected by land acquisition.
- Distant offsets: compensatory afforestation on degraded land in Madhya Pradesh cannot replace Himalayan forest.
- Safety and seismicity: a 237-metre dam in a young, earthquake-prone mountain range; protests stalled Subansiri Lower from 2011.
- Cumulative impact: several projects on one river change flows and sediment downstream in Assam.
Improving the process
- Mandatory basin-wide cumulative impact and carrying capacity studies before individual clearances, in line with the Supreme Court's 2009 direction to examine upstream proposals on merit.
- Environmental flows and sediment management written into clearance conditions.
- Afforestation in the same landscape wherever possible, with independent monitoring of CAMPA spending.
- Free, prior and informed consent of affected communities and fair rehabilitation.
- Independent dam safety review under the Dam Safety Act, 2021.
Conclusion
Hydropower can serve India's energy transition, but only if appraisal looks at whole river basins and restores what is lost close to where it is lost.
The basics
Why this matters
Arunachal Pradesh has some of India's largest untapped hydropower potential and some of its richest forests. Every big dam there forces a trade-off between clean energy, flood control and development on one side, and forests, wildlife and local communities on the other. The Subansiri Upper recommendation shows how India's clearance system handles that trade-off, and where it is criticised. It is a strong case study for GS3 environment and infrastructure answers.
How a project gets cleared
Large projects need two separate approvals. Environmental clearance comes under the EIA Notification, 2006: the developer studies impacts, holds a public hearing, and a sectoral Expert Appraisal Committee examines the proposal and recommends a decision. Forest clearance, for using forest land, comes under a different law and happens in two stages. In this case, the EAC has made environmental clearance conditional on forest clearance.
- 1EIA studyDeveloper assesses impacts under agreed terms of reference
- 2Public hearingAffected people give their views
- 3EAC appraisalExpert committee recommends clearance with conditions
- 4Forest clearanceSeparate approval to divert forest land
- 5Final clearanceMinistry issues environmental clearance
Weighing land lost and land planted
Compensatory afforestation is meant to make up for forest loss. When non-forest land is not available, degraded forest land of twice the area is used, which is why 2,733 hectares lost are matched by 5,466 hectares to be planted. But the planting is in Madhya Pradesh, far from the Eastern Himalaya. Critics say a young plantation in central India cannot replace an old Himalayan forest and its wildlife corridors.
Upper and Lower Subansiri
The Subansiri already hosts one giant project. Subansiri Lower, a 2,000 MW run-of-the-river project on the Assam-Arunachal border, was stalled for years after protests from 2011 over dam safety and downstream effects in Assam. The Supreme Court directed in 2009 that any upstream proposal be judged on its own merits. The Upper project has a 237-metre dam with a reservoir of about 22.2 sq km.
- 2,000 MW
- Run-of-the-river, eight 250 MW units
- Contract awarded in 2003
- Stalled by protests from 2011; commissioning in phases
- 1,605 MW
- 237-metre dam, 22.2 sq km reservoir
- Power plus flood moderation
- EAC recommended clearance in 2026
What better appraisal would look like
Experts argue that dams on the same river should be judged together, through basin-level cumulative impact studies, rather than one by one. They also call for environmental flows so that rivers do not run dry below dams, restoration close to the damaged landscape, and genuine consent from local communities. The EAC's demand for a restoration and biodiversity plan is a step, but its value depends on enforcement.
You now know
- The EAC recommended environmental clearance for NHPC's 1,605 MW Subansiri Upper project in Arunachal.
- It needs about 2,733 ha of forest land and would fell about 1.35 lakh trees.
- Compensatory afforestation: 5,466 ha of degraded land in 14 districts of Madhya Pradesh.
- The Subansiri is a major tributary of the Brahmaputra; Subansiri Lower (2,000 MW) lies downstream.
Go deeper
In one line: An expert panel has recommended green clearance for a 1,605 MW dam in Arunachal Pradesh, on condition that it also gets forest clearance and restores biodiversity.
Why it matters for UPSC
It is a textbook case for GS3 environment (EIA, forest diversion, afforestation) and infrastructure (hydropower, energy security). Prelims can test the laws and bodies involved.
The core idea
Big projects need an appraisal by an Expert Appraisal Committee under the EIA Notification, 2006, and separate Forest Clearance for using forest land. Lost forest is to be made up through Compensatory Afforestation, here planned far away in Madhya Pradesh. The Subansiri River already has a 2,000 MW project downstream, which raises the question of cumulative impact on the Brahmaputra system.
Numbers and dates to remember
- 1,605 MW; 237-metre dam; about 22.2 sq km reservoir.
- 2,733 ha forest land; 1.35 lakh trees; about 1,139 households.
- 5,466 ha afforestation at 144 sites in 14 MP districts.
- 2009: Supreme Court direction on upstream proposals.
Where to go next
- Expert Appraisal Committee: The panel that screens big projects
- Forest Clearance: Permission to use forest land
- Compensatory Afforestation: Planting trees to make up for those cut
- Subansiri River: A Himalayan tributary of the Brahmaputra
Go deeper: why Himalayan hydropower is contested
The Eastern Himalaya is attractive for hydropower because rivers fall steeply through narrow valleys. Storage projects can also store monsoon water and moderate floods downstream in Assam. That is the case made for Subansiri Upper.
The concerns are equally strong. The region is seismically active and geologically young. Big reservoirs submerge forests and farmland and displace people. Downstream communities fear sudden releases and changes in fish, sediment and flood patterns. On the Subansiri River, these fears already stalled Subansiri Lower for years after 2011.
The clearance system addresses these risks project by project. The Expert Appraisal Committee can impose conditions, such as a biodiversity management plan, and Forest Clearance requires Compensatory Afforestation. But critics point to gaps: basin-level cumulative impact studies are not always done before individual clearances, afforestation often happens far away, and compliance monitoring is weak.
For Mains, balance the energy and flood-control case against ecological and social costs, then suggest reforms: basin-wide assessments, environmental flows, local restoration, consent of affected communities and independent dam safety review.
Where to go next
- Expert Appraisal Committee: The panel that screens big projects
- Forest Clearance: Permission to use forest land
- Compensatory Afforestation: Planting trees to make up for those cut
- Subansiri River: A Himalayan tributary of the Brahmaputra
Expert Appraisal Committee
The panel that screens big projects
In one line: An Expert Appraisal Committee is a group of specialists who check whether a big project is safe for the environment.
What it does
It reads the project's impact study, looks at the public hearing and asks questions. Then it recommends approval, rejection or approval with conditions.
Who decides
The committee only advises. The Environment Ministry gives the final clearance. Committees are set up for different sectors, so one looks at river valley and hydropower projects, another at mines, and so on.
Where to go next
- Forest Clearance: Permission to use forest land
- Compensatory Afforestation: Planting trees to make up for those cut
Forest Clearance
Permission to use forest land
In one line: Forest clearance is permission from the government to use forest land for something else, like a dam or road.
The law behind it
It comes under the Forest (Conservation) Act, 1980, now called the Van (Sanrakshan Evam Samvardhan) Adhiniyam, 1980.
How it works
It usually comes in two stages. First approval in principle, then final approval after conditions such as paying for new forests are met. It is separate from environmental clearance, so a project needs both.
Where to go next
- Expert Appraisal Committee: The panel that screens big projects
- Compensatory Afforestation: Planting trees to make up for those cut
Compensatory Afforestation
Planting trees to make up for those cut
In one line: When forest is cut for a project, the builder must pay for new trees to be planted elsewhere.
How much land
Usually an equal area of non-forest land, or double the area of degraded forest land if non-forest land is not available.
The criticism
New plantations far away, like in Madhya Pradesh for a project in Arunachal, cannot replace an old, rich forest and the animals that live there. The money for new forests is managed through a fund called CAMPA.
Where to go next
- Expert Appraisal Committee: The panel that screens big projects
- Forest Clearance: Permission to use forest land
Subansiri River
A Himalayan tributary of the Brahmaputra
In one line: The Subansiri is a Himalayan river that flows through Arunachal Pradesh into Assam and joins the Brahmaputra.
Why it is important
It brings a large volume of water and has big hydropower potential. Its floods also affect farms and towns in Assam, which is why people downstream watch every dam built on it.
Dams on it
The 2,000 MW Subansiri Lower project is near the Assam border, and the 1,605 MW Subansiri Upper project is planned further upstream in Upper Subansiri district.
Where to go next
- Expert Appraisal Committee: The panel that screens big projects
- Forest Clearance: Permission to use forest land
Take the 26 September 2026 quiz: 30 Prelims-style questions with answers