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Lower Subansiri Hydroelectric Power Project, India


The 2000 MW Lower Subansiri hydroelectric power Project, proposed to come up at Gerukamukh of Assam Arunachal border is the first large hydroelectric project to be constructed in the Subansiri river basin.

The Lower Subansiri hydroelectric power project (LHSEP) is the part of an ambitious plan of government of Indian to generate 50,000MW. The program was initiated in May 2003. The Central Electricity Authority (CEA) has taken up pre-feasibility studies of 162 projects as part of this initiative, among which a total 5,600MW was planned on Subansiri River.

The LHSEP is designed as a run-of-the river power project on the lower reach of Subansiri River, a tributary of River Brahmaputra. River Subansiri flows from Arunachal Pradesh into Assam where it joins the Brahmaputra.

The Subansiri hydropower project has three components, namely the 2,000MW Upper Subansiri, the 1,600MW Middle Subansiri, and the 2,000MW Lower Subansiri. The Lower Subansari HEP received clearance from the government in August 2003, following which NHPC started developing the project.

The Northeast of India has been identified as India’s ‘future powerhouse’ [1]. In 2001, the Central Electricity Authority CEA), India has identified 168 large hydroelectric projects with a potential of 63,328 MW in the Brahmaputra river basin [2]. This includes 22 projects having potential of 15,191 MW in the Subansiri river basin. The 2000 MW Lower Subansiri Hydroelectric Power Project, proposed to come up at Gerukamukh, Assam pose a real threat to the freshwater biodiversity of the downstream of Subansiri river basin by the regulation of the river through diversion, impoundment and reducing water discharge to the downstream [3].

The construction of Lower Subansiri started in 2005 and was due to be completed in 2010. However, the project has been delayed because of strong opposition over its potential environmental impact. It is alleged that the dam is located in a seismic zone but it is significantly under-designed to resist earthquakes. The fluctuation of water level in the river is also feared to affect the ecology in the lower Subansiri region in future.

The project has displaced many families, but it is claimed that it will displace many more people residing downstream of the project because of ecological changes endangered by the project. The project is also alleged to affect cultivation and cattle graze in the downstream area. In December 2012, NHPC set up an independent dam design review panel to facilitate the progress of the project while taking into account the issues advanced against the dam from different quarters [4] There is also strong opposition from Assam. As Assam is located on the downstream of the project, protesters have been arguing that the state will bear the brunt of environmental impact. They are also concerned over the safety of the dam as the project is located in a seismic zone [5].

Basic Data

Name of conflict:Lower Subansiri Hydroelectric Power Project, India
State or province:Assam
Location of conflict:Gerukamukh
Accuracy of locationHIGH (Local level)

Source of Conflict

Type of conflict. 1st level:Water Management
Type of conflict. 2nd level:Dams and water distribution conflicts
Specific commodities:Electricity

Project Details and Actors

Project details

The Lower Subansiri hydroelectric power project (LHSEP) is the part of an ambitious plan of government of Indian to generate 50,000MW.

The Subansiri hydropower project has three components, namely the 2,000MW Upper Subansiri, the 1,600MW Middle Subansiri, and the 2,000MW Lower Subansiri.

The cost of Lower Subansiri project was originally estimated to be INR62.85bn ($1.16bn) at 2002 price level but has since been revised to INR106.6bn ($1.97bn) at 2010 price level. The project cost is expected to further go up because of the delay.

The project cost is being met through 70% equity and 30% debt financing by the provision of a term loan. The central government is providing budgetary support as part of the equity component.

The LHSEP consists of a concrete gravity dam, which will be 116m high from the river bed level and 130m from foundation. The length of the dam will be 284m. The gross storage capacity of the reservoir will be 1.37km3.

The power house will be equipped with eight 250MW Francis turbines located on surface on the left bank of the river. It will also have eight horse shoe shaped head race tunnels (diameter 9.5m and length varying from 608m to 1,168m), eight horse shoe shaped surge tunnels (diameter 9.5m and length varying from 400m to 485m) and eight circular penstocks (diameter varying between 400m and 485m, and length between 7m and 9.5m). A tail race channel (35m long and 206m wide) will take the water discharged by the turbines back to the river [4].

Level of Investment for the conflictive project1.970,000,000
Type of populationRural
Start of the conflict:2003
Company names or state enterprises:National Hydroelectric Power Corporation of India (NHPC) from India
Central Electricity Authority (CEA) from India
Relevant government actors:Assam Government, Ministry of Environment & Forest , Government of India, Assam Pollution Control Board
Environmental justice organizations (and other supporters) and their websites, if available:Peoples Movement for Subansiri Brahmaputra Valley [PMSBV], River Basin Friends, All Assam Students Union [AASU], The Krishak Mukti Sangram Samity [KMSS], The Assam Jatiyatabadi Yuva Chatra Parishad [AJYCP], Takam Mising Porin Kebang [TMPK], Kalpavriksh Environmental Action Group (India), International Rivers (US)

Conflict & Mobilization

IntensityHIGH (widespread, mass mobilization, violence, arrests, etc...)
Reaction stagePREVENTIVE resistance (precautionary phase)
Groups mobilizing:Farmers
Indigenous groups or traditional communities
Local ejos
Landless peasants
Local government/political parties
Social movements
Local scientists/professionals
Forms of mobilization:Blockades
Boycotts of official procedures/non-participation in official processes
Development of a network/collective action
Development of alternative proposals
Lawsuits, court cases, judicial activism
Media based activism/alternative media
Objections to the EIA
Official complaint letters and petitions
Public campaigns
Street protest/marches
Hunger strikes and self immolation


Environmental ImpactsPotential: Biodiversity loss (wildlife, agro-diversity), Floods (river, coastal, mudflow), Food insecurity (crop damage), Loss of landscape/aesthetic degradation, Soil erosion, Deforestation and loss of vegetation cover, Groundwater pollution or depletion, Large-scale disturbance of hydro and geological systems, Reduced ecological / hydrological connectivity
Socio-economical ImpactsPotential: Displacement, Loss of livelihood, Loss of traditional knowledge/practices/cultures, Violations of human rights, Land dispossession, Loss of landscape/sense of place


Project StatusProposed (exploration phase)
Conflict outcome / response:Compensation
Institutional changes
New legislation
Strengthening of participation
Technical solutions to improve resource supply/quality/distribution
Under negotiation
Violent targeting of activists
New Environmental Impact Assessment/Study
Proposal and development of alternatives:1. There must be a serious and long term investigation of the geological framework, hydrological features of the Brahmaputra basin
2. The question of downstream impacts along the river Brahmaputra must be recognized. Downstream impact assessments must be a pre-condition for all dam proposals.
3. There must be a cumulative impact assessments of all upstream dams in Arunachal Pradesh before clearance is given to construction of dams there.
4. The rights of the people of Assam over these water resources must be recognized by the Government of India
5. immediate tripartite discussion with the Prime Minister of India, Government of Assam and Representative of downstream people of Assam who are agitating against the construction of Lower Subansiri Hydro Power Project.
6. Till all such issues are resolved, KMSS demands a moratorium on construction work of LSHP and other hydro power projects of the Brahmaputra basin [7]
Do you consider this an environmental justice success? Was environmental justice served?:Not Sure
Briefly explain:Chief minister Tarun Gogoi said the Union power ministry has approved the seismic safety recommendations for NHPCs Lower Subansiri hydro-electric project and has appealed to anti-dam agitators to withdraw their protest to pave the way for construction of the dam [5].
Union Minister Jairam Ramesh suggested that work on the Subansiri Lower Hydroelectric Power Project is unlikely to be halted. He promised to address the concerns of the downstream States [6]

Sources & Materials

Juridical relevant texts related to the conflict (laws, legislations, EIAs, etc)

Dams, Displacement, Policy and Law in India

References to published books, academic articles, movies or published documentaries

impacts of large dam: a case study from India

Lower Subansiri Hydroelectric Power Project and future of the Subansiri River Ecosystem

The Subansiri Subversion

Erosion and devastation of river Subansiri and future downstream


Register of Large Dams 2009.pdf


Lower Subansiri hydel project: Stop all work till critical issues are resolve

[1] North East Dams

[2] A flood of dams

[3] Lower Subansiri Hydroelectric Power Project and future of the Subansiri River Ecosystem by Ranjit Dutta* and Sarada Kanta Sarma

[4] Lower Subansiri Hydroelectric Power Project, India

[5] Gogoi calls for end to anti-Subansiri dam stir

[6] Subansiri dam work not to be halted: Ramesh

[7] Demand for a moratorium on construction work of Lower Subansiri Hydro Power (LSHP) -

NHPC bid to end Subansiri dam impasse

Arunachal had warned NHPC on dam project

Anti–big dam groups fire betrayal salvo at NHPC

Anti-dam protest gets violent again

Assam: Medha Patkar leads protests against mega dams

Mega Dams In North-East India: Are They Necessary?

Subansiri Dam construction will not stop : Ramesh

Mega dams: campaigning against the plans of the Indian government

Activists Flay Subansiri Power Project

Related media links to videos, campaigns, social network

Assam: Protests hit Subansiri hydro-power project

Subansiri Lower Project

Lower Subansiri Hydroelectric Project - dam site

Subansiri Dam title

Stop Big Dam in lower subansiri hydroelectric project

Meta information

Contributor:Swapan Kumar Patra
Last update18/08/2019
Conflict ID:942