Arunachal’s Upper Siang project: Debabrata Saikia seeks downstream impact assessment, writes to President

Guwahati: Senior Congress leader and former MLA Debabrata Saikia on Wednesday wrote to President Droupadi Murmu seeking protection of Assam’s downstream interests, public safety and ecological security in connection with the proposed Siang Upper Multipurpose Project (SUMP) in Arunachal Pradesh.

In his representation, Saikia said, “I respectfully submit this representation seeking Your Excellency’s intervention for safeguarding the long-term interests, lives, livelihoods and ecological security of the people of Assam in connection with the proposed Siang Upper Multipurpose Project / Upper Siang Multipurpose Storage Project (USMSP) in neighbouring Arunachal Pradesh.”

Saikia said river Siang, after flowing through Arunachal Pradesh, enters Assam and becomes part of the Brahmaputra river system. He said any large-scale intervention involving storage and regulation of its waters should be assessed from the perspective of the entire downstream river basin, particularly Assam.

Government records have described the Upper Siang project as being at the PFR stage, with proposed live storage of approximately 9.2 billion cubic metres (BCM) and flood moderation among its stated objectives. NHPC has also stated that the Ministry of Jal Shakti entrusted it with preparing the PFR for the Upper Siang Multipurpose Storage Project. NHPC issued tenders in July 2026 for exploratory drilling at the proposed Parong and Uggeng dam axes.

Saikia said a project involving storage and regulation of water on such a scale requires scientific, environmental, seismic and disaster-safety scrutiny, particularly from the perspective of downstream Assam.

He pointed to Assam’s recurring floods, riverbank erosion, siltation, destruction of agricultural land, damage to infrastructure, displacement and loss of livelihoods. He said recent disasters had again demonstrated the vulnerability of riverine communities.

While the project may have flood moderation among its objectives, Saikia said Assam should have access to studies examining how reservoir operation, sediment trapping and release, extreme rainfall, landslides, earthquakes, exceptional inflows, emergency releases and hypothetical dam-failure scenarios could affect downstream areas.

He said the issue should not be reduced to a debate over being “for” or “against” hydropower. The central question, according to Saikia, is whether a project of such scale affecting a major tributary of the Brahmaputra could proceed without Assam and its downstream population being fully informed, scientifically assessed, consulted and protected.

Saikia sought a comprehensive, independently reviewed downstream impact assessment covering river discharge, flood peaks, sediment transport, erosion and deposition, river morphology, wetlands, fisheries, agriculture, drinking-water sources, navigation, biodiversity and livelihoods in Assam.

He also called for detailed dam-break and extreme-event modelling, including maps identifying potentially affected areas in Assam. He said the assessment should cover extreme precipitation, landslide-induced waves, seismic events, cascading infrastructure failures and emergency reservoir releases.

On seismic and geological safety, Saikia called for independent scrutiny by recognised experts in seismology, geology, geotechnical engineering and dam safety. He also sought examination of reservoir-induced seismicity and the possible interaction between earthquakes, landslides and reservoir conditions.

He sought a long-term sediment-budget and river-morphology study, citing the high sediment load carried by the Brahmaputra system. Such a study, he said, should examine possible implications for Assam’s river channels, chars, riverbanks, wetlands and agricultural floodplains.

Saikia also called for a cumulative basin-level assessment covering major existing, under-construction and proposed projects in the wider Siang–Brahmaputra basin and their combined implications for Assam.

On Assam’s participation, he sought clarity on whether the state government had been formally consulted, submitted observations on downstream consequences, issued any consent, concurrence, NOC or other communication, or commissioned an independent technical assessment.

He called for all relevant correspondence and technical submissions, except legitimately protected information, to be placed in the public domain.

Saikia also sought meaningful participation of downstream communities, including representatives of potentially affected districts of Assam, experts from academic and technical institutions, fishermen, farmers, riverine communities and civil-society organisations.

He proposed a legally and institutionally defined mechanism for real-time sharing with Assam of rainfall, upstream discharge, reservoir levels, inflow, outflow and proposed releases. He also called for automatic warning systems extending from the project area to vulnerable downstream districts in Assam, with clearly defined warning times, communication protocols and evacuation responsibilities.

Saikia further proposed an independent multidisciplinary expert body involving hydrologists, river scientists, geologists, seismologists, dam-safety engineers, disaster-management specialists, ecologists and representatives or experts from both Arunachal Pradesh and Assam.

In his representation, Saikia requested the President to seek comprehensive reports from the governments of Assam and Arunachal Pradesh on the proposed project and its potential implications for Assam.

He also sought clarity on whether the Assam government had issued any consent, concurrence, NOC, approval, recommendation or other communication relating to the project and called for the relevant position to be placed before the people of Assam.

Saikia requested that the state government commission an independent Assam-specific downstream impact assessment rather than relying exclusively on studies commissioned by the project proponent.

He also urged that the matter be taken up, as considered appropriate, with the Government of India, Ministry of Jal Shakti, Ministry of Environment, Forest and Climate Change, Central Water Commission, National Dam Safety Authority, National Disaster Management Authority and other competent authorities.

He sought that no irreversible project activity or final statutory decision be undertaken without completion and appropriate scrutiny of environmental, geological, seismic, dam-safety, cumulative and downstream-impact studies required under applicable law.

Saikia also called for a comprehensive Dam-Break and Emergency Action Plan covering downstream Assam, supported by district-wise inundation mapping and evacuation planning.

He sought institutional arrangements for real-time hydrological information, warning of releases and emergency communication with Assam, besides meaningful consultation with the Assam government and potentially affected downstream communities.

He also proposed an independent expert consultation in Assam involving scientific institutions, universities, technical experts, stakeholder communities and other stakeholders.

Saikia requested the Assam and Arunachal Pradesh governments to prepare and publish a White Paper on the likely benefits, risks and safeguards for Assam arising from major upstream hydropower and storage projects in the Siang–Brahmaputra basin, including the proposed Upper Siang project.

Clarifying his position, Saikia said, “I wish to respectfully clarify that this representation should not be interpreted as opposition to development, renewable energy, or infrastructure in Arunachal Pradesh. Nor would it be appropriate, before completion of scientific studies, to presume either that the project will necessarily cause downstream disaster or that its proposed flood-moderation function will necessarily eliminate downstream risk.”

“My submission is much simpler: where the consequences of a project may extend across state boundaries and affect a river system upon which millions depend, scientific scrutiny, transparency, consultation, disaster preparedness and protection of downstream communities must precede irreversible decisions,” he said.

“The Brahmaputra is Assam’s lifeline. Its tributaries sustain our agriculture, fisheries, wetlands, biodiversity, culture, and civilisation. Decisions capable of materially altering this river system will have consequences extending far beyond the lifetime of any government,” Saikia said.

As a former Leader of the Opposition in the Assam Legislative Assembly and a former three-term MLA from Nazira, Saikia said he considered it his public responsibility to place the concerns before the President at a stage when preventive safeguards could still be examined and incorporated.

He requested President Murmu to treat the matter as one concerning the long-term safety and ecological security of Assam, seek the necessary reports from both state governments and take up Assam’s downstream concerns with the competent authorities of the Government of India.

“Protecting Assam need not mean opposing development elsewhere. It means ensuring that development proceeds on the foundation of science, transparency, constitutional federalism, environmental responsibility, and the safety of people living downstream,” Saikia added.