"Mega-dams on transboundary rivers are as much instruments of strategy as of development." Examine with reference to the Brahmaputra basin.

The Yarlung Tsangpo flows out of Tibet and becomes the Siang and then the Brahmaputra in India. Whoever builds dams upstream therefore shapes water, floods and livelihoods downstream. China has approved a mega-dam on the river's lower reaches, and India formally protested on 30 December 2024 [1]. India's response is the proposed Upper Siang project. Together they show that dams in this basin serve power and flood control, but they also serve geopolitics.

Development purpose

• Clean energy: Arunachal's steep valleys hold large hydropower potential. Upper Siang is listed among India's National Projects [2].
• Flood moderation: Upper Siang storage is officially expected to benefit flood-prone Assam [3].
• China's framing: Beijing calls its projects run-of-the-river projects that do not divert water [1].

Strategic purpose

• Upstream leverage: China controls the headwaters, and the two countries have no water-sharing treaty. China shares only flood-season data, under the 2006 Expert Level Mechanism (ELM) and later MoUs [1][4]. This feeds Indian fears of lean-season diversion or sudden releases.
• Counter-storage: India "carefully monitors" Brahmaputra developments to protect its interests [1]. Upper Siang storage is seen as a buffer against upstream shocks.
• Information as power: India and China agreed to an early ELM meeting on resuming hydrological data sharing [1]. Data is now used as a bargaining chip.
• Sovereignty signalling: Large dams in disputed border areas also assert a state's presence on the ground.

Where strategy undermines development

• Consent deficit: The NHRC took suo motu cognizance of Siang protests over displacement, livelihoods and ecology [5]. Pushing ahead at speed for strategic reasons erodes local trust.
• Seismic cascade risk: The eastern Himalaya is highly earthquake-prone. If an upstream dam fails, a full downstream reservoir could make the flood worse.
• Lower riparian: Bangladesh bears the combined effects of dams built by both India and China.

So in the Brahmaputra basin, mega-dams are as much tools of strategy as of development. Each can still weaken the other. The way forward is to:

• expand the ELM to cover year-round data and the operating rules of each dam;
• carry out basin-wide EIAs;
• secure tribal consent through the Social Impact Assessment required by the LARR Act, 2013.

A dam that local people accept and that is based on shared data serves both security and sustainable development, in line with SDG 6.5 on transboundary water cooperation.