When Bangladesh and India signed the Ganga Water Sharing Treaty in December 1996, it was hailed as a diplomatic breakthrough. After decades of disputes surrounding the Farakka Barrage, the agreement replaced uncertainty with a rules-based framework for sharing the dry-season flow of the Ganga river.

For nearly thirty years, the treaty has stood as one of South Asia's most successful examples of hydro-diplomacy, demonstrating that even politically sensitive issues can be managed through negotiation rather than confrontation.

Yet as the treaty reaches the end of its thirty-year term in December 2026, simply extending it would ignore the profound environmental and geopolitical changes that have transformed the basin. The Ganges Treaty needs more than renewal—it needs reinvention.

The 1996 treaty was negotiated in a different era. Climate change was not yet central to policymaking, data-sharing technologies were limited, and the concept of integrated river basin management was still emerging.

The agreement focused primarily on dividing dry-season flows at Farakka between January and May. Under its formula, if the flow is below 70,000 cusecs, both countries receive an equal share. Between 70,000 and 75,000 cusecs, Bangladesh receives 35,000 cusecs; above 75,000 cusecs, India receives 40,000 cusecs, with Bangladesh receiving the remainder.

Although this arrangement reduced bilateral tensions, it was designed around historical hydrological patterns rather than an uncertain climatic future.

Climate Change Has Changed the Basin

Today, that future has arrived.

The Ganga Basin spans more than one million square kilometres and supports approximately 650 million people, making it one of the world's largest transboundary river basins. Nearly half of India's population lives within the basin, while the Ganges—known as the Padma after entering Bangladesh—remains indispensable for agriculture, fisheries, navigation, drinking water, and ecosystem health.

Bangladesh alone receives water from 54 transboundary rivers originating in India, making cooperative water governance a strategic necessity rather than a diplomatic luxury.

Climate change has fundamentally altered the assumptions on which the treaty rests. According to the Intergovernmental Panel on Climate Change (IPCC), South Asia is expected to experience more frequent extreme rainfall, prolonged droughts, glacier retreat, and rising temperatures.

Himalayan glaciers—the source of much of the Ganga's flow—are melting at unprecedented rates, while changing monsoon patterns are increasing hydrological uncertainty. Instead of predictable seasonal flows, both Bangladesh and India must now prepare for greater variability, alternating between devastating monsoon floods and severe dry-season water shortages.

Shared Challenges, Different Realities

For Bangladesh, the consequences are particularly severe. Reduced freshwater flow allows seawater to penetrate further inland, increasing salinity across the southwest. Millions of people in coastal districts are directly affected through declining agricultural yields, shortages of safe drinking water, and damage to freshwater fisheries.

Lower river discharge also threatens the Sundarbans, the world's largest mangrove forest, by altering its delicate freshwater-saltwater balance. Meanwhile, reduced navigability, increased sedimentation, and riverbank erosion impose significant economic costs.

Water scarcity, therefore, extends far beyond environmental concerns; it directly affects food security, public health, livelihoods, and national resilience.

India, too, faces mounting water pressures. Rapid urbanization, expanding irrigation, industrial demand, and groundwater depletion have intensified competition over freshwater resources.

The Ganges Basin contributes substantially to India's agricultural production, supporting millions of farmers and numerous major cities. Consequently, Indian policymakers must balance domestic development needs with international commitments.

This reality underscores why future negotiations should not be framed as a zero-sum contest. Both countries are confronting the same climate-driven crisis from different positions along the river.

Beyond Water Allocation

The greatest weakness of the existing treaty is its narrow focus on water allocation. Modern water governance recognizes that rivers are ecosystems rather than pipelines.

A sustainable agreement should address water quality, environmental flows, groundwater recharge, sediment management, biodiversity conservation, flood forecasting, and climate adaptation alongside water sharing. Simply negotiating over cubic feet per second without considering the health of the river itself is no longer sufficient.

International experience offers valuable lessons. The Mekong River Commission has demonstrated the importance of joint scientific monitoring and data exchange among riparian states. Similarly, the Senegal River Basin Development Organization has shown how shared management of infrastructure can generate mutual economic benefits.

While South Asia's political dynamics differ, these examples illustrate that durable cooperation depends on flexible institutions that can adapt to changing environmental conditions.

Five Priorities for a Renewed Treaty

A renewed Ganga Water Treaty should therefore incorporate five key reforms.

First, water allocation should become adaptive rather than static. Instead of relying solely on fixed thresholds, the agreement should include climate-responsive mechanisms that adjust sharing arrangements according to real-time hydrological conditions.

Second, Bangladesh and India should establish a transparent, real-time data-sharing platform covering river flows, rainfall, groundwater, and sediment transport. Reliable information reduces political mistrust and enables evidence-based decision-making.

Third, environmental flows should receive explicit legal protection. Maintaining minimum ecological flows is essential for sustaining fisheries, wetlands, biodiversity, and the Sundarbans. A river that loses its ecological integrity ultimately fails both countries.

Fourth, the Joint Rivers Commission, established in 1972, should be strengthened into a permanent scientific and technical institution with greater authority to monitor implementation, coordinate climate adaptation projects, and resolve disputes before they escalate politically.

Finally, negotiations should gradually evolve toward basin-wide cooperation involving Nepal. Improved upstream storage, watershed conservation, and coordinated river management could enhance dry-season flows while reducing flood risks across the basin. Climate resilience requires cooperation that extends beyond bilateral water allocation.

A Treaty for the Twenty-First Century

The upcoming negotiations will therefore test not only Bangladesh-India relations but also South Asia's capacity to adapt its institutions to a changing climate.

Over the past decade, the two countries have deepened cooperation in trade, connectivity, energy, and security. Modernizing the Ganges Treaty offers an opportunity to reinforce that broader partnership by demonstrating that shared challenges can produce shared solutions.

Ultimately, rivers cannot be governed through twentieth-century thinking in a twenty-first-century climate. The Ganga is more than a shared watercourse; it is the ecological, economic, and cultural lifeline of hundreds of millions of people.

The treaty that once symbolized diplomatic success should now become a model for climate-resilient hydro-diplomacy. The river has changed, the climate has changed, and the needs of both nations have changed. The treaty must change with them.

(The author is an undergraduate student at the Department of International Relations, Jahangirnagar University, Dhaka, Bangladesh. Views expressed are personal. She can be reached at jannatorin29@gmail.com. )