With the landmark 1996 India-Bangladesh pact set to expire in December, climate stress, upstream diversions and competing demands threaten dry-season flows for millions downstream.

The clock is ticking as the 30-year Ganges Water Sharing Treaty between India and Bangladesh approaches its expiry on 12 December 2026. Without a timely renewal or successor agreement, dry-season water security for tens of millions in Bangladesh hangs in the balance, while Indian states such as Bihar and West Bengal press their own claims.

Signed on 12 December 1996 by then Indian Prime Minister HD Deve Gowda and Bangladeshi Prime Minister Sheikh Hasina, the treaty ended decades of acrimony that began with the construction of the Farakka Barrage in West Bengal. Completed in the mid-1970s, the barrage was designed to divert water into the Hooghly River to maintain navigability at Kolkata Port. Downstream, Bangladesh experienced reduced flows, ecological damage, siltation and hardship for farmers and fishermen during the lean season from January to May.

Farakka’s Legacy and the 1996 Formula

The 1996 agreement institutionalised a 10-day sharing formula based on historical flow data from 1949 to 1988 measured at Farakka. When availability falls to 70,000 cusecs or less, the two countries share equally. Between 70,000 and 75,000 cusecs, Bangladesh is guaranteed 35,000 cusecs and India takes the balance. Above 75,000 cusecs, India receives a fixed 40,000 cusecs and Bangladesh the remainder. Alternate three 10-day periods in the critical March-May window also provide each side a guaranteed 35,000 cusecs.

A Joint Committee under the Joint Rivers Commission monitors implementation. Yet the treaty has never been free of friction. Bangladesh has repeatedly reported shortfalls at Hardinge Bridge, particularly in the driest months. Studies in Bangladesh covering 1997-2016 found that the country received less than its stipulated share in a significant number of critical periods. The absence of a firm minimum-guarantee clause and limited real-time verification mechanisms have fuelled distrust.

Climate Change and Upstream Pressures Rewrite the River

Thirty years on, the physical realities of the basin have changed dramatically. Climate change is altering monsoon patterns and accelerating glacial melt in the Himalayas, while intensive upstream abstraction for irrigation, industry and growing cities reduces the volume that reaches Farakka. Roughly 975 barrages and structures in India draw water before the river arrives at the measuring point, according to Bangladeshi experts. Population growth and rising demand on both sides have further strained the historic baseline.

In Bangladesh the consequences are visible every dry season. The Padma shrinks, navigation suffers, salinity advances inland, and agriculture in the southwest faces stress. Fishermen report dwindling catches. One observer noted that in recent years stretches of the river near Rajshahi have resembled a desert more than a living waterway. Bangladesh has responded by advancing its own Padma Barrage project, intended to store and regulate flows, yet its viability depends on predictable upstream releases.

Competing Voices Inside India

Inside India the picture is equally complex. Bihar leaders argue that the Farakka Barrage has worsened siltation and flooding in their state by raising the river bed, while diverting water southward for West Bengal’s benefit. JD(U) Rajya Sabha MP Sanjay Kumar Jha has urged the Centre not to renew the treaty in its present form, insisting Bihar’s irrigation, drinking-water and development needs must be factored in. West Bengal, meanwhile, wants adequate dry-season flows maintained for the Hooghly, Kolkata Port, industry and urban supply. External Affairs Minister S Jaishankar has assured Bihar that its requirements will be considered.

Indian officials have signalled a preference for handling discussions through the existing Joint Rivers Commission rather than creating new binding structures. Some reports suggest New Delhi may seek a shorter, more flexible arrangement of 10-15 years instead of another rigid 30-year lock-in, citing changed hydrological conditions and domestic needs.

Bangladesh’s Push for Guarantees and Broader Principles

Dhaka is determined to secure stronger protections. Water Resources Minister Shahiduddin Chowdhury Anee has called for a “guarantee clause” ensuring a minimum flow during the lean season – something present in the earlier 1977 interim agreement but omitted in 1996. Bangladesh also wants greater transparency in data sharing, consideration of the entire basin rather than solely the Farakka point, and recognition of climate impacts. Officials have indicated that if bilateral talks falter, Dhaka could explore international forums.

Bangladesh’s accession to the UN Watercourses Convention has strengthened its legal position, giving it a clearer basis to argue for equitable and reasonable utilisation and the obligation not to cause significant harm. Experts such as Professor AKM Saiful Islam of BUET have advocated a basin-wide approach that could eventually include Nepal, arguing that fair sharing is impossible when hundreds of upstream structures divert water before measurement.

In a recent analysis, economist S Nazrul Islam urged Bangladesh to shift from a purely commercial mindset to a nature-based approach that prioritises river ecosystems, while also ratifying the UN convention. Former ambassador Humayun Kabir has counselled pragmatism: extending or renewing the existing framework may be safer than risking an open-ended renegotiation in which India could seek to reduce Bangladesh’s share.

The Road to December and Beyond

Technical-level talks under the Joint Rivers Commission have continued, including joint inspections and measurements at Farakka in May 2026. Both sides confirm preparatory work is under way, yet core differences persist over the basis of calculation, the duration of any new pact, and the inclusion of minimum guarantees or climate-adjustment clauses. Political transitions in Bangladesh and domestic pressures in India have added layers of complexity.

The stakes extend far beyond the Ganges. India and Bangladesh share 54 rivers; only one has a formal water-sharing treaty. Success or failure on the Ganges will shape prospects for agreements on the Teesta and other shared rivers. It will also test whether South Asian water governance can adapt to a warmer, more variable climate and intensifying human demands.

As one recent commentary observed, the December deadline is not necessarily a cliff edge, but it is a political deadline of real consequence. Without renewed cooperation grounded in updated science, transparent data and mutual restraint, the Ganges risks becoming a source of friction rather than a shared lifeline. 

The clock is ticking – for the river, for the people who depend on it, and for the relationship between two neighbours whose futures remain intertwined by its waters.