ResearchAnalysis

The Ganges treaty at thirty

The 1996 treaty that shares the Ganges at Farakka in the dry months reaches the end of its thirty-year term on 12 December 2026. What the text says, where renewal stands, and what thirty lean seasons of modelled river flow suggest. Neutral between the two countries, and clear about what a model can and cannot show.

21 Oct 2026Trinetra research desk7 min readData from Sandhi
Key points
  • The treaty shares the flow at Farakka in ten-day periods from 1 January to 31 May. It was signed on 12 December 1996 for thirty years, renewable by mutual consent.
  • If the flow falls below 50,000 cusecs in any ten-day period, the two governments must consult immediately. India's release of at least 90% of Bangladesh's share holds "for the period of this Treaty".
  • As of 9 October 2026, India's foreign ministry said discussions sit within the Joint Rivers Commission; Bangladesh's ministers have asked for a guarantee clause. No renewal had been announced by 21 October.
  • In a global flood model, 87 of 450 ten-day periods from 1997 to 2026 fell below 50,000 cusecs, in 18 of 30 seasons, and none since 2021.
  • The model shows no trend in dry-season flow that can be told apart from year-to-year variation.

What the treaty says

  • When. Sharing applies in ten-day periods from 1 January to 31 May each year (treaty text, FAOLEX).
  • How much. When 70,000 cusecs or less reach Farakka, each side gets half. Between 70,000 and 75,000, Bangladesh gets 35,000 and India the balance. Above 75,000, India gets 40,000 and Bangladesh the balance. From 11 March to 10 May each side is guaranteed 35,000 cusecs in alternate ten-day periods (Annexure I).
  • Low flow. "In the event flow at Farakka falls below 50,000 cusecs in any 10-day period, the two Governments will enter into immediate consultations to make adjustments on an emergency basis" (Article II(iii)).
  • Measurement. A Joint Committee observes and records daily flows at Farakka and at Hardinge Bridge in Bangladesh (Article IV).
  • Floor. "For the period of this Treaty", without agreed adjustments, India releases at least 90% of Bangladesh's share (Article XI).
  • Term. In force from signature "for a period of thirty years", renewable on the basis of mutual consent (Article XII). Signed at New Delhi on 12 December 1996 (copy held by the Joint Rivers Commission, Bangladesh).

Where renewal stands

India's Minister of State for External Affairs told the Lok Sabha in July 2024 that the two governments had decided to begin discussions on renewal, and in August 2025 and February 2026 that those discussions were yet to commence (LSQ 833, LSQ 2210, LSQ 2405). The Joint Rivers Commission met in Kolkata on 22 May 2026 to review the treaty, after a joint observation of flows at Farakka; neither side issued a statement (The New Nation).

In August and October 2026 Bangladesh's Water Resources Minister said Bangladesh would seek a guarantee of its share in a renewed treaty (Business Standard, 19 Aug; ANI via NewKerala, 8 Oct). On 9 October India's Ministry of External Affairs said discussions on the treaty are held under the Joint Rivers Commission framework (ANI, 9 Oct). The next lean season begins on 1 January 2027.

Thirty dry seasons in a model

The Joint Committee's measured flows are not public in a form we could use, so Sandhi uses a model: the Global Flood Awareness System (GloFAS v4) reanalysis for a main-channel cell about 14 km downstream of Farakka Barrage, through the Open-Meteo Flood API. It applies the treaty's ten-day schedule to those modelled flows to show what the formula would imply. It makes no finding about compliance.

Mean modelled flow at Farakka in each lean season, 1997 to 2026 Columns show the mean modelled flow from 1 January to 31 May for each year. Gold columns are seasons in which at least one ten-day period fell below 50,000 cusecs in the model. The driest season was 2006 at 52,545 cusecs and the wettest 2020 at 117,716 cusecs. a period below 50,000 none below 50,000 50,000 cusecs, Article II(iii) 0k 25k 50k 75k 100k 125k 1997: 68,684 cusecs mean; 3 ten-day periods below 50,000 1997 1998: 98,252 cusecs mean; 0 ten-day periods below 50,000 1999: 53,925 cusecs mean; 7 ten-day periods below 50,000 2000: 79,342 cusecs mean; 0 ten-day periods below 50,000 2000 2001: 61,412 cusecs mean; 9 ten-day periods below 50,000 2002: 78,982 cusecs mean; 2 ten-day periods below 50,000 2003: 78,192 cusecs mean; 1 ten-day period below 50,000 2004: 83,102 cusecs mean; 0 ten-day periods below 50,000 2005: 68,925 cusecs mean; 0 ten-day periods below 50,000 2005 2006: 52,545 cusecs mean; 10 ten-day periods below 50,000 2007: 76,202 cusecs mean; 3 ten-day periods below 50,000 2008: 59,775 cusecs mean; 4 ten-day periods below 50,000 2009: 54,224 cusecs mean; 8 ten-day periods below 50,000 2010: 53,817 cusecs mean; 7 ten-day periods below 50,000 2010 2011: 66,468 cusecs mean; 2 ten-day periods below 50,000 2012: 70,024 cusecs mean; 2 ten-day periods below 50,000 2013: 71,359 cusecs mean; 4 ten-day periods below 50,000 2014: 87,901 cusecs mean; 0 ten-day periods below 50,000 2015: 100,318 cusecs mean; 0 ten-day periods below 50,000 2015 2016: 56,388 cusecs mean; 9 ten-day periods below 50,000 2017: 73,680 cusecs mean; 2 ten-day periods below 50,000 2018: 65,310 cusecs mean; 8 ten-day periods below 50,000 2019: 82,698 cusecs mean; 1 ten-day period below 50,000 2020: 117,716 cusecs mean; 0 ten-day periods below 50,000 2020 2021: 71,965 cusecs mean; 5 ten-day periods below 50,000 2022: 117,442 cusecs mean; 0 ten-day periods below 50,000 2023: 81,889 cusecs mean; 0 ten-day periods below 50,000 2024: 68,209 cusecs mean; 0 ten-day periods below 50,000 2025: 80,331 cusecs mean; 0 ten-day periods below 50,000 2025 2026: 103,212 cusecs mean; 0 ten-day periods below 50,000
Mean modelled flow at Farakka, 1 January to 31 May, by season. Gold: at least one ten-day period below 50,000 cusecs in the model. The 2026 season comes from archived forecasts, earlier seasons from the reanalysis. Source: Sandhi seasons.json, GloFAS v4 via Open-Meteo, retrieved 21 Oct 2026.
  • Across 30 seasons and 450 ten-day periods, the modelled flow fell below 50,000 cusecs in 87 periods, in 18 seasons. The last such season was 2021.
  • The driest season in the model was 2006, averaging 52,545 cusecs; the wettest was 2020, at 117,716.
  • From 11 January to 20 February the median modelled flow was about two thirds of the availability the treaty's schedule assumes. From 21 April to 31 May it was about 35% above it.
  • Mean dry-season flow rose by 5,714 cusecs per decade in the model, but the 95% interval runs from a fall of 1,583 to a rise of 14,366, and a Mann-Kendall test gives p = 0.10. That is not a trend that can be told apart from variation between years.

Model flows are not measurements. GloFAS represents the river at a coarse grid and does not know how the barrage is operated, so the numbers above describe what a consistent global model sees, not what the Joint Committee recorded. They are useful for comparing years with each other, not for settling any question between the two countries.

Why it matters on the frontier

Dry-season flow sets how far boats can move on the Padma and its distributaries, where chars emerge, and how salt water pushes into the delta. The same rivers swell in the monsoon: on 9 September 2026 the Ganga at Malda stood 69 cm above its extreme danger mark (WION). Shared, neutral numbers on both seasons help the people who negotiate the treaty and the people who live beside the river.

Sources

  1. Treaty between the Government of the Republic of India and the Government of the People's Republic of Bangladesh on Sharing of the Ganga/Ganges Waters at Farakka, 12 Dec 1996. FAOLEX copy and Joint Rivers Commission (Bangladesh) copy. faolex.fao.org, lpr.adb.org
  2. Ministry of External Affairs, Lok Sabha unstarred questions 833 (26 Jul 2024), 2210 (1 Aug 2025) and 2405 (13 Feb 2026). mea.gov.in
  3. The New Nation (Dhaka), "JRC meeting ends amid silence", May 2026. dailynewnation.com
  4. Business Standard, "Bangladesh seeks guarantee clause in renewed Ganges water treaty with India", 19 Aug 2026; ANI via NewKerala, 8 Oct 2026. business-standard.com, newkerala.com
  5. ANI, "MEA reiterates Ganga Water Treaty discussions held under Joint Rivers Commission framework", 9 Oct 2026. aninews.in
  6. Copernicus Emergency Management Service, GloFAS v4 reanalysis and forecasts, via the Open-Meteo Flood API (CC BY 4.0); compiled by Trinetra Sandhi, generated 21 Oct 2026. seasons.json, trend.json, timeline.json
  7. WION, Ganga at Malda above extreme danger mark, 9 Sep 2026. wionews.com
All research Model flows, not official measurements. Neutral between the two countries.