Thirty years is a long time for any treaty to hold. The Ganges Water Sharing Treaty, signed on December 12, 1996 in New Delhi, has quietly governed how much dry-season water reaches Bangladesh for three decades. It survived governments of both signatory countries. The treaty ends on December 12, 2026. Talks on what replaces it are underway in Dhaka and New Delhi, but talks and treaties are not the same thing, and there is no guarantee the second will exist by the time the first anniversary arrives.
It is thus worth asking, calmly and now, rather than in a panic come December -- what happens if it doesn't'? Does Bangladesh simply lose its claim to the river, and hope India feels generous? It's a fair worry. Roughly forty per cent of the country's people depend, one way or another, on what the Ganges offers them each dry season; irrigation, drinking water, fisheries, a coastline that salt water hasn't yet swallowed. But the worry rests on a misunderstanding of how international law actually works. A treaty is not the only mechanism standing between an upstream state and an unchecked hand on the tap. There is a body of law underneath it, one that applies whether or not any two governments have bothered to sign anything.
An old argument, long settled
In 1895, the American Attorney General (in Bangladesh terms the law minister) Judson Harmon, arguing with Mexico over the Rio Grande, put forward the idea that a country could do exactly as it liked with water flowing through its own soil; the consequences or repercussions downstream be damned. It is a seductive argument if you happen to be in the upstream. And for a while this macho doctrine had followers. It does not have any left. No court of good standing has ever upheld it and no serious government defends it today. Even the United States within a decade abandoned this position and negotiated a water sharing deal with Mexico instead, for whatever its worth. The opposite argument or extreme that a downstream county can demand the river's flow, untouched, forever, collapsed just as quickly for the obvious reason that it would leave upstream states unable to build so much as an irrigation canal.
What survived and what actually governs today, is somewhat in between. States sharing a river keep their sovereignty over the water within their own territory, but that sovereignty comes with strings attached, use it reasonably, and don't wreck it for the neighbours. This isn't a theory dreamed up by academics. The Permanent court of International Justice (PCIJ) said as much in 1929, ruling that an international river creates a "community of interest" among the states that share it, a shared stake that no single riparian gets to override (Territorian Jurisdiction of the International Commission of the River Oder). This laid down the groundwork for modern customary international law. An arbitral tribunal echoed similarly in 1957 in a dispute between France and Spain over a lake in the Pyranees -- an upstream state doesn't need the downstream state's permission to build, but it does have to consult honestly, in good faith and actually listen.
What the world court has ruled
The clearest word on this comes from the International Court of Justice (ICJ) itself in a 1997 case between Hungary and Slovakia over a dam on the Danube. The court held that every state sharing a river is entitled to "an equitable and reasonable share" of it. The ICJ made it clear that it is just not a matter of what a particular treaty happens to say, but a rule of international law generally. Thirteen years later, ruling on a dispute between Argentina and Uruguay over a paper/pulp mill, the court went a step further. It stated that any state planning works that could seriously affect a shared river now has to carry out a proper environmental study and notify its neighbour before going ahead (Construction of pulp mill near Fray Bentos 2010). In 2015, in a border dispute between Costa Rica and Nicaragua regarding construction of a road over the San Juan river, the Court confirmed the same duty again. This is thus not a fringe legal theory. It is what we call the world court keeps saying, case after case, decade after decade.
A warning from the Indus
If anyone doubts these rules matter, look next door. The Indus Water Treaty of 1960 between India and Pakistan is the closest example South Asia as to a model of water diplomacy. This treaty held through two wars and endless political hostility, and when India and Pakistan genuinely disagreed over a hydroelectric project on the Kishenganga, they did not rattle sabres. They went to arbitration at the Hague, which in 2013 set a minimum flow India had to guarantee downstream. Both sides accepted it. For decades, that treaty was cited around the worked as proof that even hostile neighbours can manage a shared river through law rather than force.
Then in April 2025, after the Pahalgum incident, casing death of 26 civilians in India administered Jammu-Kashmir, India put the treaty "in abeyance". This was never done before even in the midst of outright wars between the countries. India has held that line through 2026 brushing aside or ignoring a fresh arbitral ruling against them. Whatever one makes of the underlying dispute, the lesson for Dhaka is blunt: a treaty's age and reputation are not guarantee of its survival. Bangladesh should plan for the Ganges relationship with clear eyes -- not comfortable assumptions.
Where this leaves Bangladesh
None of this is an argument for easing up on the push for renewed treaty -- quite the opposite. A proper agreement, with an updated flow formula, joint monitoring and a real dispute resolution mechanism, beats reliance on general legal principles every time. Customary law is real. However, it is broad by nature and broad rules are harder to enforce in a specific dispute than a number written into a treaty. Renewal , on terms that reflect today's hydrology rather than data from the 1950s through the 1980s, should stay Dhaka's top priority. This must dominate their minds through the Joint River Commissions, and at the highest political level.
However, even if December comes and goes without a signed successor, Bangladesh is not left with nothing. India remains bound, under the customary international law and the principles of the International Court of Justice itself has repeatedly affirmed, to use the Ganges reasonably, to avoid causing serious harm to Bangladesh's own use of the river, to notify and consult before undertaking any new works that would affect its flow, and to carry out a proper environmental assessment first. These are not favours India might choose to extend. They are legal obligations. And Bangladesh should say so clearly, repeatedly and everywhere it has a voice including the UN General Assembly. From now through December, and beyond if it must.
A river does not read treaties. It rises and falls according to decisions made far upstream, regardless of what is written on paper. However, the states that share it remain bound by law all the same, treaty or no treaty. Between now and December, Bangladesh has to remain focussed on two issues, if I may put it in that way -- negotiate hard for a fair renewal and make it unmissable to India, and its rights to the Ganges water were never written entirely in the ink of 1996.
Muhammad Nawshad Zamir is a Member of Parliament and a Barrister-at-law.
