NDTV Explains: Story Of Indus Waters Treaty, Partition, Planning, Pak Impact

On September 19, 1960 - after 13 years of tension brought on by the Partition and thanks to an intervention by the World Bank - India and Pakistan, led by Prime Minister Jawaharlal Nehru and President Mohd Ayub Khan, signed a treaty to share the waters of the Indus River system.

On signing the treaty, Nehru famously told Parliament India had "purchased a settlement'; "... if you like... we purchased peace to that extent and it is good for both countries," he said.

Over the years the Indus Waters Treaty, or IWT, has been seen as a successful water-sharing deal, all the more so because of the history of military tension between the parties involved.

The IWT has survived three wars - 1965, '71, and '99 - and several military clashes, as well as tension over parts of the accord itself, including India building the Kishanganga Dam in 2017.

But on April 23, 2025, India decided 'enough is enough', and announced the suspension of the IWT in response to the terror attack in Jammu and Kashmir's Pahalgam - an attack it believes was supported by the Pak military establishment, and in which 26 people were killed.

The treaty will stay suspended, India has said, till Pakistan takes concrete measures to end its support for cross-border terrorism, a plea that has been made frequently but with no success.

Indus Water Treaty, The History

In 1947, when the Partition occurred, India and Pakistan began disputing rights to the Indus River and its tributaries. The move to split, to partition, everything did not help.

The Partition left the Indus River system's headworks, i.e., structures that divert water from a river into a particular canal or canals, in India, and the channels it fed in Pakistan.

And so, India's East Punjab province stopped water - via canals - to Pak's West Punjab.

Pakistan the complained to the United Nations.

There was a short-term agreement in 1947 itself, but it wasn't till May 1948 that a proper water-sharing deal was reached. The Inter-Dominion Accord directed India to provide Pak with water.

In return, Pakistan would make annual payments.

But this agreement too soon broke down.

In 1951 a visiting American government official, David E Lilienthal, a flood control expert, suggested a solution, for a joint agreement under the aegis of the World Bank.

The suggestion, Lilienthal wrote later, also helped defuse growing military tension.

And then World Bank chief, Eugene Black, told the India and Pak governments the financial body was keen on helping two nations in whose economic progress it was already invested.

It took nine years - of consultations between engineers from each country and the World Bank, and for political machinations to be overcome - before the Indus Waters Treaty was signed.

Within those nine years, Pak argued that it should have rights to all the waters given its historical connections and the more pressing threat of its West Punjab province turning into a desert.

It was India, in response, that suggested the split that was finally accepted.

Pak's Anger Over IWT Solution

But before that solution was accepted, the Pakistan side made many furious endeavours to claim all of the Indus basin, i.e., the pre-Partition distribution of waters.

That the World Bank seemed to side with India further angered the Pak side.

And, for a while, it seemed the impasse would not only lead to a breakdown of these talks, but also increased military hostilities between Delhi and Islamabad. A lull followed. In 1954 talks resumed with India eager to find a solution given pending irrigation and development projects.

After six years of continuous negotiation, Pakistan finally buckled.

Even then, though, there was one last problem - the canals to be built in Pakistan to transfer water from rivers allotted to it. India was asked to pay for the construction, but it refused.

The solution was external financing, and that is how a multitude of other countries, including Australia, Canada, Germany (then West Germany), and even New Zealand played a role in settling the Indus Waters dispute.

Since then sharing of the waters has been relatively incident-free; a joint commission has overseen implementation of the accord and resolution of disputes.

So What Is The IWT?

In essence, it divides rights over the six major rivers that make up the Indus system - the Beas, Chenab, Sutlej, Ravi, and Jhelum, as well as the Indus itself.

The agreement gives India rights over the eastern rivers - i.e., the Sutlej, Beas, and Chenab - which amounts to an estimated 33 million acre feet, or MAF, of water annually.

And it gives Pakistan rights over the 135 MAF in the other three, the western rivers.

The agreement also gives India the right to use some waters from the western rivers, so long as its usage does not significantly affect the amount of water flowing into Pakistan.

These 'rights' allowed India and Pakistan to use its shares of the waters for irrigation and non-consumptive purposes, such as hydropower, pisciculture, etc. There are rules specifying usage in each case, with built-in measures to ensure no harm comes to the other during such use.

The IWT also has rules for building 'run of the river' hydroelectricity projects on the western rivers, i.e., those given to Pakistan, and includes provisions for Pakistan to raise complaint.

'Run of the river' projects refer to those that use the natural flow to generate electricity.

All of this is important, particularly for Pakistan.

Because the Indus, Jhelum, and Chenab don't originate in Pakistan; the Indus rises in China and a small part of it flows through India before it enters Pakistan, and the other two start in India.

So any construction - which if the IWT were still operational, would need consensus - on these rivers as they flow through India could, and probably will, impact water supply to that country.

By suspending the treaty India can bypass consensus requirements to build dams and other diversionary features on all six of these rivers, thereby crippling Pakistan.

Because the Indus system (including numerous smaller tributaries and canals) is Pak's main water resource, and the IWT accounts for nearly 80 per cent of supply for farms and homes.

Like India, Pakistan is an agrarian economy. But unlike India, Pakistan does not have multiple river systems feeding its farms. And with groundwater already at dangerously low levels, water from the Indus and its tributaries is possibly all that stands between it and famine and drought.

Exiting The IWT?

Can India entirely exit the Indus Waters Treaty?

That is unclear.

Pradeep Kumar Saxena, India's Indus Waters Commissioner for over six years, believes there is some wiggle room thanks to the Vienna Convention on Law of the Treaties. "... the treaty can be repudiated in view of the fundamental change of circumstances..." he told news agency PTI.

Other experts, however, believe there is no actual 'get-out-of-jail', or exit, clause in the IWT.

Renegotiation is, however, possible, and, indeed, many argue a long-pending need.

Meanwhile, this is not the first time India has used the IWT to respond to terror attacks from across the border. In 2019, after the Pulwama attack in which 40 soldiers were killed, Nitin Gadkari, then the Water Resources Minister, threatened to stop all water flowing from India.