NDTV Explainer: Past, Present, And Future Of Indus Waters Treaty

For more than six decades, it was hailed as one of the world's greatest diplomatic success stories. It survived wars that redrew military maps, terror attacks that froze diplomatic ties, and decades of bitter hostility between India and Pakistan. Governments changed, armies mobilised, and peace talks collapsed, but one agreement quietly endured -- the Indus Waters Treaty. Today, however, it faces its toughest test.

Since India placed the treaty in abeyance following the April 2025 Pahalgam terror attack, New Delhi has actively begun reshaping its approach to the rivers that defined India-Pakistan water diplomacy since Independence.

The latest sign of that shift is the proposed Chenab-Beas Link Tunnel Project -- an ambitious 8.7-kilometre tunnel to divert water from the Chandra River, one of the headwater tributaries of the Chenab, into the Beas basin. At the same time, India has fast-tracked a series of hydroelectric projects on the western rivers of the Indus basin.

Recent reports suggest that the central government has identified priority irrigation and power generation, and other developmental projects, in the Indus River Basin in sync with its resolve to utilise additional waters of western rivers -- Indus, Jhelum and Chenab -- in Jammu and Kashmir and its neighbouring states in a time-bound manner.

Read: Story Of Indus Waters Treaty, Partition, Planning, Pak Impact

These are not just engineering projects. They represent a strategic shift on India's part -- from treating water as a shared resource insulated from politics to viewing it as part of a broader national security calculus, especially as a deterrent against Pakistan-sponsored terror attacks on Indian soil.

To understand why this moment is so significant, one has to return to the turbulent days when Pakistan was carved out of India.

When Borders Changed But Rivers Didn't

The midnight of August 1947 saw the birth of two Independent nations. But rivers do not recognise political borders. The mighty Indus and its tributaries had flowed across the region for centuries, sustaining one of the world's oldest civilisations long before modern states came into existence.

Partition created an immediate problem.

The headworks controlling several irrigation canals were located in India, while the vast canal network carrying water to millions of acres of farmland lay inside Pakistan. The new neighbours inherited a river system that neither could control independently. To prevent immediate disruption, both countries signed a temporary Standstill Agreement, which allowed water to continue flowing as before.

It was only a stopgap.

The real significance of control over the Indus River System can be understood from what followed in April 1948 when this agreement expired. The then East Punjab state government led by Chief Minister Gopichand Bhargava stopped water flowing through some canals into Pakistan.

For several weeks, India shut off the headworks feeding the Upper Bari Doab Canal, a crucial part of the interconnected Indus river system inherited from British rule. Naturally, this move sent the Pakistan government into a panic.

Then Prime Minister Jawaharlal Nehru, however, disagreed and wrote to Bhargava that India stopping the water supply to West Punjab (in Pakistan) would not lead to a settlement but rather to desperate measures and possibly to war. In a letter to him, he suggested that in the given circumstances, "the sooner our engineers tackle the problem in some of the ways that had already been suggested, the better it would be."

Ultimately, both India and Pakistan agreed on the Inter-Dominion Accord of May 4, 1948, which required India to provide water to the Pakistani parts of the basin in return for annual payments as a stopgap measure, with further talks to take place in hopes of reaching a permanent solution.

Supplies were restored in May 1948 after negotiations and a ceasefire, but the episode demonstrated something that would shape South Asian geopolitics for decades.

Nine Years To Solve A Problem That Seemed Impossible

In 1951, American statesman David Lilienthal proposed that instead of treating the rivers as a political dispute, India and Pakistan should approach them as an engineering challenge, with the World Bank acting as mediator.

The World Bank -- then called the International Bank for Reconstruction and Development -- assembled engineers, economists, diplomats and water experts from both countries.

Read: "Stand Unchanged": India Stays Firm On Indus Waters Amid Pak Threats

What followed was nearly nine years of painstaking negotiations.

Every river, every canal, every storage structure, and every engineering design became the subject of technical debate.

Finally, on September 19, 1960, Jawaharlal Nehru and Pakistani President Ayub Khan signed the Indus Waters Treaty in Karachi, with the World Bank as a mediator.

The Deal: Dividing Rivers Instead Of Sharing Them

Instead of sharing every river, the Treaty divided the river system.

India received exclusive rights over the three eastern rivers -- the Ravi, Beas, and Sutlej. Pakistan received the three western rivers -- the Indus, Jhelum and Chenab.

The numbers tell the real story.

The eastern rivers allocated to India carry roughly 33 million acre-feet (MAF) of water annually. The western rivers allocated to Pakistan carry around 135 MAF. In effect, Pakistan received nearly 80 per cent of the waters of the Indus river system, while India retained around 20 per cent.

Contrary to a common perception, India did not gain additional water through the treaty. Instead, it formally accepted the waters it was already using, while allowing Pakistan unrestricted use of the western rivers.

India was permitted only limited use of those western rivers within its own territory -- for domestic consumption, specified irrigation, storage within prescribed limits, and run-of-the-river hydroelectric projects subject to stringent engineering conditions.

The treaty also established the Permanent Indus Commission, ensuring that officials from both countries would continue meeting regularly even when diplomatic relations deteriorated elsewhere.

The Clause That Still Raises Eyebrows

Perhaps the least discussed provision of the treaty was also its most unusual.

India agreed to contribute around 62 million pounds to help Pakistan build replacement canals and water infrastructure after the river allocation.

It remains one of the rarest examples in international diplomacy where an upper-riparian state not only gave away the larger share of a river system but also financed infrastructure for the lower-riparian state to use that water.

When it was signed, many in the Indian opposition criticised the treaty as asymmetrical and unfair.

Why Many In India Considered The Treaty Unequal

While Pakistan received guaranteed flows from the western rivers, India's use of those rivers remained tightly regulated.

The treaty imposed strict limits on how much water India could store. It capped the irrigated cropped area that India could develop in the western river basin.

It prescribed detailed engineering specifications for hydroelectric projects, including restrictions on pondage and storage capacity. These obligations were seen as largely one-directional. Pakistan did not face comparable constraints on infrastructure within its own territory.

Supporters argued that such restrictions were necessary because India, as the upstream country, possessed the ability to influence downstream flows.

Critics maintained that the treaty effectively limited India's development opportunities within its own territory while providing Pakistan with guaranteed access to the larger share of the basin.

That debate simmered for decades without fundamentally altering the treaty.

Few international agreements have displayed the resilience of the Indus Waters Treaty. It remained in force through the wars of 1965 and 1971. It survived the Kargil conflict. It remained untouched after the 2001 Parliament attack, the 2008 Mumbai attacks and numerous military crises. Even when diplomatic dialogue ceased, officials from the Permanent Indus Commission often continued meeting. Yet beneath that remarkable stability, new tensions were emerging.

Rise In Energy Needs And Legal Battle

As India's energy needs grew, New Delhi increasingly focused on harnessing the hydropower potential of the western rivers through run-of-the-river projects permitted under the treaty. Pakistan viewed many of these projects with suspicion.

In 2017, it challenged India's Kishanganga and Ratle hydroelectric projects, arguing that aspects of their design violated treaty provisions. The dispute triggered one of the treaty's most complex legal confrontations.

In 2022, the World Bank appointed both a neutral expert and a Court of Arbitration to examine different aspects of the disagreements. India objected to parallel proceedings and questioned the jurisdiction of the Court of Arbitration.

The legal battle deepened.

In 2023, India formally sought to modify the treaty through bilateral negotiations. Pakistan declined.

Pahalgam Changed Everything

The turning point came not in a courtroom or negotiating room, but after a terror attack.

Following the deadly attack on civilians in Pahalgam in April 2025, India announced that it was placing the Indus Waters Treaty in abeyance. This move was in line with a previous warning from Prime Minister Narendra Modi after the Uri attack. PM Modi had famously said that blood and water cannot flow together.

Pakistan raised this issue before the Court of Arbitration. The court ruled that the treaty did not provide for unilateral abeyance and reaffirmed its jurisdiction. India rejected the ruling, calling the court illegally constituted.

In May 2026, the court issued another award on maximum pondage that reportedly favoured Pakistan's interpretation of limits on India's water-control capabilities. India again dismissed the award. The legal dispute remains unresolved.

Next Chapter Is Being Written On The Ground

Today, the focus has shifted from legal arguments to physical infrastructure.

The proposed Chenab-Beas Link Tunnel is emblematic of India's evolving strategy.

Alongside accelerated hydropower projects, it signals New Delhi's intention to maximise every entitlement available within its territory and potentially rethink decades of restraint that characterised the implementation of the treaty.

For Pakistan, whose agriculture depends heavily on the western rivers, these developments are being watched with deep concern.

For India, they represent a reassessment of an agreement negotiated under very different geopolitical circumstances.