There is a river that has flowed through the heart of Pakistani Punjab for centuries. Farmers along its banks have measured their seasons by it, calibrated their sowing to it, and built civilisations around the certainty of its arrival.
The Chenab is not merely a river to Pakistan. It is a lifeline. And for the first time in modern history, that lifeline has an adversary with both the intent and the infrastructure to control it.
India’s decision to fast-track construction of the Chenab-Beas Link Tunnel – an 8.7-kilometre underground conduit designed to divert waters from the Chandra River, a Chenab tributary in Himachal Pradesh, through the Pir Panjal mountain range into the Beas basin – has sent a tremor through Islamabad that is not seismic but strategic.
The -2,600-crore project, backed by a 19-metre barrage and supporting hydraulic infrastructure, is being framed by New Delhi as a domestic hydropower initiative. Pakistan, its water ministries, its agricultural economists, and an increasingly alarmed public see it as something categorically different: the deliberate dismantling of a 64-year-old agreement that once stood as proof that even enemies could be civilised about water.
Pakistan warns that New Delhi’s tunnel project beneath the Pir Panjal is not merely an engineering initiative. It is the opening shot in a new and dangerous form of warfare.
That agreement is the Indus Waters Treaty. And its effective collapse – India formally served notice of intent to modify the treaty in 2023, citing changed circumstances – may rank among the most consequential and underreported geopolitical developments of this decade.
The Treaty That Held Through Wars
To understand what is now at stake, one must first appreciate what the Indus Waters Treaty actually was, and why its durability for more than six decades was considered something close to a diplomatic miracle.
Brokered by the World Bank and signed in 1960 by Prime Minister Jawaharlal Nehru and President Ayub Khan, the IWT divided six rivers of the Indus system between the two nations with surgical precision. The three eastern rivers – Ravi, Beas and Sutlej – were allocated to India. The three western rivers – Indus, Jhelum and Chenab – were designated primarily for Pakistan, with India retaining limited and specifically defined rights for run-of-river hydropower generation and non-consumptive uses.
What made the treaty remarkable was not its technical architecture but its political resilience. It survived the 1965 war. It survived the 1971 war. It survived Kargil, the Parliament attack, the Mumbai attack, and decades of near-continuous hostility.
For 63 years, through crises that brought two nuclear-armed states to the brink of open conflict, water continued to flow according to the treaty’s terms. Diplomats, international lawyers, and development economists held it up as evidence that shared-resource agreements could outlast political enmity.
The IWT was, in that sense, more than a water treaty. It was an institutional argument for the possibility of South Asian civilisation.
That argument is now being withdrawn.
The Architecture of Diversion
The Chenab-Beas tunnel does not exist in isolation. It is the most visible recent element of what water-policy analysts describe as a comprehensive upstream utilisation strategy that India has been constructing, project by project, across the Chenab basin for more than a decade.
The Ratle hydropower project on the Chenab, with a capacity of 850MW, has been a source of sustained objections by Pakistan at international arbitration forums. The Pakal Dul dam on the Marusadar River, a Chenab tributary, is under active construction. The Kiru and Kwar hydropower projects on the Chenab mainstream are advancing through various stages of development.
Each project, taken individually, falls within or near the boundaries of what India argues is permissible under its treaty rights. Taken collectively, they constitute an infrastructure architecture of a different order entirely.
The Chenab-Beas tunnel accelerates and deepens this architecture. Unlike the run-of-river hydropower projects that India has defended as treaty-compliant, a trans-basin diversion – physically transferring water from the Chenab watershed into the Beas basin – represents a qualitative escalation.
Water diverted into the Beas does not return to the Chenab. It does not eventually cross the border. It is, in the most literal hydrological sense, removed from Pakistan’s portion of the treaty allocation.
And the precedent being established – that India may physically extract water from a western river basin into an eastern one, outside any treaty framework – is one that is legally indefensible by India and strategically alarming for Pakistan.
Pakistan’s Agricultural Civilisation at Risk
The existential weight of this question is not abstract. Pakistan’s economy remains fundamentally agrarian. Agriculture contributes roughly a quarter of GDP, employs close to 40 per cent of the labour force, and underpins the food security of a nation of 240 million people.
The Indus Basin irrigation system – the largest contiguous irrigated landscape on Earth – is the physical foundation of that economy.
The Chenab River is central to Pakistani Punjab’s irrigation network. It feeds the Trimmu and Islam headworks, which distribute water across canal systems irrigating millions of acres of wheat, cotton, sugarcane and rice. Farmers in Jhang, Chiniot, Hafizabad and across the breadth of central Punjab calibrate their agricultural decisions to seasonal Chenab flows with a precision refined over generations.
Any reduction in those flows – even gradual, even seasonal – cascades through the agricultural economy with consequences that extend far beyond the riverbanks. Reduced irrigation availability in a single growing season can translate into crop failures, debt spirals for smallholder farmers, displacement and social instability in regions already under pressure from poverty and climate stress.
According to estimates, cumulative Indian upstream development could reduce Chenab flows to Pakistani headworks by 15 to 25 per cent during pre-monsoon months over the next two decades. The economic consequences of even the lower bound of that range would be severe and potentially destabilising.
These are not the projections of alarmists. They are considered technical estimates of government hydrologists working from established engineering data. And they are projections that, as India accelerates its upstream infrastructure programme, are moving from the category of worst-case scenario toward something that resembles a planning assumption. (To Be Concluded)
The writer is a freelance columnist