On February 21, amid the furore over whether Prime Minister Narendra Modi was shooting for a documentary at Corbett National Park after a suicide bomber attacked a Central Reserve Police Force convoy in Kashmir’s Pulwama district, his water resources minister took to Twitter to make an announcement.

The government had “decided to stop our share of water which used to flow to Pakistan”, tweeted Union Water Resources Minister Nitin Gadkari. “We will divert water from Eastern rivers and supply it to our people in Jammu and Kashmir and Punjab.”

He was referring to the waters of the Indus river system, which are shared between Pakistan and India under the Indus Waters Treaty of 1960. This is not the first time that India has threatened to cut off water supply to Pakistan as punitive action.

In 2016, when an army camp at Uri in North Kashmir was attacked by suspected Jaish-e-Mohammad militants, the Indian government had blamed Pakistan for supporting the group. Modi had declared that “blood and water cannot flow together” and the government had threatened to storm out of the treaty. Months later, it resumed dialogue with Pakistan on the implementation of the treaty.

This time, the Pakistan government appears unfazed, saying it had no problem if India diverted water from the eastern rivers flowing out of the Indus, since that would not be a violation of the treaty. Soon afterwards, an official from the water resources ministry clarified Gadkari was only speaking of fully utilising India’s share of the Indus waters, and that this was an old plan.

At a time when Prime Minister Narendra Modi was under fire, Gadkari’s announcement may have been more of a diversionary tactic than an actual threat. That may be all for the best: walking out of the Indus Waters Treaty would not only be an explosive diplomatic move, it would also have terrible human costs.

The treaty

The Indus Waters Treaty is the fragile barricade that has stopped the two countries from plunging into disastrous water wars, even through seven decades of conflict. It deals with the six rivers of the Indus water basin. Under the British administration, this basin was fertile, uninterrupted agricultural territory. With Partition, India became the upper riparian state overnight.

On April 1, 1948, as hostilities broke out between the two fledgling nations, India cut off water supply from the Sutlej, which flowed across the border into Western Punjab, threatening agriculture in Pakistan. Status quo was restored days later, with the Inter Dominion Agreement, under which India was to continue supplying water for irrigation until Pakistan developed other water resources.

After 12 years of negotiation, mediated by the World Bank, the two countries signed the treaty in Karachi in 1960. It gave India “unrestricted use” of the eastern rivers, the Sutlej, Ravi and Beas. Pakistan had unrestricted use of the western rivers, the Chenab, Jhelum and Indus.

The treaty granted India the use of the western rivers for domestic, non-consumptive and agricultural uses. They could also be used for the generation of hydroelectricity, provided India followed conditions listed under Annexure D of the treaty – that these should be run-of-the-river projects with no live storage, among other things. India would have to furnish Pakistan with the details of the projects.

In effect, Pakistan got 80% of the water from the Indus river system and India 20%, or 33 million acre feet out of 168 million acre feet of water. If disputes arose, the two parties would try to solve them bilaterally first. Appointing a “Neutral Expert” and approaching the International Court of Arbitration are other options.

Drawing water

At present, India uses 93%-94% of the water allocated to it in the eastern rivers and the rest flows to Pakistan. Gadkari’s statement suggested that India would use up this remaining 6% to 7% of the water allocated to it, or 1.2% of the total supply. But, as some engineers point out, a part of the water will inevitably escape because of geographical factors and hydrological extremes. Not all of the unutilised water can be harnessed.

Three projects, in the works for some time now, are to exploit this unused 6-%7%: the Ujh dam, meant to be a hydroelectricity and irrigation project in Jammu’s Kathua district, the Shahapur Kandi Project on the Ravi and a second Ravi-Beas link, fiercely opposed by Punjab for years. These projects were reportedly put on a fast track after Uri, a claim which Gadkari has now repeated. These are supposed to supply India’s drinking water needs, feeding into the Renuka Dam project in the Yamuna River Basin. In January this year, the Centre signed a memorandum of understanding with six states for the project. None of this would affect Pakistan significantly, neither does it violate the terms of the treaty.

There have been disputes. Pakistan has objected to at least four hydroelectric projects developed by India. The two main bones of contention that remain are the Ratle hydroelectric project on the Chenab and the Kishenganga project on the Jhelum. The two countries also differ on the dispute resolution mechanism. While Pakistan has approached the court of arbitration, India wants the appointment of a neutral expert.

The costs

As India debates on the next course of action on the Pulwama attack, which it believes Pakistan actively supported, violating the the treaty and choking off water supply to its neighbour may still be an option. But this could have dangerous results.

First, there are the logistical hurdles. India needs to build up storage capacities before it can stop water flowing from the western rivers into Pakistan. At present, it cannot halt water supply without flooding Jammu and Kashmir. Second, it cannot ignore the possibility of China, Pakistan’s staunch ally, of taking retaliatory measure. India and China share crucial cross-border rivers like the Brahmaputra, with no treaties to regulate water sharing. Should China react in kind, it could mean extreme distress for India’s North East. Third, walking out of a crucial treaty that has held, despite its perceived flaws, through decades of conflict, could only end in India losing policial cache in international arenas.

Pressures on both countries have increased as rivers run dry and water shortages grow more acute. Pakistan may be much more dependent on the Indus river system than India is. It covers 65% of the country’s area compared to 14% of India’s. The Indus Basin Irrigation System is the source of water for most of its agriculture, accounting for rain and groundwater. Last year, shortages in this system delayed the sowing of the country’s main cash crops. Cutting off this precious, dwindling source of water would mean terrible human costs for millions living there.

While India tries to hold the Pakistan government accountable for its alleged involvement in cross-border attacks, it should not punish the millions of Pakistani citizens trying to make do with less and less water every year, just like their counterparts this side of the border.