Blood and water can’t flow together,” declared a belligerent Indian Prime Minister Narendra Modi on September 26, 2016 in the wake of 19 Indian soldiers dying in a militant attack on Uri military base, just inside Indian-administered Kashmir. Holding Pakistan responsible for the violence, Modi promised to unshackle India’s policy of “restraint” — implying that India was now going to hurt Pakistan by choking its water supply.

For the people of Pakistan, a nation dependent upon agriculture for its survival, the Indus rivers are their lifeline. As it is, Pakistan is ranked second, after China, in the Water Shortage Index, highlighting the vulnerability of the Pakistani population to frequent water shortages. Modi’s proclamation generated lots of nationalistic hyperbole in the two nuclear-armed twins but also inflicted some damage: many on this side of the border are perturbed about Modi making good on his threat and stopping water supply to Pakistan.

Can Modi turn the taps off immediately?

Can Modi turn off the taps and choke Pakistan’s rivers?

Not quite.

The Indus Waters Treaty of 1960, which governs water sharing arrangements between India and Pakistan, outlines a framework for how either country can exploit water potential and how they can’t. While the Indus Waters Treaty is upheld, India cannot turn the taps off — in fact, it does not have the capacity at the moment to do so either — but it can definitely delay the release of water flows. And historically, India hasn’t been averse to using this tactic when relations with Pakistan turn sour. This time has been no different.

Also read: International Law on Water Rights

In a story printed in the October 12 edition of Dawn, irrigation department officials warned of a record reduction of water levels at Head Marala in the Chenab. The fear is that water shortage in the river and two of its canals, Marala-Ravi Link Canal and Upper Chenab Canal, can adversely affect the sowing of crops particularly in Sialkot, Gujrat, Gujranwala and Sheikhupura districts. The situation has worsened at the time of this report going into print.

The cultivation cycle in the subcontinent is divided into two seasons: khareef (monsoon) and rabi (winter). Khareef sowing starts in July or even June while the sowing of rabi crops begins in September and October, depending upon glacial melts and the amount of rains. The water flows in the Indus system varies exponentially in different months. Up to 90 per cent of flows can be accounted for during July to September.

For rabi crops such as wheat, pulses, onions, tomatoes and potatoes, timing is crucial. With October at an end, the record reduction of Chenab water flows can translate into delayed rabi sowing, which in turn will adversely impact produce for local consumption in the coming season and lead to price inflation.

In practical terms, consider this: tomatoes are being sold in the market at 25 rupees per kilo today; expect this price to rise manifold in the coming year. This is besides the food and income insecurity that thousands of growers in Punjab and Sindh will be pushed into.

A crisis is certainly brewing.

Beyond hyperbole and nationalistic fervour, the two South Asian giants need to be at the negotiating table. Normally a dispute like the one reported by Dawn on October 12 could have been resolved at a meeting of the Indus water commissioners, mandated by the Indus Waters Treaty to be held once a year. But the Indian assertion that these meetings will resume only once “an atmosphere free of terror is established” spells disaster for our farmers. The only safeguard that the Indus Waters Treaty offered Pakistan was through the Permanent Indus Commission whose meetings India has been routinely flouting under one pretext or the other. If the situation persists, Pakistan will have no option but to take the matter through the cumbersome route of World Bank and international arbitration. All through this period, India will enjoy undue exploitation of water resources at the expense of the people of Pakistan.

What can India not do?

Caught in nationalistic fervour, hawks in the Indian media have been blaming their previous governments for failing to exercise a water offensive like the one PM Modi is intent on implementing.

Indeed, India can hypothetically terminate the Indus Waters Treaty and restrict even the rivers flowing into Pakistan through the diversion of Indus rivers waters. But when it comes to practice, this position remains untenable.

The waters of the Indus rivers flow through deep gorges of the Karakoram and Himalayan mountains. The only way to divert water from here is to tunnel through hundreds of kilometres of the world’s highest and toughest mountains.

Granted that all technical problems have technical solutions. However such an undertaking would be financially prohibitive, technically extremely challenging, and with minimal cost-benefit ratios. The longest tunnel dug in the world is the Gotthard Base Tunnel to facilitate rail travel. Although it is being drilled for the last 22 years through the Swiss Alps, it is merely 57 kilometres long and has already incurred an estimated cost of 12 billion US dollars. For India to divert waters of the western Indus basin rivers for meaningful use, it will have to dig up to 300 kilometres of tunnels.