The Narendra Modi government has decided to initiate talks with Pakistan on the Indus Waters Treaty, and rightly so. After the Uri incident our Prime Minister said, “blood and water cannot flow together.” The truth is that the flow of blood can be stopped, but water will continue to flow.

The geography makes it next to impossible for waters from the Indus, Chenab and Jhelum. Yet there is reason to revisit this treaty, because of Pakistan’s persistent misuse of the provisions of the IWT that enable it to adopt a dog in the manger attitude to prevent or delay any development of hydel projects on the three rivers that is permitted by the treaty. This must stop.

The Indus river system has a total drainage area exceeding 11, 165, 000 sq.kms. Its estimated annual flow stands at around 207 km3, making it the twenty-first largest river in the world in terms of annual flow. It is also Pakistan’s sole means of sustenance. The British had constructed a complex canal system to irrigate the Punjab region of Pakistan. Partition left a large part of this infrastructure in Pakistan.

The World Bank brokered the IWT between India and Pakistan after many years of intense negotiations to allocate the waters of the Indus river basin. Prime Minister Jawaharlal Nehru and President Ayub Khan signed the treaty in Karachi on September 19, 1960. According to the IWT, control over the three "Eastern" rivers — Beas, Ravi and Sutlej — was given to India, while control over the three "Western" rivers — Indus, Chenab and Jhelum — to Pakistan.

On the face of it the pact is seen as generous to Pakistan as it gives the lower riparian state 80% of the water of the western rivers. But the reality is that IWT makes a virtue of a necessity, as it is the geography of the region that decides this rather than any altruism.

The main Kashmir valley is just a hundred kms wide at its maximum and 15,520.30 km2 in area. While the Himalayas divide the Kashmir valley from Ladakh, the Pir Panjal range, which encloses the valley from the west and the south, separates it from the great plains of northern India. This picturesque and densely settled valley has an average height of 1,850 metres above sea-level but the surrounding Pir Panjal range has an average elevation of 5,000 metres.

Thus the Pir Panjal range stands between the Kashmir valley and the rest of the country and is an insurmountable barrier that precludes the transfer of water anywhere else. And neither do the contours of the Kashmir valley allow for more waters to be stored in any part of it. Since the waters cannot be stored or used by diversion elsewhere it has to keep flowing into Pakistan.

Of the three Western rivers “given” to Pakistan, the Indus, which debouches from Indian territory near Kargil and then flows entirely in Pakistan, controlled territory. The Jhelum originates near Verinag near Anantnag and meanders for over 200 kms. in the Kashmir valley before it enters Pakistan occupied Kashmir. After flowing through Srinagar it fills up the Wular Lake and then traverses past Baramulla and Uri into POK. The run of the river hydel projects constructed on it supply most of the electricity to the Valley.

The Chenab, also known as Chandrabhaga, originates in Lahaul Spiti in Himachal Pradesh and flows through the Jammu region into the plains of the Pakistani Punjab. The catchment of Chenab is elongated and narrow. The catchment area of the Chenab is mostly in India. But the Chenab runs through deep valleys and the river drops by as much as 24 metres. per kilometre, imposing physical constraints and huge economic costs on harnessing it.

The three Eastern rivers allocated to India by the IWT are Beas, Ravi and Sutlej. These waters sustain agriculture in Punjab and to some extent Haryana and are substantially used. What enters Pakistan is usually just enough to keep the stream flushed. But nevertheless Pakistan has from time to time blamed India for its floods and the sudden and deliberate release of storage gates.

The question that still remains is about the Jhelum waters. Dr Shakil Ahmad Romshoo, head of the earth sciences at the geology and geophysics department, University of Kashmir recently said: “Let us assume we stop the water supply for the sake of argument. Where would the water go? We do not have infrastructure to store this water. We have not built dams in J&K where we can store the water. And being a mountainous state, unlike Tamil Nadu or Karnataka, you cannot move water to another state. So you cannot stop the water technically.”

But even if it can be done, climate change is upon us with severe implicit consequences for both countries, but mostly for Pakistan. The Indus river basin is fed mostly by glacier melt, unlike the Ganges and Brahmaputra basins, which are fed mostly by the monsoons. Since climate change is now affecting the Himalayan glaciers the water patterns in the Indus river basin are already showing changes. Hence Pakistan constantly keeps up a drumbeat of false charges about the non-adherence to the IWT by India.

But will there be enough water for very long? Widely referenced estimates indicate a troubling long-term trend for the flow of the Indus river basin. River water provides 80 percent of all irrigation water for Pakistan’s critical agriculture sector.

These water sources are already near their limits, with most water diverted to northern Pakistan’s agricultural regions at the expense of the south. In fact, so much water is diverted from the Indus before it reaches the ocean that seawater has invaded the river channel miles inland.

Based on current projections, the Indus River system is expected to fall below 2000 flow levels between 2030 and 2050. The drop-off is estimated to be most serious between 2030 and 2040,

with a new equilibrium flow of 20 percent below that of 2000 reached after 2060. Not only is Pakistan running out of water, it seems to be soon running out of time.

Mohan Guruswamy is a scholar and an author. Views expressed are his own.