The river that holds a country together.
Pakistan was built along the Indus. An engineer on what the 1960 treaty actually did, why it is under strain, and what water security would really take.
Poster for Samia Journal, drawn in the house style. Every Journal piece gets one; no stock photos, no generated scenes.
Fly over Punjab in late spring and the country looks like a drawing made with a ruler. Canals run straight for miles, fields sit in exact rectangles, and every line of green leads back, eventually, to one river. The Indus rises in Tibet, cuts through the Himalaya and the Karakoram, and runs about 3,000 kilometres to the Arabian Sea near Karachi.1 Almost everything Pakistan grows depends on it.
I am an engineer, and the first thing engineers learn about the Indus is that it is not one river. It is a system: the main stem and five great tributaries, fed by snowmelt and the monsoon, stitched together by barrages and link canals into one of the largest contiguous irrigation networks on earth.2 The second thing we learn is that this system was cut in two in 1947.
A border drawn across the water
Partition placed the headwaters of several rivers in India and most of the irrigated land downstream in Pakistan. For thirteen years the two new countries argued over who could take how much. In 1960, after nearly a decade of talks brokered by the World Bank, Jawaharlal Nehru and Ayub Khan signed the Indus Waters Treaty in Karachi.3
The bargain was simple to state and hard to build. India got the three eastern rivers. Pakistan got the three western ones, and with World Bank financing it built the dams and link canals needed to carry western water to land that used to drink from the east: Mangla on the Jhelum, finished in 1967, and Tarbela on the Indus, finished in 1976 and still among the largest earth-filled dams ever built.5
The treaty survived three wars. What it was never designed to survive is a river that is changing underneath it.
Under strain
For sixty-five years the treaty was the quiet success story of a loud rivalry. That changed in April 2025, when India announced it would hold the treaty "in abeyance" after the attack at Pahalgam, and Pakistan said any attempt to stop or divert its share of the water would be treated as an act of war.6
The politics are real, but as an engineer I worry about a slower problem. Reservoirs fill with silt. Glaciers that feed the upper Indus are changing. Canals lose water to seepage long before it reaches a field. A treaty can divide a river; it cannot store one.
What water security would take
Not one megaproject, but a hundred unglamorous ones: lining canals, measuring every flow in real time, pricing water so it is not wasted, recharging aquifers, and maintaining what already exists. The engineering is known. The hard part, as ever, is deciding to do it.
Sources
- Encyclopaedia Britannica, "Indus River".
- World Bank, Indus Basin irrigation system overview.
- World Bank, "Fact Sheet: The Indus Waters Treaty 1960 and the Role of the World Bank".
- The Indus Waters Treaty 1960, full text, United Nations Treaty Series.
- Water and Power Development Authority (WAPDA), Tarbela and Mangla project records.
- Government of India and Government of Pakistan statements, April 2025, as reported by Reuters and AP.
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