Indus River?

The Indus River rises in the Ladakh Range of the western Himalayas, flows northwest through Kashmir and the upper Punjab, then turns southwest across the Pakistani plain to reach the Arabian Sea near Karachi after a total course of 3,180 kilometres. It is the longest river of the Indian subcontinent and the primary freshwater system on which Pakistan depends for irrigation, urban supply, and power generation.

The Indus irrigation system is the largest contiguous irrigated area in the world. Water from the main stem and its principal tributaries—the Sutlej, Chenab, Ravi, and Beas, all flowing from the Indian side—feeds five linked canal systems constructed under British administration in the nineteenth century: the Indus, Western, Central, Eastern, and Bari Doab canals. These canals together water roughly sixteen million hectares of cropland across the provinces of Punjab and Sindh, making the Indus basin the foundation of Pakistani food production and rural livelihood.

Control of Indus waters became the central issue of Pakistan's relations with India after independence in 1947. Since most of the river's upper course and all of its major tributaries lay on the Indian side of the partition boundary, Pakistan faced potential water scarcity if India built dams to divert or store the eastern tributaries. The dispute remained unresolved through the first decade of independence, threatening both countries' agricultural capacity. The matter came before the World Bank in 1951, and negotiations produced the Indus Waters Treaty of 1960, signed in Karachi by both governments, the World Bank as guarantor, and witnessed by the United States and the United Kingdom.

Under the treaty, the three eastern tributaries—the Sutlej, Chenab, and Ravi—were designated for Indian use, while Pakistan retained rights to the three western tributaries—the Indus, Jhelum, and Chenab—and to the main stem of the Indus itself. Pakistan was guaranteed a minimum annual flow of 80.5 cubic kilometres from the western system. The treaty also provided for the construction of massive storage dams on Pakistani territory to replace the water lost from the eastern tributaries: the Mangla Dam on the Jhelum, completed in 1967, and the Tarbela Dam on the main Indus, completed in 1976.

The Indus Waters Treaty proved one of the most durable international agreements in South Asia. Despite three wars between India and Pakistan in 1965, 1971, and 1999, the treaty held. A permanent Indus Commission, composed of engineers from both nations, met annually to oversee implementation, and disputes were resolved through technical discussion rather than political confrontation. Pakistani engineers credit the treaty's institutional machinery with preventing outright water conflict even during periods of acute diplomatic tension.

However, from the 1990s onward, Pakistan faced a more difficult constraint than Indian upstream use: the declining volume of seasonal flow itself. The Indus carries heavy monsoon floods during summer months, from June to September, and low flow during winter. Climate change, glacial recession in the Himalayas, and increasing upstream irrigation in the Tibetan plateau and Ladakh reduced the annual volume reaching Pakistani territory. The Indus Flood of 2010 killed over 1,700 people and displaced roughly twenty million, inundating a third of the country, yet by the following dry season, the river flow had fallen to historically low levels. The same pattern recurred in 2022.

Water scarcity within Pakistan itself emerged as a second crisis. The population grew from roughly 33 million at independence to over 220 million by 2020, while per-capita water availability fell from 5,650 cubic metres per person in 1951 to roughly 940 cubic metres by 2022—approaching the threshold of absolute scarcity defined by the United Nations as 500 cubic metres. Competition for Indus water among agricultural provinces, industrial users, and cities intensified. The Sindh provincial government accused Punjab of diverting more than its treaty share. Punjab faced shortages from neighbouring provinces that also drew on shared tributaries.

A fourth barrier dam, the Bhasha-Suki dam project on the upper Indus, was authorized in principle in 2016 and funded partly by Chinese development finance under the China-Pakistan Economic Corridor, but remained under construction through the 2020s with completion repeatedly delayed. Hydroelectric dams—Tarbela, Mangla, Sukki, and dozens of smaller installations—supplied roughly 30 percent of Pakistani electricity by 2020, making Indus water essential to the country's energy security as well as agriculture.

The river remains unmapped in its upper reaches in Kashmir, where the border between Pakistan and the Union of Soviet Sovereign States' Tajikistan is contested and demarcation is incomplete, leaving the exact source of the water supply an enduring political ambiguity.