The Ganga Is Drying, The Indus Is Rising: Study Flags Threat To India's Water Security

Last Updated:February 17, 2026, 17:27 IST

IIT Gandhinagar study reveals Indus Basin flow rose 8% while Ganga Basin declined 17%, threatening South Asia's water security and challenging the Indus Water Treaty

The two largest river systems of the Indian subcontinent, the Indus and the Ganga, are showing sharply contrasting trends, with one witnessing a rise in water flow and the other facing a significant decline. A recent study by IIT Gandhinagar, published in the journal Earth’s Future, has raised serious concerns over South Asia’s long-term water security.

Researchers analysed data from 1980 to 2021 and found that over the past four decades, the flow in the Indus Basin has increased by around 8%, while the Ganga Basin has recorded a steep decline of nearly 17%.

The study is significant for its use of high-resolution physical models and its close examination of the relationship between rainfall, groundwater, river discharge and irrigation pumping. According to Professor Vimal Mishra of IIT Gandhinagar, the shift is not only an environmental concern but also has the potential to challenge decades-old water-sharing arrangements between India and Pakistan.

Scientists warn that the decline in the Ganga’s flow represents the fastest reduction in the past 1,300 years and could affect millions of people who depend on the river system.

Why is the flow of water increasing in the Indus River?

Researchers attribute the increase in water levels in the Indus River system largely to Western Disturbances and changing monsoon patterns. Studies show that the main Indus River and its western tributaries, including the Jhelum and Chenab, have seen a rise in water levels. However, this increase is not uniform across the basin.

The eastern tributaries, such as the Ravi and Sutlej, are witnessing a decline despite the overall rise in the basin’s flow. These rivers fall under India’s share as per the Indus Water Treaty, and their reduced flow could pose serious challenges for agriculture in the region.

Who is the real villain behind the drying up of the Ganga Basin?

Low rainfall alone is not responsible for the declining water flow in the Ganga Basin. The study indicates that rainfall in the region has reduced by about 10%, but the primary reason is the extensive extraction of groundwater for irrigation.

In several parts of the Ganga Basin, nearly 50-70% of the river’s flow is sustained by groundwater. As large-scale pumping continues, the amount of water feeding into the rivers has declined. In some stretches of the Yamuna and the upper Ganga, the situation has become so critical that river water is seeping into depleted underground aquifers instead of being replenished by them.

Will this impact the Indus Water Treaty?

The changing behaviour of river systems could directly influence the 1960 Indus Water Treaty. India suspended the treaty in April 2025 following the Pahalgam attack and has since been fast-tracking hydropower projects to utilise part of its western river share.

Professor Mishra noted that climate change and increasing human pressure on water resources have created a need to reassess long-standing water-sharing arrangements. Pakistan’s agriculture depends heavily on the Indus’ main flow, while declining groundwater levels in Indian Punjab are adding to the region’s water stress.

What are the solutions to avoid a water crisis?

Researchers have cautioned that treating rivers and groundwater as separate systems will only deepen the crisis. To protect the Ganga Basin, there is an urgent need to reform irrigation practices and promote water-efficient crops through diversification.

The study stresses that water must no longer be treated as a free and unlimited resource. Without strict groundwater regulation and climate-sensitive management strategies, scientists warn that it will be difficult to halt the rapid decline in the Ganga’s flow.

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