Climate Change Is Straining Pakistan's Water. Tensions With India Could Make It Worse

As military tensions continue to flare up between India and Pakistan, India’s Prime Minister Narendra Modi vowed earlier this week to stop water from crossing the border into Pakistan, saying “India’s water will be used for India’s interests.”

On April 23, Modi suspended a 1960 treaty that allows the two countries to share water from the Indus Basin. Building infrastructure to stop the flow of water into Pakistan, however, would take India years to carry out, and the move would further strain the resources of a water-scarce country.

Pakistan’s water resources have already been burdened by climate change, as the country faces rising temperatures, droughts, and melting glaciers and superfloods that are impacting the timing of water flow. Now, India’s moves could exacerbate the crisis—and present long-term challenges for Pakistan’s agricultural sector. 

Many Pakistanis currently lack access to clean and reliable water sources—in part due to climate change. In the months after the 2022 floods killed at least 1,700 people, more than 10 million people were left without access to safe drinking water, according to a UNICEF report. “There’s been quite a lot of difficulty for local populations to have access to water on a consistent basis,” says Bhargabi Bharadwaj, research associate at the Environment and Society Center at Chatham House. “This is already being felt at local population level, even scrapping this most recent escalation on the Indus Water Treaty agreement.”

Why does India control Pakistan’s water supply?

When the South Asian subcontinent was cleaved by the British in 1947, boundaries were drawn that divided the Indus River along India and Pakistan. “The problem starts on day one,” says Hassaan Khan, assistant professor of urban and environmental policy at Tufts University.

Read more: How India Is Threatening to Weaponize Water in Its Conflict With Pakistan

Much of the headwaters are located in India, despite most irrigation systems falling in Pakistan. “Around 80% of Pakistan’s agriculture and the third of its hydropower depends on the water from the Indus Basin region,” says Bharadwaj. “There is a greater dependency on this basin for Pakistan than there is for India.”

The Indus Waters Treaty was drawn up in 1960 by the World Bank, and required the two countries to divide the river system’s water equally. The treaty included mechanisms to resolve disputes—and was designed to last in perpetuity. 

For India to cut Pakistan’s water supply altogether would be an impossible task. “Currently, India does not have the infrastructure capacity to really store excess water, which is what they’d be required to do if they’re kind of trying to cut away from letting this water reach Pakistan,” says Bharadwaj.

But still, experts say India could engineer small disruptions that would impact how much water flows into Pakistan. “Stopping the flow isn’t really possible,” says Khan. “What [India can do] is impact the timing of the flow—release more water one day and then stop. [It can] create these small disturbances, which, if they’re not properly managed by Pakistan, can have an impact on the agricultural system.”

The impact would likely largely be felt during the low flow season—from December to February—when there’s less water to begin with.

But Bharadwaj notes that the Indus Water Treaty was designed to withstand the many tussles the two countries have had over the years. “This isn’t the first time this has happened,” she says. “One of the very positive things about the Indus Water Treaty is that it has withstood two previous wars and another limited conflict between the two countries, and that can be, I think, largely attributed to the strength of its design.”

Why does Pakistan have a water crisis?

Pakistan’s water scarcity crisis can be traced back to before the country was founded. “The regions that now make up most of Pakistan as part of the Indus Basin, they’re alluvial plains, so they’re very fertile, but typically don’t have that much rainfall,” says Daniel Haines, associate professor in the history of risk and disaster at University College London whose research focuses on South Asia. “The ambition to increase the acreage of farmland outstripped the amount of water that was available.” 

As early as the 1930s and ‘40s, different regions of then colonial India were already disputing who would get what amount of water for agricultural projects, says Haines. 

Climate change and rapid population growth is now making things worse. Today, Pakistan is considered one of the most water-stressed countries in the world. And last winter was one of the driest in the country’s history, with the Pakistan Meteorological Department reporting 67% less rainfall than usual. According to the Germanwatch 2025 Climate Risk Index, Pakistan ranked as the most vulnerable country to the impacts of climate change in 2022, as it faced one of the costliest disasters in world history caused by the flooding—putting much of the country’s agricultural land at risk and impacting drinking water. But farmlands are also becoming unusable due to increasing droughts, pushing more people into cities and placing a strain on urban water supplies.

“Cities now are increasingly water stressed, because water supply hasn’t kept up with the increase in population,” says Khan. 

Over three-quarters of Pakistan’s renewable water resources come from outside its borders—mostly from the Indus Basin, and major cities rely on that for their drinking water. Any changes to the country’s water supply will have major impacts on agriculture and livelihoods for millions, says Haines. “Because the water system in Pakistan is already so stressed, any kind of major disruption to even the timing, let alone the volume, would potentially have pretty serious consequences.”