Water Stress Hits Half of World’s Largest Cities, Experts Warn

Published: 22 January 2026. The English Chronicle Desk. The English Chronicle Online.

Half the world’s largest cities are now experiencing extreme water stress, a growing global concern. Analysis shows that almost 50 of the 100 largest cities face water scarcity, with 39 in regions classified under “extremely high water stress.” Water stress occurs when water withdrawals for public supply and industry approach the limits of available resources, often worsened by mismanagement and climate pressures. London, New York, Beijing, and Rio de Janeiro are all facing this challenge, highlighting the urgent need for sustainable water strategies.

New mapping by Watershed Investigations and data from the Guardian reveal how these cities sit in highly stressed catchments. For example, Delhi, Los Angeles, and Bangkok are flagged as highly stressed, while Tokyo and Lagos are in wetter regions showing temporary relief. UCL scientists also analysed NASA satellite data showing trends over two decades, indicating which cities are drying and which are getting wetter. Chennai, Tehran, and Zhengzhou show rapid drying, while Tokyo, Kampala, and Lagos show increasing water accumulation.

Approximately 1.1 billion people live in metropolitan areas within regions showing strong long-term drying, compared to 96 million in wetter urban zones. While this satellite data is coarse, it provides early warning signals for urban water security, prompting governments to reassess infrastructure resilience. Urban centres in Asia, especially northern India and Pakistan, face the strongest drying trends, while sub-Saharan African cities dominate wetter zones.

Tehran, now experiencing its sixth consecutive year of drought, is nearing “day zero,” the point when municipal water supply could halt completely. Authorities have warned of possible evacuations if conditions worsen. Cape Town and Chennai have both experienced near day zero scenarios, reflecting a broader global challenge for rapidly growing cities.

Professor Mohammad Shamsudduha, an expert in water risk reduction at UCL, said monitoring total water storage from space provides critical insights into emerging water insecurity, allowing policymakers to anticipate crises before they occur. Similarly, UN reports highlight that global water resources have entered a state of permanent deterioration, where poor management rather than climate change alone drives scarcity. Prof Kaveh Madani, director at the UN University Institute, stressed that mismanagement intensifies climate pressures, likening it to a recession atop bad governance.

The World Bank has highlighted declining global freshwater reserves, losing roughly 324 billion cubic metres annually—enough water for 280 million people. This loss affects river basins worldwide, signaling long-term challenges for cities dependent on these water systems.

In the UK, projections indicate that by 2055, England may require an additional 5 billion litres daily to meet public water demands, over a third of current supply. Agriculture and energy sectors may need an extra 1 billion litres per day. Groundwater resources offer a more climate-resilient alternative, according to Shamsudduha, but without proper monitoring, the UK risks mismanaging this hidden supply amid increasing development pressures.

Recent water outages in southern England, attributed to winter storms, have raised concerns about infrastructure resilience. Regulators have flagged serious issues with South East Water’s supply security. In response, the government released a water white paper aiming to overhaul the sector. Proposed measures include a new chief engineer role, “MOT-style checks” on infrastructure, and expanded regulatory powers to ensure long-term water security.

Experts warn that without urgent global action, cities will continue to face mounting water stress. With half of the world’s largest urban centres already experiencing high levels of scarcity, integrating climate-resilient infrastructure and sustainable management practices is critical. Failure to act now could leave billions exposed to unprecedented water insecurity, transforming daily life, agriculture, and industry in unpredictable ways.

The focus on water stress highlights the fragile balance between supply and demand, urging immediate attention from policymakers, businesses, and communities worldwide. Continuous monitoring, improved management, and investment in resilient infrastructure are essential to prevent a global water crisis. As urban populations grow and climate pressures intensify, water stress is no longer a distant risk but a present reality affecting millions.

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