WaterAid has released new data revealing the escalating global crisis of water-related disasters. From intensifying droughts to catastrophic flooding, urban populations worldwide are facing mounting threats to clean water access.
New WaterAid research, published in March 2025, reveals which of the world’s 100 most populated cities are becoming increasingly exposed to floods and droughts – risking the security and survival of communities around the world.
The report ‘Water and Climate: Rising Risks for Urban Populations’ unveils which cities across Africa and Asia are emerging as the most at-risk to extreme climate shifts worldwide, which is having devastating impacts on access to clean water for urban communities on the frontline of climate change.
Almost 1 in 5 (17%) of the cities studied emerge as experiencing ‘climate whiplash’ – which involves intensification of both droughts and floods – whereas 20% of cities have seen a major flip from one extreme to the other.
Cities in Southern Asia are becoming overwhelmingly flood-prone and European cities are exhibiting significant drying trends, all of which can impact people’s clean water access and water security.
From recent drought in cities like Madrid (Spain) and Cape Town (South Africa), to large-scale flooding across cities in Bangladesh and Pakistan, 90% of all climate disasters are driven by too little or too much water.
WaterAid, the world’s leading water, sanitation and hygiene charity, warns that weather-related disasters such as flooding and drought have increased by 400% in the last 50 years, putting major pressure on vital water access and sanitation systems and making it harder for communities and economies to prepare for, recover from and adapt to climate change.
The pioneering new study, developed with academics from University of Bristol and Cardiff University, compares each city’s social and water infrastructure vulnerabilities alongside 40+ years-worth of data on climate hazards – concluding which cities and communities worldwide are the most vulnerable to extreme climate changes and the least equipped to handle them.
And it is not just highly populated cities facing the extremes of climate change. The Pacific Islands are some of the least responsible, yet most affected when it comes to climate change.
Collectively, The Pacific Islands account for less than 0.03% of global greenhouse gas emissions, yet they are among the most vulnerable to the impacts of climate change.
Coastal erosion, saltwater intrusion into freshwater supplies and more frequent and severe cyclones threaten homes, health and futures.
Rising sea levels are contaminating water sources with saltwater, rendering traditional sanitation systems ineffective.
Flooding and extreme rainfall events overwhelm toilets, causing contamination of communities' water supplies and spreading diseases like cholera and diarrhoea.
The vulnerabilities the report examines range from poverty to poor water and waste systems – exposing ever-expanding urban populations at risk to intensifying floods or droughts, leading to displacement, instability and loss of life.
Severe urban flooding can damage sanitation facilities, spreading diseases such as cholera and typhoid, whilst water shortages during droughts are leaving millions of families without the water they need to survive.
Top report findings include:
Meanwhile in Europe, cities like Madrid and Paris are exhibiting significant drying trends, with Europe’s older infrastructure also putting many cities at increased risk of vulnerability to extreme weather, the new data reveals.
Tom Muller, WaterAid Australia’s Chief Executive, said: "With 90% of all climate disasters driven by too little or too much water, there is an urgent need for governments around the world to recognise the importance of investing in long-term plans to manage water resources and guarantee access to drinking water.”
"Unfortunately, this research comes at an incredibly pivotal time, as globally we are seeing sweeping cuts to overseas aid, which undermines our collective ability to respond to the impacts of climate change.
"Highlighting an increase in climate whiplash across global cities – with the impact felt most clearly in low-income countries, but with global implications – the report is a reminder that now more than ever, Australia needs to continue to be at the forefront of global efforts to address climate change."
WaterAid is working with partners globally to make sure people have the water they need to adapt to the impacts of our changing climate – including in some urban and peri-urban settings.
The solutions can be simple: harvesting rainwater to provide clean and safe water through drought; monitoring water levels so communities can prepare for extreme weather; installing toilets designed to withstand floods and keep water sources clean.
But the organisation warns it is not the role of civil society alone to solve these issues and is calling on global decision makers to prioritise and invest in these key solutions that strengthen community resilience against extreme weather – to protect livelihoods, save lives, and strengthen global security in a turbulent world.
Tom Muller added: "Now is the time for urgent collective action from global leaders, multilateral banks and the private sector to unlock investment so that communities can recover from disasters, stay healthy, and be ready for whatever the future holds. This will make the world a safer place for all. It all starts with clean water.”
WaterAid is calling for:
Global leadership to accelerate action on water – Governments and development partners must work through the existing multilateral platforms to deliver ambitious action on climate and water, including through the UNFCCC, the G7 Water Coalition and the G20 Call to Action on Strengthening Drinking-water, Sanitation, and Hygiene Services.
National government leadership to urgently deliver water plans – Governments in affected countries to mainstream and implement water, sanitation and hygiene measures into their national and city-level climate adaptation plans with a focus on vulnerable groups, especially women and girls.
Prioritise the most vulnerable communities – All decision-makers to recognise overlapping vulnerabilities and prioritise the leadership and needs of women, girls and marginalised groups in climate-resilient water, sanitation, and hygiene plans.
Professor Katerina Michaelides, Lead Scientist from University of Bristol, said: “The findings from our study illustrate just how differently and dramatically climate change is expressing around the globe – there is no one-size-fits-all."
"Places that were historically wet are becoming dry and vice versa. Other places are now increasingly battered by both extreme floods and droughts. A deeper understanding of localised climate hazards and the changing global water cycle can support more intelligent and bespoke planning in major cities.”
Professor Michael Singer, Lead Scientist from Cardiff University, added: “One interesting outcome of this study is how many of the climate hazard trends appear to spread over broad regions, suggesting that there may be significant adaptation challenges to new hazard regimes, but also regional opportunities for collaboration between nations to become more resilient to the climate and water crisis in urban centres.”
This article was originally published by WaterAid. You can find the original here.