Global Rivers Recorded One of Their Driest Years in More Than Three Decades
Global Water Resources: The world’s freshwater systems faced another year of significant pressure in 2025, with global river discharge reaching one of its lowest levels in more than three decades, according to a newly released assessment of the planet’s water resources.
The report found that 2025 was among the driest years for global river flows in the past 35 years. Below-normal river discharge affected approximately 36% of the world’s river-basin area, highlighting major differences in water availability across regions.
River Flows Remain Highly Unusual
The latest assessment shows that normal river conditions have become increasingly uncommon. For the seventh consecutive year, only around 34% to 38% of river basins recorded normal conditions, compared with an average of about 46% during 1991–2020.
The findings indicate that the global water cycle is becoming increasingly variable, with some regions experiencing severe shortages while others face excessive rainfall and flooding.
Water Storage Has Declined
The report also identifies a continuing decline in water stored across the world’s land surface. Terrestrial water storage—including groundwater, lakes, rivers, soil moisture, vegetation, snow and ice—has shown a negative trend since the middle of the 2010s.
Persistent below-normal water storage was reported in several regions, including parts of North America, the Middle East, Central Asia, eastern China and northern India.
Glacier Loss Continues
Glaciers also remained under pressure in 2025. It was the fourth consecutive year in which every major glaciated region recorded a net loss of ice.
During the 2025 hydrological year, glaciers lost an estimated 408 gigatonnes of mass, equivalent to approximately 1.1 millimetres of sea-level rise.
The continued loss of glacier ice has implications for both short-term hazards and long-term water availability, particularly for communities that depend on glacier-fed rivers.
Asia and Africa Face Major Water Risks
Asia and Africa were identified as the regions most affected by water-related extreme events. Together, they accounted for at least half of recorded water-related extreme events and more than 80% of reported associated deaths over the five-year period covered by the assessment.
The report also notes that hydrological observation networks remain less developed in parts of Asia and Africa, despite these regions experiencing some of the greatest impacts from water-related extremes.
Groundwater Also Shows Signs of Stress
Groundwater conditions provided another warning signal. Persistent groundwater deficits were observed in several parts of the world, including areas of India, Europe, the Middle East, Africa and the Americas.
The assessment found that nearly two-thirds of monitored wells worldwide were outside their historical range during 2025, with conditions shifting further toward deficit compared with the previous year.
Growing Importance of Water Monitoring
The latest findings underline the importance of reliable hydrological observations, satellite measurements and international data sharing. The assessment combines information from national services, global hydrological models and satellite observations to examine river flows, groundwater, water storage, snow, glaciers and extreme events.
With water conditions becoming increasingly variable across different parts of the world, regular monitoring is becoming increasingly important for water management, disaster preparedness and long-term planning.
