Full Breakdown
2025 Marks One of the Driest Years for Global Rivers
By Drooid · · How we work
Key Findings of the WMO Assessment
The World Meteorological Organisation’s (WMO) latest global water-cycle assessment shows that freshwater stored on land and underground was 42 % below normal in 2025. Only about one-third of river basins recorded flows within the historical “normal” range, while 36 % fell below or far below normal and 21 % exceeded normal levels. The study, which synthesised simulations from 13 hydrological models driven by observed weather, also recorded the fourth consecutive year of ice-mass loss across all 19 major glacial regions, with 400 gigatons of ice lost in 2025 alone—contributing roughly 1.1 mm to global sea level rise. Repeated below-normal flows were observed in major basins such as the Amazon, La Plata, North America, central and east Africa, central Asia and the Middle East.
Implications for Human Systems
The decline in river flows has already translated into tangible crises. In the summer of 2025, record-low water levels on the Danube forced the shutdown of all but one nuclear reactor in Hungary and Romania, triggering an energy shortfall. In the United States, the Mississippi River—primary water source for 50 municipalities—faces compounded threats from chemical pollution, hypoxic dead zones in the Gulf of Mexico, sea-level-driven wetland loss and intermittent droughts. African rivers including the Nile, Niger and Zambezi are experiencing severe pollution and climate-induced droughts that jeopardise local ecosystems and livelihoods. In England, no river meets overall ecological and chemical health standards, suffering from sewage, agricultural runoff, “forever chemicals” and over-abstraction.
Official Statements & Responses
Celeste Saulo, secretary general of the WMO, warned that the planet’s “savings account” of terrestrial water is being depleted, noting a persistent decline in storage since 2014-16. Wayne Jenkinson, director of hydrology at the WMO, called the research a “call to action,” urging expanded data collection and sharing to improve global water-resource understanding and protection for people’s lives and wellbeing.
Verbatim Quotes
- “We are depleting that savings account. Global terrestrial water storage has shown a declining trend since 2014–16 – a persistent, decade-long signal.” — Celeste Saulo, secretary general of the WMO