The planet is exhausting its fresh water reserves

BarcelonaThe planet has been spending its freshwater reserves for a decade. This is warned by the report on the state of global water resources from the World Meteorological Organization (WMO), published this Thursday. The study concludes that the storage of continental water – in groundwater, rivers, lakes, soil, vegetation, snow, and ice – has maintained a downward trend since the 2014-2016 period. And it is not just a question of drought: the water cycle is becoming increasingly irregular, with alternating periods of lack and excess.

“We are spending our reserves,” explained the WMO Secretary-General, Celeste Saulo, at the presentation of the report. According to the organization, slow reserves – groundwater, glaciers, and seasonal snow – functioned as a “savings account” for the planet: they accumulated water for years and acted as a buffer against droughts. Now, this safety margin is also shrinking. Almost two-thirds of the wells monitored around the world showed conditions outside their historical normality in 2025.

2025 was, moreover, one of the driest years for river flows in the last 35 years. 36% of the surface of global river basins recorded flows below normal. For the seventh consecutive year, basins with flows considered normal were in the minority: between 34% and 38%, below the average of 46% for the 1991-2020 period. "The anomalous is becoming the new normal," points out Wayne Jenkinson, Director of Hydrology and Cryosphere at the WMO.

One of the most visible signs is the retreat of glaciers. 2025 was the fourth consecutive year with widespread ice losses in all major glacial regions of the planet. Last year alone, 408 gigatons of mass were lost, equivalent to a 1.1 millimeter rise in sea level. And between 2023 and 2025, the cumulative loss reached 1,400 gigatons of water, equivalent to about 560 million Olympic swimming pools.

The report also shows that water scarcity is not uniform and experiences increasingly extreme episodes due to the climate crisis, with extraordinary droughts in some regions and extreme floods in others.

All of this is causing an increasing number of fatalities. Asia and Africa have accounted for half of the world's extreme water-related events over the last five years and more than 80% of the associated deaths. And in some territories, the interval between a flood and a drought no longer leaves enough time for recovery. Faced with this scenario, the organization calls for shared data, common standards, and early warning systems.

The effects at home

In recent years we have seen these climate extremes increase in our country, with increasingly torrential rains, historic heat waves and extraordinary droughts. “The rainfall regime is changing and the so-called flash droughts, short-lived (2 or 3 months), but very intense and with high temperature values that increase water evaporation, are becoming more frequent; that is what has happened in a large part of Europe this summer”, says Jorge Olcina, professor of Regional Geographical Analysis at the University of Alicante.

In this sense, Olcina warns that areas such as the Pyrenees or the Cantabrian region are the “least prepared” for these episodes of short-term droughts with extreme heat like the ones we have experienced in recent months, as they are areas with regular and abundant rainfall. “They do not have urban supply systems prepared for this new climatic reality”, he states.