The latest assessment found that 2025 was among the driest years for global river flows recorded over the past 35 years. River discharge remained below normal across 36 percent of the world’s river basin area.

It was also the seventh year in a row in which rivers showing historically normal flow conditions accounted for only a small share of global river systems. The trend highlights a water cycle that is becoming increasingly irregular and difficult to predict.

Water related extreme events continue to cause serious damage to communities and economies. Freshwater stored underground and on land, including groundwater, glaciers, snow, soil moisture and lakes, provides an important reserve during droughts and dry periods. These slower moving water resources can act like a savings account, helping communities manage temporary shortages.

However, this natural reserve is coming under increasing pressure. Terrestrial water storage has been declining since around 2014 to 2016, while groundwater levels have also dropped across many regions over a number of years.

Almost two thirds of monitored groundwater wells were outside their usual range in 2025. The overall trend showed more areas moving towards water deficits rather than recovery.

There were some areas of improvement. Parts of South America recorded a partial recovery in water storage following a severe deficit that had continued for several years. Central and southern Africa also recorded significantly above normal water levels across several major areas.

Glacier conditions remained a major concern. All 19 monitored glacier regions around the world experienced ice loss. Central Asia, Iceland, the Russian Arctic, western Canada and the United States recorded losses that ranked among their three most severe years on record.

Glaciers lost approximately 408 gigatonnes of ice during 2025 alone. Between 2023 and 2025, their combined losses reached around 1,400 gigatonnes. This amount is roughly equal to one third of the freshwater withdrawn globally in a single year.

Some areas with relatively small glaciers, including Central Europe, the Caucasus, western Canada and the United States, may already have reached a stage known as peak water. Once this point is passed, glaciers provide less meltwater each year because the amount of remaining ice continues to decline. This can have important consequences for communities that depend on glacier water during hot and dry summer months.

Further glacier loss cannot be completely avoided, but the eventual extent of that loss has not yet been fixed. Reducing emissions remains an important factor in limiting the scale of future glacier decline and protecting freshwater resources for communities that depend on them.