Rivers and lakes hit more than 30-year lows in 2025 as drought and flooding increasingly occur across different regions.
Rivers and lakes around the world reached their lowest levels in more than 30 years in 2025, according to the World Meteorological Organization (WMO). This was before Europe’s 2026 heatwave. Earth’s total amount of water remains unchanged, but its distribution between surface and underground stores, and between fresh and salt water, is shifting.
Melting glaciers and polar ice sheets send water into the oceans. It later evaporates and returns as precipitation, but winds and atmospheric currents distribute moisture unevenly. Africa had an especially dry year in 2025 while also experiencing floods, the WMO report says.
Climate change is intensifying these contrasts. Bettina Scheffler, a hydrologist at the University of Bern and president of the Swiss Academy of Sciences’ hydrology commission, says the most extreme years of the past two decades have occurred during this period. Regions that are already dry may become drier. Switzerland’s annual precipitation total may change little, but its seasonal distribution is becoming less even.
Thibault Datry of France’s INRAE institute describes the likely shift as stronger seasonality, with rainy periods followed by long dry spells. Water from floods cannot automatically be stored for future use. In mid-May 2026, rivers and groundwater in Switzerland and France still showed a surplus, he says, but conditions had become unusual only a few weeks later.
The changing water supply affects agriculture and industry and can raise tensions between countries. India and Pakistan dispute the management of dams and canals. Egypt and Ethiopia disagree over Nile water following construction of a major Ethiopian dam, which Cairo considers a threat to its water security.
Negotiations also involve Switzerland and its neighbours. Italy needs water to irrigate the Po Valley, prompting discussions over whether more water should be released. Scheffler says that five or six years ago countries in the region assumed there would be enough for everyone. Now they must coordinate how water is shared.