A recent study published in Nature Sustainability reveals that reservoirs globally are losing storage capacity at an average rate of 7.3% per decade, with small reservoirs being disproportionately affected. Led by Prof. Song Chunqiao from the Nanjing Institute of Geography and Limnology, the research utilized the Global REservoir Inventory (GREI) to assess over 550,000 reservoirs worldwide, of which over 95% are smaller than one square kilometer. These reservoirs are crucial for flood control, irrigation, and hydropower, but sediment accumulation is diminishing their capacity and threatening water security. The study found that nearly one in five reservoirs is already facing rapid storage loss, particularly in dryland areas like the southwestern United States and the Middle East. It also identified 16 global sedimentation hotspots, many in regions critical for agriculture. Alarmingly, about 25% of irrigated land is at risk, impacting over two billion people. The researchers warn that without effective management, more than half of the world’s reservoirs could degrade by 2060, emphasizing the need for sustainable practices to ensure long-term water, food, and energy security.