Global Reservoirs Threatened by Sediment Build-Up, Study Warns
Global Reservoirs Threatened by Sediment Build-Up, Study Warns
CN · Published Jun 9, 2026
A recent study led by Kai Liu from the Chinese Academy of Sciences has revealed that over half of the world's freshwater reservoirs could become 'functionally dead' by 2060 due to sediment accumulation. This phenomenon occurs as dams trap silt, sand, and gravel, reducing water storage capacity and impacting downstream ecosystems. The research analyzed over 550,000 reservoirs globally using satellite imagery, sedimentation data, and machine learning. The study estimates that more than 36 cubic kilometers of water storage is lost annually to sedimentation, equivalent to the volume of China's Three Gorges Reservoir. Countries like Australia and Spain are projected to be among the worst affected, with nearly 85% and 75% of their reservoirs, respectively, expected to exceed their functional lifespans by
The issue is particularly severe in arid regions, where nearly three-quarters of reservoirs may become non-functional, compared to half in humid zones.

Why It's Important?

The sedimentation crisis poses significant risks to global water security, threatening supplies for over 2 billion people and impacting more than a quarter of irrigated agricultural land. In regions like Namibia and Western Australia, over 95% of reservoirs are at risk of becoming functionally dead. The problem is exacerbated by climate change, which is expected to increase sedimentation rates due to intensified rainfall. Additionally, the loss of reservoir capacity could compromise dam safety and disrupt ecosystems reliant on downstream sediment flow. The economic and environmental costs of addressing this issue are substantial, with engineering solutions like dredging and bypass tunnels estimated to cost up to $100 billion.

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