GNV News May 31, 2026

A study published in the scientific journal Nature Water in April 2026 has revealed that the risk of seawater infiltrating groundwater—known as “saltwater intrusion”—is spreading in coastal regions around the world.

Based on groundwater monitoring data from approximately 480,000 locations worldwide over a period of 34 years, from 1990 to 2024, this study systematically analyzed on a global scale the relationship between declining groundwater levels in coastal areas and saltwater intrusion.

About half of the world’s drinking water and about one-quarter of irrigation water are supplied from groundwater. However, the study found that groundwater levels have markedly declined at more than 10% of the surveyed locations, making it clear that water use in these areas could become impossible due to salinization. At the same time, sea-level rise driven by climate change is making it harder in some places to curb saltwater intrusion. The paper’s authors note that, because groundwater is hidden underground, the crisis has a structure that makes it “hard to see.”

The large-scale monitoring data, however, clearly show that groundwater is in crisis. The study points out that the risks are particularly high in arid regions, large-scale agricultural areas, and densely populated regions. At the same time, it acknowledges a limitation: the available data are biased toward temperate regions such as Europe and the United States, while data from Africa, equatorial regions, and much of South America and Asia remain insufficient.

Prior to the publication of this paper, a BBC article in February 2026 also highlighted the spread of this problem around the world, presenting individual cases in Gambia, the United States, Vietnam, and elsewhere, and describing the current situation facing farmers.

In its conclusion, the paper stresses the need for strengthened monitoring and integration of observational data in order to respond early to the risks of saltwater intrusion.

The Maldives are impacted seawater intrusion are being supported (Photo: IWRM AIO SIDS / Flickr [CC BY-NC-ND 2.0])