River salinisation in Europe: about half of the river network affected, more than 23,000 km above 1 mS/cm
On 21 August 2026 the European Commission’s Joint Research Centre (JRC) presented a study published in Nature Communications: based on the electrical conductivity of water from 35 countries, about half of the European river network is affected by salinisation, and more than 23,000 km (about 2 %) exceed 1 mS/cm — above international standards for the protection of aquatic life.
- Salinity was assessed through electrical conductivity (mS/cm), a widely used proxy for salt concentrations in freshwater; data come from the GlobSalt database, which combines records of conductivity, major ions, organic matter and nutrients from 62 public sources (including the EEA’s Waterbase) for 1970–2024.
- In 28 of the 35 countries there are rivers where salinity has more than doubled compared with estimated natural background conditions. According to the JRC, 26 % of the network shows low, 14 % moderate, 9 % severe and 1 % extreme salinisation; drinking water limits are exceeded in about 1 % of the network, and irrigation and industrial water limits in about 3 %.
- Well-documented hotspots include Germany, Poland and Spain, while previously underreported hotspots were identified in Romania and Hungary. According to the article, the highest salinisation values, up to 9683 µS/cm, were recorded in catchments in Germany and Poland; the Oder is among the well-studied cases the authors cite.
- The JRC notes that 25 years after the adoption of the Water Framework Directive most countries still lack dedicated salinity standards and do not systematically monitor its impacts; the authors call for Europe-wide salinisation standards aligned with the directive.
Source: Joint Research Centre — River salinisation is widespread across Europe (21.08.2026)