Salinization of coastal groundwaters in the EU – What can we do about it?

Salinization of coastal groundwaters in the EU – What can we do about it? Written as part of the LIFE-FRESHMAN project, this article examines the issue of coastal groundwater salinization in the EU, particularly its impact on freshwater reserves, and highlights key strategies for mitigation. Coastal zones across Europe rely on fresh groundwater reserves for drinking water production, agriculture, and industry. In the mid to high-latitude regions, freshwater use is primarily urban and industrial, whereas irrigation and tourism dominate seasonal water demand in the Mediterranean area (Custodio, 2009). These fresh groundwater reserves depend on rainfall or additional artificial recharge using local fresh surface water resources, such as rivers and lakes (MAR; managed aquifer recharge). Overexploitation of coastal groundwater results in the salinization of these aquifers (Figure 1; Van de Wal et al., 2024), often leading to the abandonment of groundwater extraction wells. As coastal urban areas continue to experience rapid population growth and economic development, freshwater demands are only increasing (Vörösmarty et al., 2000). Meanwhile, saltwater intrusion is further amplified by climate change through changes in natural recharge patterns and sea-level rise (Portmann et al., 2013; Zamrsky et al., 2024).