Croatia’s groundwater remains among Europe’s best preserved, new report finds

New report shows Croatia’s groundwater remains in excellent condition

ZAGREB, 1 July 2026 (Hina) – The Josip Juraj Strossmayer Water Institute published its 2025 Water Status Report on Monday, showing that no exceedances of groundwater quality standards were recorded at 95% of monitoring stations.

“The results confirm that groundwater remains the best-preserved component of Croatia’s aquatic environment. At around 95% of monitoring sites, no breaches of prescribed groundwater quality standards were identified,” the Institute said.

The report is based on monitoring carried out at more than 900 stations covering rivers, lakes, groundwater, transitional and coastal waters, and it is used to assess water resources and plan protection measures.

The Institute added that very strict criteria were applied when assessing the chemical status of groundwater bodies, meaning even a single exceedance at one station could affect the classification of an entire water body.

“The key message is that, compared with previous reporting periods, no significant changes in overall water quality trends in Croatia have been observed. This is not a reason for complacency, but a confirmation that water protection must be viewed as a permanent process. Monitoring shows where we are today, while investment in water protection determines the state tomorrow,” said Institute director Mario Šiljeg.

For rivers and lakes, the main challenges are linked to preserving natural river ecosystems.

Over decades, many waterways have been regulated, dammed or altered for flood protection, energy production, navigation and other uses. These changes affect natural river flows, habitats and biodiversity, making restoration a key condition for long-term conservation, the Institute noted.

For transitional and coastal waters, which include river estuaries and nearshore sea areas, most remain in good or very good ecological condition.

“The findings of Croatian monitoring are consistent with European reports, which identify climate change, altered river ecosystems, diffuse pollution sources and persistent priority substances as key challenges,” it was said.

The report also stresses the importance of continued investment in wastewater collection and treatment systems, reducing pollution at source and restoring waterways using nature-based solutions.