Unternavigation

State of groundwater

Groundwater is Switzerland's most important drinking water resource. In the past, the ability to extract sufficient quantities of high-quality groundwater has been taken for granted. However, groundwater resources are coming under increasing pressure. Residues of synthetic – and in most cases persistent – substances are adversely affecting groundwater quality. This has been demonstrated by analytical results of the NAQUA National Groundwater Monitoring.

Groundwater resources

Switzerland is rich in groundwater. Groundwater resources occur almost everywhere, both in unconsolidated sediments and fissured or karstified bedrock. They represent an important natural and economic resource.

Groundwater quantity

Groundwater levels and spring discharges indicate the status and trend of groundwater quantity conditions. Variations in groundwater quantity are heavily influenced by precipitation and temperature on the surface of the soil.

Groundwater quality

Groundwater does not naturally contain any persistent synthetic substances. Nitrate and residues of plant protection products have a long-lasting adverse impact on groundwater quality. Along watercourses, micropollutants from industry, commerce and households are also found in groundwater.

Groundwater temperature

To date, there has been no observable overall increase in groundwater temperature across Switzerland. In certain regions of the country, however, a slight rise in groundwater temperatures indicates the impact of climate change. For example, groundwater temperatures are rising by up to 0.06 °C per year in the Alpine region, in unconsolidated rock outside valley floors in the Central Plateau, and in the Jura. Direct human impacts on groundwater are also leading to measurable changes in groundwater temperature in densely populated areas.

Stable water isotopes

The stable water isotopes deuterium and oxygen-18 are natural tracers in the water cycle that can be used to determine the origin of water components and to track climatic changes.

NAQUA National Groundwater Monitoring

The NAQUA National Groundwater Monitoring provides a nationally representative picture of the situation and development of the groundwater resources in terms of both quality and quantity.