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 levels in the unconsolidated aquifer reservoirs in the broad flood plains of the rivers Rhone, Aare, Ticino, Reuss, Limmat, Thur and Rhine are primarily characterised by infiltration from river water. Groundwater recharge in the unconsolidated and consolidated rock in other regions is formed predominantly from seepage of melt water or rainwater – dependent on the elevation. These variable recharge conditions cause typical seasonal fluctuations in groundwater levels and spring discharges, resulting in a groundwater regime characteristic of the region.

Current status

The status and trend of groundwater levels and spring discharges are nationwide continuously recorded at the NAQUA National Groundwater Monitoring groundwater wells and springs. They reflect the weather conditions on the surface, though in attenuated form and subject to a time delay. Long periods of precipitation – especially in winter – increase groundwater recharge. In contrast, sustained periods of drought can result in low groundwater levels and spring discharges.

Federal Office for the Environment FOEN: Current situation of the groundwater

Federal Office for the Environment FOEN: Groundwater bulletin

Trends

Long-term weather patterns (temperature and precipitation) in Switzerland are often correlated with periodic fluctuations in groundwater levels lasting for several years, entailing a regular succession of low and high water situations. Within this general pattern, significant regional differences are the norm.

In recent times, the dry years of 2011, 2015 and 2018 in particular led to low groundwater levels and spring discharges. On the other hand, years with above-average amounts of precipitation result in generally high groundwater levels and spring discharges (for ex. 1999 to 2002).