Groundwater

Switzerland has very large groundwater resources but with a heterogeneous spatial distribution. This is why more local, temporary deficits in groundwater availability are already occurring during drought. This trend will increase due to climate change. Groundwater recharge will increase in winter and spring and decrease in summer and autumn.

Groundwater is the largest and most important water storage resource in Switzerland. A distinction is made between groundwater in unconsolidated rock, fractured rock and karstic limestone. Its total volume is estimated at 150 km³, but the sources vary in abundance. More local, temporary deficits in groundwater availability are already occurring during drought. This trend will increase due to climate change.

Outline map of the abundance of groundwater resources in Switzerland

The very abundant groundwater resources are found mainly in the unconsolidated rock aquifers in the river valleys.
© Sinreich et al. (2012)

As a result of the expected increase in winter precipitation, the higher rain contribution and the earlier snow melt, groundwater recharge will increase in winter and early spring at all elevations. In higher regions this factor will be reinforced because the ground will be frozen or covered with snow for a shorter period in the wintertime.

Groundwater recharge will decrease in the summer, however, owing to lower precipitation and greater evaporation. This applies particularly in Alpine river valleys, where declining snow and glacier melt in the summertime will be noticeable.

A slight decrease in groundwater recharge is expected over the course of the year as a whole. But as long as the total groundwater recharge is sufficient to fill the aquifers over several years, little will change in relation to the total resource volume, even with climate change. The change in recharge does however affect the seasonal distribution of groundwater levels and thus its sustainably usable volume.

Groundwater recharge and influencing factors due to climate change

How much groundwater is recharged from river water or precipitation depends on the nature of the catchment. The amount varies according to the season and the elevation of the regions concerned. As climate change progresses, groundwater recharge will increase in winter and early spring at all elevations and decrease in summer and autumn.
© Hunkeler et al. (2020)

Documents

The report ‘Effects of climate change on Swiss waters’ gives a concise overview of the results and is a gateway to further technical information and data.

Links

Last modification 12.05.2021