Thuringia: droughts depress groundwater levels: danger for supply?

The droughts of recent years have affected the groundwater in many places.

Thuringia: droughts depress groundwater levels: danger for supply?

The droughts of recent years have affected the groundwater in many places. But the majority of the drinking water supply in Thuringia depends on it. In the long term, there is hardly any improvement in sight due to climate change - on the contrary.

Jena (dpa/th) - The groundwater level in Thuringia has not yet recovered from the drought in summer. The precipitation of the past few months would not have been enough to compensate for previous deficits, said Stefan Brune, head of the climate competence center in the State Office for the Environment, Mining and Nature Conservation, the German Press Agency.

The level is very low at around half of the groundwater measuring points. Long periods of drought had previously affected the groundwater in 2018, 2019 and 2020. Regionally, the Thuringian Basin and regions of eastern Thuringia are particularly affected. More than half of the drinking water supply in Thuringia is fed from groundwater.

Basically, the groundwater levels fluctuated, the expert emphasized. Typically, falls in summer would be offset by precipitation in fall and winter. It also depends on the type of precipitation. Persistent land rain is better for the groundwater than heavy rain, which mainly drains off the surface. Even a closed blanket of snow that is constantly thawing favors the groundwater level in the long term.

In addition to precipitation, there are also other environmental influences on the groundwater. "The soil under intact forests has an important filter and buffer function," explained Brune. The dying of entire forest areas due to bark beetles and extreme drought have therefore recently also had a negative impact on the groundwater in some regions of Thuringia.

As a result of man-made climate change, experts expect an increase in extreme weather events and warmer winters, so that the problems for the groundwater in Thuringia are likely to increase. The Ministry of the Environment therefore presented a low-water strategy last year.

It says that there have been years with extremely low groundwater levels in the past. "However, it is also evident that in the past decade there has been an increasing tendency for low groundwater levels to be observed for several years in a row. Years with predominantly high groundwater levels, on the other hand, only occurred occasionally."

In order to secure the drinking water supply in Thuringia, a stress test is therefore planned in coordination with the municipal water suppliers. Provisions for the future should be derived from this.

According to Brune, individual wells have dried up in some places in the past or there have been quality problems with nitrate and salinity, for example. "These are effects that we are already seeing." In order to ensure the water supply everywhere, the connection of affected places to the long-distance water supply is an option. It is fed from the drinking water reservoirs. It should also be considered to network supply areas more closely.