Climate crisis: Groundwater in Hesse: Still a significant deficit

The groundwater situation in Hesse has eased since the summer of 2022.

Climate crisis: Groundwater in Hesse: Still a significant deficit

The groundwater situation in Hesse has eased since the summer of 2022. But according to a report by the Hessian State Office for Nature Conservation, Environment and Geology (HLNUG), the groundwater level that is usual for this time of year is still well below that at many measuring points. "There is still a significant deficit in groundwater," explains the authority.

The proportion of measuring points with below-average and very low groundwater levels has fallen continuously since September 2022. "At the same time, the number of measuring points with below-average and average groundwater levels has increased."

The wet March should therefore bring some relief, even if this will probably only become more noticeable in the coming weeks due to the delayed reaction in the groundwater. According to HLNUG, it rained an average of 111 liters per square meter across Hesse last month. This corresponds to more than twice the mean total precipitation for March in the reference period from 1991 to 2020 of 54.6 liters per square meter.

According to HLNUG, around 80 percent of the measuring points were registered at the turn of the month, some of which were significantly rising groundwater levels. In many measuring points, however, the effects would only become noticeable in the course of April or later. "It can be assumed that the increases in April will continue and will ensure further relaxation in the groundwater."

In March, a quarter of the measuring points showed groundwater levels at a very low level, around 20 percent below average values. According to HLNUG, average levels were observed at 44 percent of the measuring points, above-average or very high only at five or four percent of the measuring points. Compared to the previous year, the values ​​in March at 55 percent of the measuring points were lower than a year ago.

"The current groundwater situation in Hesse is not only due to the dry weather conditions in 2022, but essentially to the high precipitation deficit of the extremely dry year 2018 and the dry years that followed, 2019 and 2020," explains the HLNUG. With increasing climate change, precipitation will fall more frequently in the form of short-term heavy rain events and less frequently in the form of so-called land rain. "This also causes longer periods of drought, especially in summer."

In addition, it is clear that climate change will undoubtedly make it warmer. "As a result, the vegetation period during which plants withdraw water from the soil to grow is lengthened. The higher temperatures also lead to more evaporation from the plants per day." The climate change that has already occurred is thus increasingly causing water shortages. "As climate change progresses, these situations will become more frequent and worse," warns the HLNUG.

"The massive effects of climate change on the water balance in Hesse have been obvious since the drought summer of 2018," says Thomas Norgall, nature conservation officer and deputy managing director of the Hessian Federation for the Environment and Nature Conservation Germany (BUND Hessen). Water policy is becoming more important from year to year and the necessary course must finally be set in the next legislative period.

"The decisions to secure the drinking water supply and to save the forests in the Rhine-Main area are overdue," emphasizes Norgall. "Without a significant increase in groundwater levels and groundwater recharge in the water catchment areas in the Hessian Ried and in the Frankfurt area, as well as a consistent water-saving policy in connection with the groundwater tax as a steering instrument, the problems will continue to grow and the solutions to the problems will become significantly more expensive." Anyone who wants to save the forests and ensure prosperity in the Rhine-Main area must have the courage to act.