Climate change: what can be done to prevent drying up of streams?

Status: 08/26/2022 06:36 AM

Drought streams are a growing problem in Germany. They are also dangerous to animals that live in water bodies. What can be done about it?

Lumps of dead trout, balsams, and kadders were discovered two weeks ago in the dry stream of the Graefenbach River. You won’t soon forget this sight in the small community of Gothenburg near Bad Kreuznach.

“It terrified me,” says Jens Wichmann of the Bad Kreuznach fishing club. Responsible for the fact that Gräfenbach completely ran out of water in some places is not only drought and heat, but also residents illegally sucking water for their private gardens, Wichmann criticizes. This pumping has exacerbated the already tense water situation in the creek.

Hans-Jürgen Hahn of the University of Koblenz-Landau warns of the devastating consequences for the ecosystem.

Photo: SWR

Currents that become streams

Currents turning into streams or disappearing completely is a phenomenon that experts believe is increasing in Germany. “This is due to a lack of precipitation, but also due to lower groundwater levels, and both flow,” explains Hans-Jürgen Hahn of the University of Koblenz-Landau. There are many regions in Germany, such as the Upper Rhine Graben, Middle Franconia or Brandenburg, where this takes on critical proportions.

There, the bodies of water do not get enough water to replenish themselves, neither from above nor from below. On the one hand, due to less rainfall there, and on the other hand, less and less groundwater is produced as a result of climate change. If the groundwater level is too low, it can no longer pressurize the streams and supply them with adequate water.

There are no isolated cases.

“These are not isolated cases, but due to climate change, more and more water bodies are expected to dry out in the future,” warns aquatic ecologist Han. With severe consequences for the ecosystem. Because the less water, the more dangerous the conditions for threatening organisms: “Because of the combination of heat and lack of oxygen in the water, the animals there are at risk of suffocation.”

Fishing enthusiasts worry

Guldenbach flows a few kilometers from the Gutenberg municipality of Guldental. Here, too, the situation is tense. The water level is 1-2 cm in many places these days, 20 cm is normal. Of course they know the terrible pictures of dead fish in Gravenbach. That is why members of the Guldental Fishing Club regularly check the water temperature.

warm water

Dennis Hoeing and Jürgen Hess read 21 degrees of the thermometer they dived into in Goldenbach at a point where many small fish are currently swimming. “Fortunately, the temperature didn’t rise any more,” Höning says relieved. “The temperature is really stressful for the trout and salmon we have here in the stream,” Hess says. “But at 24 degrees, the ecosystem is gone.”

natural rings

Hunters are worried about Guldenbach, but at the same time they are convinced that it could be much worse. They point to the positive effects of their years of renovation efforts. In some areas, the fishing club has removed bank structures, such as river and masonry stones, so that the stream can take its original course again. The current can form natural loops in this area again.

In the course of the river itself there are also deep depressions in places where cold water collects, which is a haven for fish. “These are deeper areas, with a depth of 1.50 to two metres. This is where fish and creatures can withdraw very well.”

Rehabilitation grants

Explaining successful re-saturation measures, financed by subsidies, among other things, Jürgen Hess points out to Guldenbach: “Currently brown trout are hidden under the roots, which means they are looking for a great hiding place there.” The Guldental Fishing Club also frequently planted trees near the shore. They provide shade to the stream and thus ease the heating of the water.

In Hahn’s opinion, such measures have an exemplary character, and an aquatic ecologist from the University of Koblenz-Landau calls for more commitment on the part of politicians. For the researcher, one thing is certain: measures taken only in the immediate vicinity of water bodies are not enough.

More measures planned

“We have to keep more water in the area, that is, everywhere in the landscape, which has a positive effect on the water level in the rivers and streams that benefit from it.” To do this, Han explains, the landscape as a whole must be an ecological re-enactment, for example by planting more hedges and trees, but also by installing basins to trap rainwater and expose urban areas.

At Guldental, the hunting club is planning more rehab action this fall. Here, too, more attention is needed on the part of the population living near the creek. For hoses and pumps were also discovered in Guldenbach, where the inhabitants watered their gardens.

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