Successful renaturation of the Dreisam: fish population explodes!

Successful renaturation of the Dreisam: fish population explodes!

The renaturation of a section of the Dreisam near Nimburg, in the Emmendingen district, has now been completed. With a budget of around 30,000 euros, an approximately 700 meter long section of the river was redesigned. The aim of these measures is to improve the habitat for fish and other aquatic creatures, which should also increase local biodiversity. This initiative ensures that cold groundwater with temperatures of around 12 degrees seeps into the riverbed, which is a condition for survival for many species. Excavators created several fish pools with a depth of up to 1.60 meters, which offer a place suitable for life even at low water levels.

To ensure flood protection, protective walls made of tree trunks placed in a V-shape were also built. These tree trunks cause water turbulence and increase the oxygen content in the water, which is vital for the aquatic ecosystem. In addition, the large root system of the trees provides shade and protects the fish from predators. Before and after the renaturation, experts examined the fish stocks: the population more than doubled from around 1,100 to over 2,500 fish, while the number of species increased from 11 to 14. Bernd Walser, the river master of the Freiburg regional council, emphasized that this project was a real success. He hopes that the experience gained can be used as a blueprint for similar projects on other rivers, according to [SWR](https://www.swr.de/swraktuell/baden-wuerttemberg/suedbaden/renaturierung-dreisam-kaelte Becken-fuer-fische-nimburg-bei-freiburg-100.html).

Background to the renaturation

The renaturation of the Dreisam is part of a larger initiative aimed at revitalizing aquatic habitats in Germany. Although the term “renaturation” is used, in many cases it is more correct to speak of “revitalizations”. A complete return of the Dreisam to its original state is not possible due to the heavy construction. Instead, the measures implemented aim to make the rivers more natural. These projects are not only important for the flora and fauna, but also help to reduce flood risks and increase the quality of life in cities and rural areas, as can be found on the Umweltbundesamt.

The Dreisam interest group emphasizes that the cooperation of numerous organizations as well as municipal and state departments is necessary in order to successfully implement such projects. It is important to protect ecological watercourses from harmful human interference. The spectrum of possible measures ranges from the removal of hard bank reinforcements to the reconnection of oxbow lakes so that the water bodies can regenerate themselves. One goal is for the aquatic habitats to take on an even stronger ecological function and to be able to better withstand the challenges of climate change.

Outlook and meaning

The successes of the renaturation of the Dreisam could set a precedent. Projects like this are crucial to protecting nature and promoting biodiversity. In times of climate change, the creation of natural habitats becomes a central task - both for the environment and for the people who outgrow their living environment. The knowledge gained should help to implement similar measures sustainably and thus have a good hand in water design elsewhere in the country.

The online platform “Renaturation of Rivers” offers valuable information and support for people who are interested in sustainable planning and implementation. Intact flowing waters are more than just watercourses - they are habitats that are equally important for people and the environment, as IG Dreisam emphasizes.