![[Translate to English:] Forschende um Prof. Dr. Bernd Cyffka (Leiter des Aueninstituts Neuburger der KU; rechts im Bild) dokumentieren und erforschen seit 15 Jahren, welche Folgen die Renaturierung von Auwäldern an der Donau hat. Diese Expertise bringen sie nun bei einem neuen Projekt am Lech ein.](/fileadmin/_processed_/0/a/csm_Aueninstitut01a_142380d6e0.webp)
The pilot project aims to work out how the effects of climate change on rivers can be reduced and how CO2-free electricity generation from hydropower can be reconciled with the interests of water and floodplain ecology. Various municipalities and associations are cooperating under the leadership of LEW Wasserkraft GmbH. Scientific partners are the University of Augsburg, the Technical University of Munich and the Floodplain Institute Neuburg-Ingolstadt, a research center of the KU.
The focus is on rivers with diversion power plants; the Lech north of Augsburg is the specific object of research. Over 100 years ago, a canal was created to generate electricity, which runs parallel to the Lech and is fed by its water. It branches off at Gersthofen, carries the water over a total length of around 20 kilometers past three power plants, where it is used by LEW to generate climate-friendly electricity, and flows back into the Lech in Meitingen. Only a small amount of residual water remains in the main river channel of the Lech, which warms up quickly. This problem will become more acute in the coming years: Due to climate change, according to experts lower water levels and higher water temperatures are to be expected in European rivers. This has serious consequences for the ecosystem, as many native fish species such as brown trout and grayling are dependent on cold, oxygen-rich water.
The aim of ConTempO2 is to actively control the temperature and oxygen content of the water and thus keep it within a range that is not critical for the ecosystem. In addition, the floodplains are to be made more resilient to the consequences of climate change. "Floodplains in general are facing massive problems due to climate change", says Sebastian Blaß, project member of the Floodplain Institute at ConTempO2. The direct connection to the water is very often interrupted: "Smaller bodies of water that still bring water into the floodplain are increasingly drying up, meaning that valuable habitats and rare species are being lost." In the case of the Lech, too, the problem is that there is very little water left in the floodplains. However, regular and planned flooding contradicts the intensive use of water bodies by humans, for example through hydropower.
As part of ConTempO2 , water is to be fed from the Lech canal into the riparian forests at several points via special channels. As Blaß emphasizes, the water is deliberately taken from the Lech canal and not from the original Lech riverbed: "This will not change the sensitive ecosystem in the Lech itself, but the water can be used to generate energy for as long as possible." The Floodplain Institute supports the reconnection and revitalization of the floodplain areas and, in particular, is responsible for the scientific monitoring of the floodplain vegetation. What effect does reconnecting a river with the adjacent riparian forest have on the flora and fauna? And what kind of dynamics do bodies of water develop within the riparian forest? The Floodplain Institute has many years of expertise on these issues.
For 15 years, the research team led by Institute Director Prof. Dr. Bernd Cyffka has been investigating the long-term effects of renaturation measures on the Danube between Neuburg and Ingolstadt. An eight-kilometer-long natural bypass was created within the remaining riparian forest. So-called "controlled flooding" is also being effected via new diversion points in the Danube embankment, which is intended to restore the forest to a nature-like riparian forest. The studies carried out by the Floodplain Institute on the Danube show that it takes time for nature to reclaim the riparian forest. Bird and fish species returned soon after the first floods, beetles and other insects with a time delay. The lower the mobility of the species, the longer it takes for positive developments to be observed. With trees, this is therefore a particularly long process.
An important pillar of renaturation processes in general and the ConTempO2 project in particular is the involvement of the local population, municipalities, authorities and associations. "Many of the areas we work with in ConTempO2 are located in two valuable flora-fauna-habitat conservation areas. Comprehensive cooperation with all local players is therefore of crucial importance", explains Sebastian Blaß. In addition to ensuring sustainable energy generation and strengthening the river ecology, the social function of the Lech as a local recreation area and place of environmental education is a declared aim of the project. In order to reconcile energy generation from hydropower and environmental protection, a dynamic management approach will be developed by 2027, which can also be used to react flexibly to local conditions. The findings from the project will then be transferred to comparable rivers with diversion routes throughout Europe.
