Augsburg: How the Lech should be renatured – Bavaria

The Lech is 80 meters wide here, a few meters away from the Merching barrage just before Augsburg. “It used to be a kilometer wide,” says Eberhard Pfeuffer, a conservationist and author of several books about the river. Hucho swam in the water, the people of Augsburg caught 40,000 to 50,000 noses a year without harming the fish stocks. That no longer exists today, regrets Pfeuffer. “Unfortunately one has to say that the Lech is a river ruin.”

The expectations of the “licca liber” project are all the greater, which, among other things, is intended to give the river back some of its original character as a wild river over a length of around ten kilometers from here in the direction of Augsburg. The dimension of the renaturation project is “unique in Bavaria,” says project manager Sabine Winter from the Donauwörth Water Management Office. The river is allowed to swell to 130 meters, numerous bank structures are dismantled, a new, so-called secondary floodplain is created, a particularly valuable habitat for animals and plants. The process has been running since 2013, and like no other water body project in the Free State, citizens were included in the planning in a forum called the River Dialogue. The detailed planning should be in place by the end of the year, and the water rights process should begin in 2023.

Winter has now pointed out important cornerstones of the project directly on the banks of the river: Above all, the Lech should get more dynamic again, which like no other river in Bavaria is blocked by hydroelectric power plants and is therefore actually just a series of reservoirs. Fish can therefore no longer migrate, and the hucho, for example, is used artificially. Numerous fish species can no longer find gravel banks in the water to spawn. In the Augsburg city area, the so-called Flinz is already exposed, the layer of soil that is actually well covered with gravel in intact rivers. Eberhard Pfeuffer warns of a bottom penetration, the Lech would then disappear into the groundwater, which in turn would affect the drinking water supply around Augsburg. “We also have a great need for action in terms of hydraulic engineering law,” warns Pfeuffer.

The communities near the river should be better protected against flooding

After the renaturation measures, Winter confirms, the groundwater level will be stabilized and thus the future of the drinking water supply will be secured. Local residents have always feared the floods of the formerly raging river, which was also built in and thus tamed for this reason. Winter assures that the built-up areas, for example in the nearby municipality of Kissing, will even benefit from the rehabilitation of the river: Especially during flood events, the groundwater levels would sometimes even decrease. The demolished bank boundaries are to become soft, near-natural banks. Where necessary, safety devices hidden under gravel are intended to protect the adjacent settlements from the water of the Lech.

Open detailed view

The drinking water wells and nature reserves around the course of the river in the area to be rehabilitated made planning more difficult for the experts from the water management office. Some trees must not be cut down, which the river needs to become wider and wilder again. In some cases it was not allowed to intervene in drinking water supply areas. “We have found solutions,” says Winter. Four out of six so-called crash ramps in the river can even be dismantled, which prevent the river bed from deepening further. The remaining two structures are to be rebuilt so that fish can migrate through them. The plan is for the river to reclaim its territory as soon as the bank barriers are gone. As before, the Lech is to receive side arms that connect the river to the new floodplain and are important retreats for fish, for example, in the event of flooding.

“We will need patience,” says Winter. She doesn’t just mean the administrative processes. It is still unclear whether lawsuits will be filed against the renaturation and delay the project. Even when the project is complete, it will take the river 20 to 30 years to widen and reshape its banks. The newly created floodplain is then regularly flooded, the river meanders again, forming a gravel bank here and there and then changing everything again. The gravel will have to be added artificially, but after the construction work there will be more than enough of it: Winter and her team are planning a 95-hectare area around the shore – that’s about 133 soccer fields – sometimes up to two meters to remove. “I don’t currently know of any project that works on such an area,” says Winter.

Once, says conservationist Pfeuffer, the Lech was the most raging wild river in Bavaria because of its high gradient. The river is still ecologically important because it connects the natural areas of the Alps and Alb. Despite its construction, it is still species-rich. Experts discovered rare species such as cross gentian, bumblebee orchid, yellow ringed butterfly and whorl snails during investigations in the course of planning. “The natural Lech as it existed 100 years ago will not come back,” says Pfeuffer. The way it flowed through the landscape 100 years ago and destructively during floods is no longer compatible with modern civilization. “But we should give him some of his naturalness again.”