Lech renaturation: The revitalization of a river

According to project manager Simone Winter, the Lech renaturation just outside Augsburg will be unique in Bavaria: embankments will be dismantled and a floodplain with habitats for animals and plants will be created. You can find out all about the project in planning here.

The ambitious Lech renaturation project

A Lech renaturation project is taking place just outside Augsburg. Shortly before the Merching barrage near Augsburg, the Lech is 80 meters wide. It used to be one kilometer wide and was home to thousands of Huchen. Today, however, the Lech is more of a river ruin. The “licca liber” project aims to change this as part of a Lech renaturation project over a length of around ten kilometers. The river is to be restored to its original character as a wild river.

The plan is to make the Lech 130 meters wide. In addition, bank obstructions are to be reduced and new secondary floodplains created. The idea is to create a valuable habitat for animals and plants. The approval process has been underway since 2013. Numerous citizens have been involved in the planning process as part of the “river dialog”. The detailed planning for the project should be completed by the end of 2022. The water rights procedure will begin in 2023.

The stabilization of the river between barrage 23 and the mouth of the Danube is intended to repair damage caused by canalization. Translated, licca liber stands for “free Lech”. The renaturation is intended to bring the Lech back to its natural state. The Donauwörth Water Management Office is managing the project.

A series of reservoirs

The Lech is currently an obstructed river with numerous hydroelectric power plants. Described in the Süddeutsche Zeitung as a “series of reservoirs“, the river no longer offers any natural fish migration. Fish such as the Huchen have to be introduced artificially. In addition, numerous other fish species are faced with the problem of not finding gravel banks to spawn on.

In the city of Augsburg, the Flinz is already exposed. This is the bottom layer of rivers, which should be covered with gravel in a healthy river. Now there is a danger that the Lech could disappear into the groundwater. Among other things, this would affect the drinking water supply of Augsburg and the surrounding area.

Renaturation of the Lech is therefore also important for groundwater and drinking water. The current situation represents a vicious circle, as the many reservoirs for energy and drinking water production are damaging the groundwater. At the same time, the drinking water wells and the nature conservation areas along the course of the Lech are to some extent an obstacle to renaturation. Nevertheless, so-called drop ramps could help to make the Lech more natural again.

Fear of flooding

The Lech used to be a wild, raging river. Many local residents are rightly worried about flooding. This is one of the reasons why the Lech was tamed by partial canalization. However, according to project manager Simone Winter from the Donauwörth Water Management Office, restoring the river would reduce the risk of flooding. This is because the groundwater levels in a renaturalized river can be reduced in some cases. Safeguards are intended to help protect settlements near the river from flooding.

The Lech renaturation project will still take several years to be approved. In addition, it is expected to take another 20 to 30 years for the river to recover. The newly created floodplains will then be flooded regularly. The Lech will be able to meander, form gravel banks and change these again over time. A 95-hectare area is to be created around the banks of the river in order to remove up to two meters. The newly created floodplains will provide valuable habitats.

The sometimes feared river with its steep gradient is still ecologically significant today. It connects the natural areas of the Alps and the Alb. Despite the damming, many species can still be found here. Studies carried out as part of the licca liber project have uncovered rare species such as gentians, bumblebee dragonflies, yellow ringed fritillaries and diaper snails.

The challenges of restoring the Lech

Above all, the renaturation of the Lech requires a great deal of patience. The administrative processes can take years. There is also the risk of legal action against the renaturation, which could delay the project. However, close cooperation with the local population should guarantee broad support among residents.

The licca liber project serves as a role model, but only covers a few kilometers of the river. A total of 43 transverse structures line the Bavarian Lech between Füssen and the mouth of the Danube. This means that in many places the river resembles a sluggish canal whose ecological balance is in danger.

BUND’s Lech Future Program makes the following suggestions for renaturation of the Lech:

• Restore the dynamics of the river, for example by allowing natural water level fluctuations and relocating coarse material
• Reconnection of floodplains
• Restoration of bed load passability to allow sand, gravel and debris in the river
• Removal of lateral obstructions
• Restructuring of energy use on the Lech

The experts from BUND also point out that the climate and biodiversity crises are key challenges of our time. The renaturation of rivers helps to improve biodiversity and preserve the livelihoods of people, animals and plants. In addition, abandoning too many hydropower plants offers the opportunity to promote other renewable energies.

By the way: You might also be interested in the article on the book Fluss.Raum.Entwerfen. It presents various design elements for urban river landscapes.