A river is released from its bonds
Massive human intervention had turned the Lippe into a waterway that was low-maintenance from a water management perspective, but far-removed from nature. The water typically flowed between uniform embankments reinforced with rocks. The advantage of this was that even during heavy rainfall events, rapid drainage of the water was ensured; however it was not possible for a diverse watermeadow landscape to arise on the banks.
Space for meanders
For the Lippe to become a near-natural river again, these shackles had to be broken. Over around 30 kilometres of the river, this has already taken place. Once the rock ballast is removed, the natural shapes of a meandering lowland river quickly reform. Typical features include the interplay between steep undercut banks on the outside of river curves, and flat point bars on the inside. Underwater, this profile continues in zones of deep and shallow water, which offer a wide range of habitats. By building simple embankments and islands, the river can be assisted in the development of the most varied landscape possible. Further shackles take the form of riverbank levees, rises along the river that prevent the creation of regularly flooding watermeadow areas. If these levees are broken through in a number of places, the terrain behind can again be flooded regularly. The creation and restoration of flood channels performs a similar function, providing a natural connection between river and watermeadows.
In the watermeadows, standing water and flood-pools form the habitat for animal species such as amphibians, dragonflies, beetles, fish and birds. Flood-pools are shallow hollows in the terrain that are filled with water for at least some of the time, and which represent important habitats and refuges for animals and plants. Standing water is filled with water all year, and can be up to two metres deep. It does not freeze over in winter, and thus ensures plants and animals survive until spring. The grasslands of the watermeadow were previously wet, and were often underwater in winter. To improve the management of these areas, drainage systems and ditches were built, and the watermeadow was thus drained. In order to restore the natural state, these ditches are now being closed again.
Rare dune vegetation
For a sandy river like the Lippe, sand dunes were previously typical of the riverbank area. However, the intensive management of the watermeadows caused these to progressively disappear. The material excavated during restructuring work can now be used to create dunes again. These are very low in nutrients, and therefore an important location for plant communities that have today become rare, e.g. sand grassland. Furthermore, they offer habitats for ichneumon wasps, tiger beetles, little ringed plovers, and other animal and plant species.