The aim of river restoration is to return rivers and streams to their natural state and to improve their ecological status. Potential actors for river restoration measures are towns and municipalities, water management authorities, water maintenance associations, fishing associations and citizens' initiatives.
In many German rivers, the objectives of the European Water Framework Directive (WFD) were not achieved by 2015. For this reason, deadline extensions and exemptions were claimed for almost 92 percent of all German surface water bodies (BMU
2016). Nutrient pollution, hydromorphological pressures and inadequate implementation of river restoration measures are main causes of the deficient status of many water bodies in Germany (UBA 2017).
Consequently, hydromorphological improvements account for the largest share (41.5 %) of the measures planned by the German federal states in the WFD management cycle 2016-2021 (BMU/UBA 2016). The states largely rely on the cooperation and voluntary actions of local stakeholders when it comes to implementing restoration measures. The awareness and priority given to river restoration by local stakeholders should be strengthened because the future status of German rivers depends on how much attention is paid to rivers today.
River restoration is about the sustainable development of water bodies. Natural and near-natural watercourses have many advantages, e.g.:
They increase the quality of life as landscape-forming elements in urban and rural areas.
They reduce the risk of flooding for downstream users.
They provide habitats for numerous plant and animal species.
They support the degradation of environmentally harmful substances (e.g. wastewater, fertilisers).
They contribute to adaptation to global climate change.
Human uses cause damages, pressures and modifications of water bodies
Humans have always used and altered watercourses and floodplains for a wide variety of objectives, including land reclamation for settlements and food production, energy generation, drinking water supply, flood protection, discharge of treated wastewater, transport and recreation. In order to make these diverse uses possible, considerable interventions are necessary in the rivers and their surroundings. These interventions can lead to a reduced diversity of biotopes and species and even to the destruction of sensitive ecosystems.
Watercourses are often straightened, constricted or channelized and their floodplains are used or sealed right up to the riverbanks. These anthropogenic modifications affect the natural processes in the water body, flow velocity increases and the water retention of the floodplain is reduced. These processes cause rivers to incise and to loose connection to their floodplains: diverse habitats become monotonous channels. Excessive water withdrawal or input of pollutants through the discharge of wastewater or the inflow of fertilisers and pesticides from agriculture place an additional burden on watercourses.
Restoration measures improve the ecological status of rivers
The aim of river restoration is to develop rivers and streams towards a near-natural state. However, this does not mean that restoration can fully achieve a natural state. For every restoration measure, the natural reference conditions are compared with what is feasible and a realistic development goal is set.
Generally, river restoration should use a river's dynamics instead of reconstructing it, because every construction measure interferes with the aquatic ecosystem. In most cases, an initial measure is required to trigger river dynamics towards a near-natural state. Examples of initial measures are the removal of built-up embankments and bed fixation.
Measures for river restoration
Bulldozers are not always needed to restore a river. Lively waters manage their restoration themselves when space for development is provided and initiating measures trigger the dynamics of a river. If the watercourse cannot be changed, small measures can still considerably improve the structure of a river. Over 90% of German rivers and streams are straightened, constricted, piped or interrupted by structures such as weirs or barrages. Restoration can improve the ecological status and attractiveness of water bodies.
Planning, funding and participation are vital for successful river restoration
Sustainable river development is a complex undertaking. Clear restoration objectives must be defined, different interests must be balanced and various legal requirements must be taken into account. Well-structured planning and project management is necessary for a successful and efficient implementation of measures.
Depending on the type of restoration project, the costs can be very high. Therefore, the German federal states and the European Union offer numerous funding and financing programmes. In addition, river restoration projects can be used as compensatory measures in the context of impact regulation under nature protection law. Foundations and sponsors can also be considered. With a clever combination of several financing instruments, restoration projects can be financed up to 100 %.
Administrations, water management authorities, water maintenance associations, non-profit organisations, farmers and the local population (i.e. many stakeholders) are involved in river restoration projects. This can lead to conflicts, especially when it comes to the provision of land for water restoration projects. The executing agency should communicate with all involved parties at an early stage and in all planning phases. All stakeholders should be given the opportunity to participate. This promotes mutual understanding, creates acceptance and provides planning security for all.
The contents above are translated excerpts of an online platform on river restoration that has been created by the German Federal Environment Agency (UBA
). The platform seeks to motivate stakeholders to start river restoration projects. It has been designed for representatives of towns and municipalities, water management authorities, water maintenance associations, fishing associations, citizens' initiatives, etc.
Ten examples of river restoration projects across Germany where a wide variety of measures were implemented. This section includes many videos and photos that are worth watching even if you don’t understand German!
For our environment
The impact of climate change will be felt more strongly in the future – and in Germany too. This is the conclusion reached in what is called the vulnerability analysis, a comprehensive study on Germany's vulnerability to climate change.