In 2004, the Federal Institute of Hydrology (BfG) and the Federal Waterways Engineering and Research Institute (BAW) launched a joint research programme on the technical and ecological suitability of alternative concepts for the protection of river banks (Schmitt et al. 2018). Studies of hydraulic loads and the ecological potential of this type of construction, taking into account the impact of navigation, are being undertaken along selected stretches of waterways. At the same time, researchers are performing in-depth laboratory studies as well as model studies. Close cooperation between various departments of the BAW (earthworks and bank protection, navigation) and the BfG (landscape conservation, vegetation science, animal ecology) enables interdisciplinary project work from a technical and ecological point of view. Currently, this research has been extended to the waterways at German North Sea estuaries (Fig. 4).

Figure 4.

Biotechnical approaches to bank protection at German North Sea estuaries (Source: BAW).

Various biotechnical approaches to bank protection at inland waterways are currently being tested in cooperation with the Oberrhein Waterways and Shipping Office in a large-scale trial on a one kilometre long river section on the right bank of the Rhine near Worms (km 440.6 to km 441.6), i.e. on the largest and busiest waterway in Germany. In the study area, around 120 freight ships per day are operating. Depending on the discharge, the water level fluctuates by over 6 m. The embankments are also relatively steeply inclined. In four test fields, the stone embankments above the mean water level were replaced by willow spreaders, pre-cultivated reed gabions and plant mats or stone mattresses. In another four fields, the stone fill was preserved and ecologically upgraded by various measures. The bank was planted with grazing poles and machines, with bushes and hedges, the bank structure was improved with gravel, large individual stones and deadwood; in addition, protected areas were created by a bank stabilisation of stones in front of the embankment. For comparison, one test field remained without protection (Schilling et al. 2013).

The results of research and best practise examples are presented on the internet: https://ufersicherung.baw.de. The aim of this project is to develop recommendations and basic principles to facilitate an application of the newly-developed methods for bank protection of inland waterways (Söhngen et al. 2018).

Another example of successful and integrated planning, with the early involvement and inclusion of stakeholders, is the flood spillway project near the city of Rees on the lower Rhine (Fig. 5, WSV 2012; BUND 2013). Since the purpose of this federal project is to provide flood protection in addition to preventing erosion of the river bed, it is also co-financed by the state of North Rhine-Westphalia. The Rees flood spillway helps to counteract the lowering of the groundwater level and improves the habitats for wetland fauna and flora. New shallow water and mud areas enliven the wetland fauna. As a result, the species diversity of grassland birds in the floodplain landscape can increase again. The project has gained recognition at European level and has been included in the EC Guidance Document on Inland Waterway Transport and Natura 2000 (EC 2018). In 2014 the bypass on the Rhine was awarded the “Working with nature Award” at the 33^rd PIANC (World Association for Waterborne Transport Infrastructure) World Congress (PIANC 2014).

Figure 5.

Rees flood spillway (Source: BAW).

In Germany, the WFD was primarily transposed into national law by the Federal Water Act (WHG) and taken up in the laws of the Federal States. With the 2010 amendment to the Federal Water Act, the WSV has taken over responsibility for maintaining and restoring ecological patency at the dams it constructs or operates on federal waterways.

220 weirs in the federal waterways require measures, i.e. structures must be newly constructed or repaired to enable accessibility for fish and macrozoobenthos in order to reach the goals of the WFD. This requires resources to the order of (a currently-estimated) 1 billion euros. In addition, regionally varying management responsibilities need to be coordinated and a variety of economic, ecological and political requirements need to be taken into account. For example, the sometimes complex and technically demanding integration of new fishways into existing structures makes it difficult to implement measures in a timely manner and may lead to conflicts with other objectives (of utilisation) such as energy production by hydropower plants. In addition to the coordination of different interests, the planning processes themselves can be lengthy. At the same time, however, the WFD’s timeframe for achieving the objectives is tight. For this reason, synergies with already-planned measures (such as the restoration or replacement of defective weirs) are increasingly sought in the implementation of the measures.

Another challenge is the great need, especially for fishways on large water bodies, to close gaps in our knowledge of fish behaviour in relation to topography, geometry and hydraulics in the access area and within ladders in order to be able to guarantee sufficient functionality of the new facilities. A pilot project for monitoring and research is the Mosel fishway near Koblenz (Fig. 6). The successful cooperation between the WSV and the state of Rhineland-Palatinate was crowned by the opening of the modern fishway in September 2011. In March 2012, the first upstream-migrating salmon was registered and in July 2013 a shad was seen for the first time in 60 years to ascend the river Mosel. All in all, the fishway has proven to be passable for most fish species and sizes, leading to notably high yearly numbers of ascending fish (e.g. more than 230.000 in 2015 (BfG 2017)). The state of Rhineland-Palatinate has moreover built a visitor centre, the “Mosellum”, where visitors can immerse themselves in the world of migratory fish.

Figure 6.

Mosel fishway near Koblenz (Source: BfG).

To approach all the aforementioned challenges, an implementation strategy, which takes into account different ecological and economic requirements, reflecting political and administrative boundaries and providing a strategy for closing knowledge gaps through research projects, was developed at the federal level (BMVBS 2012; BMVI 2015; BfG & BAW 2017). The prioritisation for the implementation of measures (BMVI 2015) is currently updated and will be integrated into Germany’s management plans for the third implementation cycle of the WFD.

These examples are only a small selection from the wide range of measures with which the WSV in Germany contributes to the preservation and promotion of biodiversity on watercourses as linear landscape structures within the framework of maintaining the waterways, but also in the course of compensation measures for expansion projects and in the fulfilment of legal obligations.

However, the fulfilment of legal tasks is only one side of the coin for achieving water-ecological objectives. If someone wins one hundred percent (e.g. nature conservation) there are usually also losers (often e.g. agricultural land). In our participatory and federal society, there is no progress in the implementation of measures on waterways without taking into account the users and social groups as well as institutions concerned. For this reason, the BMVI together with the WSV are increasingly focusing on dialogue and communication and integrated project planning, e.g. LIFE projects, funded by the EU.

A new floodplain has been created from 2011–2013 along the river Neckar near Stuttgart: the “Zugwiesen”. The “Zugwiesen” project became the responsibility of several stakeholders, who normally have different fields of activity and whose interests are occasionally in conflict. The WSV, on the one hand, is responsible for the river Neckar and its utilisation as a traffic route; the city of Ludwigsburg, on the other hand, has responsibility for the larger river bank areas. Both sides put forward convincing arguments and showed creativity which resulted in a joint concept. As the concrete slabs on the left Neckar embankment exhibited considerable damage, the Waterways and Shipping Office Stuttgart decided to integrate reconstruction works into the ecological redevelopment of the “Zugwiesen” floodplain. The embankment was levelled over a length of 800 metres. The former wall was removed, the river and the floodplain were reunited (Fig. 7).

Figure 7.

LIFE+ project “My favourite river” Zugwiesen (Source: Jochen Faber, INFO & IDEE GmbH).

The Zugwiesen-project clearly shows that the banks of a river can offer exemplary habitat conditions, even if there is high traffic from ships. Diverse habitats for plants and animals invite visitors to observe and learn while getting some fresh air. Federal and local government have engaged in an unprecedented level of cooperation to realise the project. The new “Zugwiesen” floodplain covers an area of 17 hectares and includes a new water body with an area of 40,000 sqm. The former bank reinforcement was broken up and vegetation planted for a near-natural bank protection, resulting in the restoration of the entire large area along the Neckar bend. Meadows, an alluvial forest with willow and alder trees, still-water bodies with islands, wetlands and ponds as well as a brook winding its way through the area provide a habitat for animals and plants. An observation platform, the “Stork’s Nest” enables visitors to observe even those protected parts of the area that are not allowed to enter (https://neckar.ludwigsburg.de/start/Projekte/Zugwiesen.html).

Some minor waterways in Germany are no longer used for the transport of goods as they had been before. For some of these waterways, development strategies to reduce infrastructures that are no longer required and the enhancement of opportunities for ecological development and recreational activities are discussed. The integrated European Union’s LIFE-project “Living Lahn - one river, many interests” (2015–2025), conducted by the federal state of Hesse together with the federal state of Rhineland-Palatinate, the WSV and the BfG aims at helping to restore the “good ecological potential” of the federal waterway Lahn. At the same time, the interests of shipping and other competing uses will be integrated in accordance with ecological requirements. This project creates best-practice examples for other rivers. “Living Lahn” was the first integrated LIFE-project, which has been funded in Germany by the European Commission (HMUKLV 2021) (https://www.lila-livinglahn.de/en/start).

The project partners are:

• Hessian Ministry for the Environment, Climate Protection, Agriculture and Consumer Protection;
• Ministry for Climate Protection, Environment, Energy and Mobility of Rhineland-Palatinate;
• Directorate for Infrastructure and Approval North;
• Governmental Authority of Gießen;
• Waterways and Shipping Office Mosel-Saar-Lahn;
• German Federal Institute of Hydrology.

The first main objective of the Living Lahn project is to enhance the ecological status and connectivity of the river itself while simultaneously enriching the quality of life along the river. This aim will be reached through practical projects such as

• Restoration of natural retention areas and their self-regulation.
• Identification of pollution sources and their elimination in order to improve the water quality.
• Improving structural diversity in weir-regulated river stretches.
• Implementation of measures for restoring the linear patency in different types of locks and weirs, thus leading to a direct improvement of the water-bound habitats and their different animal and plant species.
• Promotion of sustainable tourism offers e.g. in the field of canoeing/rowing by constructing new portage sites as well as by providing a “Lahn App” for better planning of leisure activities.

The second main objective is to develop an overall concept, the so-called “Lahn-Concept”, which takes into account its further ongoing use as a federal waterway as well as water ecology and revitalisation aspects and flood protection. Ever since 1981, the Lahn has no longer been used for freight transport. The weir buildings partly need substantial restoration and maintenance works, calling for urgent action from the responsible authorities.

The Lahn-Concept pursues a holistic approach, in order to integrate the numerous interests, usages, and stakeholders, and, of course, the Lahn River itself, into the development process. With the participation of all project partners and the interested public, the Lahn-Concept offers a unique opportunity to ‘re-invent’ the technical maintenance of the Lahn, to enhance the ecological health and connectivity of the river itself, to improve the potential for tourists, to implement the goals of the Water Framework Directive and to consider further relevant correlations. The challenge will be to balance competing interests as there are flood protection, nature conservation, shipping, water conservation, economic efficiency, hydropower, tourism, agriculture, fisheries, and more.

For this purpose, the responsible project partner Waterways and Shipping Office Mosel-Saar-Lahn involved the public in a dialogue process at an early stage. Transparency and acceptance among the population will be fostered by regular publications, working groups and workshops, wherever necessary in order to collect feedback from relevant stakeholders.

The question of retaining or tearing down weirs to reach different objectives is often at the heart of the discussion process. As a way to rationalize discussions (and, possibly, decisions) concerning this topic, a study was set up to examine the effects of the removal of selected weirs on ecosystem services (ES). In this study, which is in its final stage, the RESI (River Ecosystem Services Index, Podschun et al. 2018) approach is utilised. The case study has already been used to refine parts of the ES concept (Albert et al. 2020). Moreover, the BMVI is currently discussing the use of certain ecosystem services indicators for future decision processes concerning traffic projects.

The WSV is responsible for approx. 2,800 km of secondary waterways. They have lost their importance for freight traffic due to changing transport flows and ship sizes and are now mainly used for tourism. Thus, it will be a key issue to elaborate concepts and perspectives in order to face challenges arising from the development described above. The common elaboration of the Lahn-Concept is considered a pilot activity for the WSV and can serve as a blueprint for further sustainable development concepts of other federal waterways of the same category.

In the past, various demands for use of the Elbe River, such as shipping, nature conservation, flood protection, tourism and port management, have led to controversial disputes between the actors involved. The Binnenelbe upstream from the weir Geesthacht is home to valuable natural and cultural landscapes as well as original habitats of outstanding importance. The Elbe River landscape is a model landscape for sustainable development of the United Nations on more than 400 kilometres of the river as the oldest German UNESCO-biosphere reserve (https://www.flusslandschaft-elbe.de/start/?changelang=2).

Against the background of the different utilisation claims with legal obligations and the transferred responsibilities, the German Federal Ministry of Transport and Digital Infrastructure (BMVI) together with the Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), agreed at the federal level at the end of 2010 on a paper of key issues for an overall concept for the Elbe. In subsequent years, the overall concept Elbe (Fig. 8) was consolidated and institutionalised in a broad dialogue with federal states and various stakeholders in numerous conferences and consultations. Today, it has rules of procedure and bodies for cooperation at steering and working level. It forms the foundation for the long-term development of the Elbe upstream of Geesthacht, both as a shipping route and as a valuable natural area, taking into account other interests of use (https://www.gesamtkonzept-elbe.bund.de/Webs/GkElbe/DE/Home/home_node.html).

Figure 8.

Overall concept Elbe (Gesamtkonzept Elbe) (Source WSV).

The overarching objectives are to combat erosion, improve flood protection, reduce inputs of contaminants, improve shipping conditions and maintain and restore habitats and habitat types in waters, banks and floodplains.

The implementation of the overall concept is not the sole responsibility of the German federal government. The federal states also have some essential responsibilities - such as flood protection as part of water management, nature conservation, tourism and port management. In its course and with its tributaries, the Elbe River touches ten of Germany’s 16 federal states. This is a task for the next decades.

“Germany’s Blue Belt” is one of the BMVI’s new flagships. It is a Federal Government programme in cooperation with the BMU. After the initial impulse from the coalition agreement of the Federal Government in 2013, and some years of political activities and conceptual preparatory work, the operational phase of the „Blue Belt“ programme started in 2019 (https://www.blaues-band.bund.de/Projektseiten/Blaues_Band/DE/neu_01_Bundesprogramm/bundesprogramm_node.html). It aims at developing a system of interlinked biotopes of national significance along Germany’s federal waterways within the next decades and provides an opportunity to link adapted infrastructure standards to ecological objectives. This will also help to make these regions more attractive for leisure and recreational activities.

One important part of the implementation is the Federal Floodplain Programme which is managed by the Federal Agency for Nature Conservation (BfN). Measures strengthening lateral connectivity between rivers and floodplains are of special significance within the programme. In parallel, the objectives of the WFD and the Natura 2000 Directives are supported.

“Germany’s Blue Belt” establishes a framework for action over the coming decades. Although it focuses on the network of minor waterways, it also defines “ecological stepping stones” for the very busy federal waterways. Such renaturalisation measures may include the reconnection of abandoned meanders and flood channels or the levelling of banks, provided that this is also compatible with the transport of freight. However, if rivers, banks and floodplains are developed as a holistic entity, also areas will be affected that are not owned by the Federal Government. Here, a financial-assistance programme of BfN creates incentives for supporting the restoration of habitats typically found on floodplains. The budget of the Federal Ministry for the Environment for 2020 e.g. provides 6.8 million euros for the Floodplain Programme. For the years 2021 to 2023 there are commitment appropriations of around 25 million euros (https://www.bfn.de/blauesband/foerderprogramm-auen.html).

Most of the watercourses in question, namely the federal waterways, are owned by the German Federal Government. It is thus a good idea to task the WSV with implementation of this programme, especially as it already has the necessary expertise and experience.

In 2016, the Federal Waterways Administration launched five model-projects (BMVI & BMU 2020) (https://www.blaues-band.bund.de/Projektseiten/Blaues_Band/DE/neu_04_Projekte/Aktuelle_Projekte/Projekte_node.html).

One model-project, the bank renaturation “Kühkopf-Knoblochsaue” on the river Rhine (Fig. 9), was hailed as a successful example as part of the UN Decade of Biological Diversity in 2020.

Figure 9.

Germany’s Blue Belt model project “Kühkopf-Knoblochsaue”, River Rhine km 474.0–476.5.

While launching the Blue Belt programme, it quickly became clear that the existing legal obligations of the WSV were not sufficient to carry out major renaturation measures that are to be classified as water management expansion. To enable the WSV to manage all these tasks in an appropriate manner, the BMVI and the BMU pursued an extension of legal tasks to allow the WSV to support the goals of the WFD to an extended degree. A corresponding amendment to the law was prepared by the German Federal Government in coordination with the Water Management Administration of the Federal States. On 09 June 2021, the new law came into force. The Federal Waterways Administration is now given the sovereign task of implementing water management expansion measures to achieve the hydromorphological objectives of the WFD. This kills two birds with one stone: the implementation of Germany’s Blue Belt will be fully enabled administratively and the WSV can contribute actively to the achievement of the WFD objectives. This new legal task for the WSV will significantly advance and help to accelerate the implementation of the WFD on German federal waterways in the upcoming years and decades.