´Side-channels at the Lower Rhine - more riverine nature along the waterway´

Final conference of the two EU LIFE projects ´River and floodplain revitalisation Emmericher Ward´ and ´Side-channel Bislich-Vahnum´

In the end of September 2019, river experts from all over Germany, the Netherlands and Austria met for a two-day lasting final conference of the two EU LIFE nature projects ´River and floodplain revitalisation Emmericher Ward´ and ´Side channel Bislich-Vahnum´. On the basis of the successful implementation of the two projects, there are now a flown through side-channel near Emmerich and a new side arm near Bislich-Vahnum connected to the river Rhine.

Approx. 80 participants from different institutions, e.g. certain authorities, the International Commission for the Protection of the Rhine (ICPR), nature conservation associations and other organisations followed the invitation for a lively exchange. Results and experiences from the ten-year lasting planning and implementation process of the projects were discussed in the conflicting demands of waterway, flood and nature protection – an exchange of experiences for the benefit of future work.

The project managers, Klaus Markgraf-Maué and Dr. Thomas Chrobock from the NABU-Naturschutzstation Niederrhein presented the two side-channel projects at the Lower Rhine stretch. Initial successes are e.g. the high densities of rheophile juvenile fish in the side-channel of the Emmericher Ward and the improvement of typical floodplain dynamics.

Additional presentations followed and indicated different experiences on side-channels along the Dutch sections of the Rhine, the river Elbe and the Danube. Luc Jans from Rijkswaterstaat referred to more than 30 years of experience with more than 30 different side-channels throughout the Netherlands and accompanied comprehensive monitoring programs. Their data provide valuable insights also for both side-channels on the Lower Rhine area. Christian Baumgartner presented measures in the national park Danube-Floodplains south east of Vienna, where much higher runoffs lead to more dynamic riverine and floodplain habitats devoid of problems with the waterway. Furthermore, the WWF river expert Georg Rast reported from his experiences from the Upper Rhine area and the river Elbe. Frank Collas from the Radboud University Nijmegen showed first results of the ecological accompanying investigation of parallel dams along the Dutch section of the Rhine which seem to provide highly positive ecological impacts. 

Within the scope of a moderated discussion, the challenges and perspectives of river and floodplain revitalisation measures on rivers used as waterways were debated with different representatives of the involved authorities of the Federation, the federal provinces, the waterway administration and the ICPR.

Project manager Klaus Markgraf-Maué (center),

Dietmar Abel from the Wasserstraßen- und Schifffahrtsamt Duisburg-Rhein,

Bernd Neukirchen from the Federal Agency for Nature Conservation (BfN),

Detlef Reinders from the district government Düsseldorf,

Dr. Anne Schulte-Wülwer-Leidig from the International Commission for

the Protection of the Rhine
 (shown in photo, from left to right).

The participants joined the subsequent workshops, thereby acquiring in-depth knowledge of diverse topics, such as side-channels and waterways, morphodynamics and maintenance as well as ecology of riverine habitats and their species. In the evening a common celebration for the successful realisation of the projects ´River and floodplain revitalisation Emmericher Ward´ and ´Side-channel Bislich-Vahnum´ took place.

During the final day of the conference an excursion led the participants to both project spots on the Lower Rhine and to an additional side-channel named Klompenwaard along the river Waal in the Netherlands.

Key aspects and results of the discussion from the point of view of the organisers:

> The ecological quality of sidechannels increases with the depth of the connection to the main flow and the frequency of run through.

> Examples from the Danube and Dutch river arms verify that side-channels can be connected to the main stream during low water discharge and even lower without interfering the waterway.

> Missing morphodynamics are relevant ecological detriments. Morphodynamics are a key factor for the success of side-channels. Therefore, it requires space and self-reinforcing morphodynamical processes in side-channels. 

>Side-channels are part of a dynamical river system. Adaptions and interventions for the preservation of the functions must be taken into account.

> There is a serious deficit of riverine and floodplain revitalisation in accordance with the European Water Framework Directive for the German section of the Rhine. Compared to that, in the Netherlands are more than 30 attached side-channels along the Rhine arms. In North Rhine-Westphalia there are only particular feasibility studies besides the NABU projects. The actions are on hold.

> The distribution of responsibilities between the federal and state governments and the associated legal framework on the federal waterways continue to significantly hinder the implementation of the necessary measures; the authorities are waiting for the reform of the waterways administration (WSV) and amendment of the BWStrG, which should enable the WSV to independently implement measures of ecological objectives.

> in this case, the WSV claims considerable personnel and time requirements before it can take on additional tasks.