Connecting the Waters
Reconnecting side channels of the Danube requires the development of dynamic bodies of water. Habitats dependent on such dynamic conditions (bluffs, pioneer areas, sediment banks etc.) and specialised species (kingfisher, other water fowl such as the Common Sandpiper which nest on gravel surfaces, river fish species, pioneer plants, and species thriving in currents) will again receive much-needed support. Similar successful projects in water connectivity have already been carried out in several locations in the Donau-Auen National Park.
Regelsbrunn - Maria Ellend watercourse network
The first measures were taken at this site as a pilot project. By lowering the bank by 1.5 m to a length of 32 m, building a culvert and opening traverses, water was able to enter the Regelsbrunn floodplain again. The experiences led to more far-reaching measures in the follow-up projects.
Water Connectivity in Orth
Upstream from Orthan der Donau, three Danube inflow areas into the Little Binn and Big Binn were re-established by removing the solid embankments along the river
A traverse structure was removed completely from the side channels and another was equipped with a massive bridge passage. In addition, old rip-raps were removed from the stream and an extensive amount of documentation was obtained from the site.
Since then, significant changes in the water flow of both have been observed. Deposits which have accumulated in the past 100 years have been washed away, at least in part. On a smaller scale, the effect of these changes may also be seen in the composition of the communities of species.
Connecting the Waters in Schönau
In Schönau, two lowerings of revetments along the river were carried out. As well, the traverses dividing the stream of water were partially opened and equipped with a novel, 20-meter wide bridge passage.
In the upper reaches of the project area, the measures undertaken have effectively prevented or significantly slowed the long-term accumulation of build-up. And the maintenance of a dynamic, fluctuating environment in the middle reaches is now assured.
In the lower reaches, increased and more frequent inflow has improved water quality and reduced the entry of contaminants via the reverse flow.