Renaturation projects that include the reconnection of side-arms and riverbank restoration, the construction of new gravel islands and bedload management, restocking of sturgeon populations and habitat modelling, protected riparian woodlands with old trees being utilised as home for bats, nurturing meadows on dams to attract orchids, butterflies and bees, the renovation of dams to enhance the protection and well-being of terrapins, ecologically coordinated schedules for construction projects, nesting aids for swifts, newly created amphibian pools, species mapping, and knowledge management for environmental issues - the list of viadonau’s environmental services is both extensive and diverse.
S ince 2017, viadonau’s environmental services have been bundled together to form an integrated Natural Resources Management System, with each individual measure being tested in advance for its effectiveness. Following implementation, achievements are evaluated and the financial resources for each individual project documented. An annual steering committee then guides the orientation of the nature-relevant business activities for the following years. The goal is to focus resources on those projects that bring the greatest benefit to natural habitats along the Danube. Criteria for objectives are then formulated to assess environmental benefits. The Natural Resources Management system comes with just a few easily measurable key parameters, which are collated and documented annually. Behind every "dry" indicator is a wide range of diverse ecological goals. The conclusion is, nevertheless, very simple: the larger the key figures, the greater the environmental benefits of each project.
Examples of renaturation projects range from the reconnection of side-arms, the modification of groynes and the creation of gravel islands as part of bedload management, to large-scale riverbank renaturation projects. Three key indicators are recorded annually: the length of connected side-arms, the length of the newly created natural riverbanks and the amount of repositioned bedload gravel. The achievement of ecological objectives is even more exciting: when these three key figures increase, the habitat potential for fish living in fast flowing water also increases. Gravel islands become potential breeding grounds for birds such as little ringed plovers, common sandpipers and the common tern. Spawning grounds are also created for gravel spawning fish. Bird that build their nests in steep banks such as kingfishers, bank-swallows and bee-eaters find new homes and active bedload management alleviates the deterioration of the Danube’s riverbed, thus preserving the vital exchange of water between the river and its shorelines.
The same simple evaluation system is also used to assess on-land activities that enhance the natural environment, such as meadow maintenance and the preservation of riparian woodlands. This includes not only the mowing of grass on dams, but also their renovation and other construction measures that are carried out in as natural a way as possible. Management of meadows and grasslands also covers neophyte control and species conservation projects, including protection measures for the Zerynthia polyxena butterfly and orchids. The annual recording of results is again extremely simple and creates a balancing act between the various different types of measures: Meadows and areas of natural forest are cultivated according to strict ecological criteria and in the case of construction projects, the natural balance is assessed before during and after the project. Once again, an ecological system of objectives is at the forefront, whereby viadonau ensures that maintenance and construction measures are carried out in as naturally a way as possible. These measures benefit dry grasslands and species-rich meadow communities with their typical inhabitants of bees, butterflies, grasshoppers and lizards, with the dams also serving as feeding areas and migration corridors.
The first signs of success are already visible. Between 2017 and 2018 the key indicators for ecologically valuable meadows and natural woodland areas that fall under viadonau’s area of responsibility showed a clear improvement. This positive trend can also be seen with the company’s renaturation projects. The Natural Resource Management System is clearly a tool which will guarantee the preservation and development of the Danube’s natural habitats in the future.