Danube II - Integrated River Engineering Project on the Danube to the East of Vienna

Besides the Wachau section, the stretch between Vienna (Freudenau) and the Slovakian border is the last free-flowing reach of the Austrian Danube River. This section is characterised by an ongoing riverbed degradation of about 2 cm per year (although bedload is added continuously by Verbund HP). Therefore and because of the heavy regulation measures at the end of the 19th century a negative influence on the ecological status and rather poor habitat structure is given within the national park “Donauauen”. Furthermore critical spots for inland navigation exist, leading to insufficient fairway depth at low flow conditions and high maintenance costs. Thus an urgent need for action is given. The “Integrated River Engineering Project on the Danube to the East of Vienna” aims to stop the ongoing riverbed degradation by implementing river engineering measures within the reach between the hydropower plant Freudenau and the Slovakian border (river-km 1921,0 to river-km 1872,70). Due to new river engineering measure types for river bed stabilisation (granulometric bed improvement) and the interaction with different innovative measures (e.g. new groin shapes), a broad integrative interdisciplinary monitoring including hydrology, hydraulics, sediment transport, geomorphology and various special fields of ecology is conducted. Within this monitoring task, interdisciplinary prognostic models are developed to provide essential information for project evaluation and optimisation of the measures.