Hydraulic Engineering

Hydraulic Engineering

In the urban area of Donauwörth, between the old B2/B16 bridge and the new B2 bridge, a deepening of the central Danube riverbed of up to 2.5 m has been observed since 1985. In the thalweg (the deepest part of the channel), the gravel layer has been eroded in some areas, exposing the tertiary subsoil consisting of stiff to semi-solid clay. The most severely affected section lies between Danube km 2509.0 and km 2508.6, where three flood channels, which carry water during high-flow events, rejoin the Danube from the right. The resulting three-dimensional flow conditions cause erosion both on the riverbed and the embankments. There is an immediate risk of a „riverbed breakthrough“ during the next major flood, which would have grave consequences for the infrastructure situated along and within the Danube.

„CityRiver“ has taken on the task of preventing further riverbed deepening. This is to be achieved through innovative stabilization measures of the riverbed and adapted bed load management—specifically the targeted introduction of gravel. By preventing further erosion, the project protects the foundations of buildings on the Ried Old Town Island and ensures the maintenance of a navigable boat channel, among other benefits.