Krems River Flood Defences

The flood defences installed at the Krems River essentially included the expansion of the outflow cross-section, the optimisation of the bed slope in the framework of the conversion/removal of two weir systems, bank and bed protection by means of armourstones, the construction of side walls using armourstones and flood protection walls as well as the adaptation of supply, disposal and traffic infrastructure.

In the process, we secured the banks of the expanded cross-section using a natural-surface riprap made from armourstones which we set in concrete in areas with elevated bed shear stress. We executed the flood protection walls as angular retaining walls using the in-situ concrete method. To maintain the specified bed level and bed slope, we installed wales made from armourstones at a distance of some 50m to one another at bed level.

Furthermore, we removed and newly constructed the two existing weir systems. The so-called Pfannl Weir as a stone ridge weir and the Oser Weir as a boulder ramp. To uphold the stream continuum, we incorporated fish ladders into the weir/ramp structure.

Urban development measures and adequate planting significantly increased the Krems River’s leisure time and recreational value as an urban river system. The architectural design elements along the riverside path include benches, tables, contact areas and boulders made from precast concrete parts.