The urban development structures were decided through a competitive process. The area is characterised by high building density, with limited site availability. In order to optimise the technical infrastructure igr prepared a surface water management study. The goal was to manage accumulating surface water on site, preferably to let it seep away, and to relieve pressure on the municipal waste water network. The foundation soil reports showed the subsoil to have unfavourable infiltration characteristics, which precludes a surface infiltration system. Additional investigations are currently underway to check seepage capacity in deeper soil layers (more than 3.0 m below ground level). The design provides for rainwater to be led near the surface within the road structures and green areas. The material make-up of the various development areas was considered and examined for various options. In addition, infiltration ditches and sewers will be used for water retention and discharge. Drainage corridors will be established through careful handling of road levels; these will ensure that during heavy rain events (urban flash floods), flood waters are processed in the least damaging way.  



Bernd Piechottka