Towards sustainable urban stormwater management

Abstract

New directives for the management of urban stormwater prioritize infiltration and direct discharge into receiving waters. This requires innovative new stormwater facilities in urban areas. Besides hydraulic requirements for retention and infiltration capacity, the pollutants contained in the runoff water are of primary importance in future stormwater drainage concepts. Different urban surfaces are classified according to their potential for pollutant wash-off and the most crucial substances in view of hazardous effects in the aquatic and terrestrial environment are identified. Source control of hazardous pollutants by choosing alternative materials for the construction of buildings, roads and vehicles is considered to be most sustainable but will only be effective on a longterm perspective. In addition, new facilities for decentralized hydraulic retention combined with barrier systems for the most hazardous substances are proposed allowing for ecologically safe discharge of the stormwater into the local environment. Soil passage and new adsorber systems in the form of different granular adsorbents have been investigated and turned out to represent efficient retention systems which can well be integrated into infiltration and hydraulic retention facilities. It is suggested that the structures for stormwater handling are integrated into local landscaping in the surrounding of buildings in the form of ponds, reed-beds, ditches, etc. creating attractive blue-green environments.