Author(s): J.B. Ellis; J. Marsalek
Keywords: Stormwater management; rainfall/runoff processes; modelling; CSO control; best management practices; regulatory programs
Abstract: Recent developments in urban storm drainage are reviewed starting with drainage impacts on receiving waters, followed by a brief analysis of selected components of urban drainage systems, hydroinformatics. and regulatory programs. Further advancement in drainage planning will require considerations of the catchment. drainage system, groundwater, treatment plant and receiving waters as one entity, and ensuring sustainable integrated development and ecological enhancement of urban streams and corridors. Such processes should be based on comprehensive modelling, which is well advanced for hydrological aspects, but further development is needed in water quality, sediment quality, transport and impacts, and ecological modelling. Mitigation of stormwater impacts is accomplished by best management practices, which form a part of the treatment train, and their sustainability has to be ensured by proper operation and maintenance. Impacts of combined sewer overflow are mitigated either conventionally by storage (and return to the central wastewater treatment plant). or more recently, by satellite treatment or pollution separation at the overflow points. An improved utilization of the available spare (idle) capacities in the drainage system can be achieved by real-time control. Finally. regulatory programs in various countries indicated a great deal of uncertainty and some aspects of such programs may even impede effective environmental practices.