Sustainable drainage systems assessment and optimisation – a case study for Lussebäcken catchment, Helsingborg
Increase of urbanisation and climate change are two factors that have been highlighted as they influ- ence the hydrological cycle. Both result in increased in peak flow within urban watersheds, leading to downstream flood-ing and increased pollution. In order to address this, Sustainable Drainage Systems (SuDS) have been adopted to support peak flow reduction and increased baseflow. In the last decades, Helsingborg, in southern Sweden has witnessed several flooding events. With the aim to reduce flood vul- nerability, this paper presents an as-sessment of multipurpose constructed structures used in the drainage systems in the Lussebäcken catchment in Helsingborg and proposes ideas for optimisation of some of these structures. Using the computer software MIKE URBAN with MOUSE engine, rainfall-runoff was simulated and flow in the network system was com-puted. Three scenarios have been simulated: before 2008 when no additional ponds were added; the current situation including newly constructed ponds and wetlands; and a proposed modification to improve the regula-tion. The events on the 15/09/1994 and the 05/07/2007 was used for the simulations, as they were selected as two extreme rainfall episodes. The results show a 22% and 33% peak flow reduction in the mainstream around the most critical area.