The influence of depression storage on runoff from impervious surface of urban catchment

This paper contains results of a depression storage investigation based on simulations of runoff using SWMM 5 software and measurements from a real urban catchment in Poznan, Poland. The catchment area is 6.7km(2) and its average imperviousness has been evaluated as 29 %. Altogether, 46 rainfall events, registered by tipping-bucket raingauges in years 2006-2010 in three stations, have been analysed. The best agreement of the computed outflow hydrographs with the results of measurements has been obtained for a depression storage depth of 1.5mm. The influence of spatial distribution of impervious surface depression on the shape of the computed hydrographs has been found to not be significant.