Flooded areas reduction analysis by means of low impact development, rain barrel

Urban floods management and its problems reduction, applying modern methods such as low impact development (LID), can be considered as one of the main measures in this context. In this study, urban storm water existing network is analyzed to find flooded areas in some parts of Tehran district number 13 using EPA-SWMM mathematical model. After creating storm water existing network model, storm event with return periods (RPs) 2, 5 and 10 years have been selected. Results show that in comparison with total runoff, flood volume of flooded areas in each RPs is 19.3, 24 and 27 percent, respectively. Thus, storm water existing network can only pass some parts of runoff and the rest causes urban inundation. After that, applying Rain Barrel (RB) as a low impact development technique, with two different sizes for all RPs mentioned above, were studied. Based on the results, flood volume exit out of the flooded areas for RB smaller size was reduced 47, 21.6 & 9.7 percent and for RB larger size 47.3, 39.6 & 38.7 percent for all RPs mentioned above respectively. Comparison between LID technique and Non-LID technique shows that novel approaches such as rain barrel as a LID technique can reduce negative effects of small storm events 40 percent approximately.