Investigation the Effect of Low-Impact Development Methods of Rainwater Storage Barrels and Infiltration Trenches on Reducing the Peak Discharges of Urban Floods

Around the world, including in Iran, urban development has led to an increase in impenetrable areas and severe flood events. The purpose of this study was to simulate the surface runoff collection network in District 2 of Tehran Municipality (Ivanak) using the computer model SWMM. Considering the current state of the urban water network, low-impact development methods have been used to reduce peak flood discharge. In this research, rain barrels, infiltration trenches, and a combination of them were used as low-impact development methods. By implementing several low-impact development (LID) techniques, peak flood discharge in the return period of 10 years for the rain barrel method (first scenario), rain barrel method (second scenario), infiltration trench method, and combined method was reduced by 22, 31, 29, and 50 percent, respectively. Accordingly, each method's cost was estimated by its volume of water storage. Considering the 10-year return period, for storage of one million liters, the costs are 20.20 billion Rials in the rain barrel method, 11.68 billion Rials in the infiltration trench method, and 14.696 billion Rials in the combined method (infiltration trench and rain barrel). According to the results, the infiltration trench method was identified as the most economical method studied in the region.