Technical-Economical Evaluation of integrated Surface Runoff Control Methods using StormCAD Model and LID-BMP Approaches

Urbanization and land use changes in urban environments have led to the development of impermeable lands in urban areas. the risk of floods in urban basins compared to non-urban basins has increased and has caused a lot of damage to urban infrastructure, it is necessary to use approaches that, preventing the detrimental effects on the urban environment, provide maximum efficiency in runoff management projects at the source. , in the present study, the combination of structural and non-structural methods of flood management and technical-economic comparison of these methods have been Studied. Bentley StormCAD software has been used as a hydraulic model for structural design and modern LID-BMP approaches have been used as non-structural methods for surface runoff management in Islamic Azad University of Najafabad. Modern approaches have included soakaway, infiltration trench, rain gardens, temporary dry detention basin and vegetated swale. The analysis of results and technical-economic evaluation is based on structural, non-structural scenarios and integrated approach. The results of hydraulic analysis have shown that the average flow rate in the network is 370 lit/s and the minimum flow rate is equal to 10 lit /s, which justifies the possibility of using non-structural methods. Comparison of methods has shown that the use of an integrated approach to a structural approach has reduced costs by 48% and runoff by 90% over a 2 to 10 year return period. During the 50- and 100-year return periods, it also reduced surface runoff at the outlet points of the basin by 74% and 59%, respectively.