Planning and optimization of green infrastructures for stormwater management: The case of Tehran West Bus Terminal

Green Infrastructures as Best Management Practice (GI‐BMP) play important role in preserving cities from urban flood and excessive runoff. In the process of using GI‐BMP in cities for stormwater management, a number of steps are taken that normally include selection of suitable sites, formulating proper combination of infrastructures, and optimization of the place and design of GI‐BMPs to maximize their cost‐effectiveness. This paper presents a site‐scale GI‐BMP implementation in Tehran West Bus Terminal (TWBT), Iran. To achieve this goal, this study applies a three steps framework namely GI‐BMP suitability analysis, GI‐BMP combination planning, and GI‐BMP optimization. In the first step, using the BMP Siting Tool, the suitable places for allocating GI practices were identified. In the next step, suitable GI‐BMP practices, including permeable pavements, bioretention basin, infiltration trench, and rain barrel were planned and arranged for each subwatersheds of the study area. In the third step, with the use of System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) model and NSGA‐II algorithm, the sizes of the planned GI‐BMP types were optimized for each subwatershed. The results indicate that runoff problem caused by surface runoff in the study area was serious and needed to be controlled. The results also revealed that there were 104 near‐optimal solutions that help reduce runoff volume by up to 70%. According to the results, applying GI‐BMPs in TWBT will reduce 60% of flow volume in the site with the price of 353,568$. This research is of practical importance for stormwater management using nature‐based solutions in bus terminals.