Investigating the Performance of Bio-Retention Cell on Peak Discharge Under Different Design Criteria

Document Type : Research Paper


Water Engineering Department, Faculty of Agricultural Technology, University College of Agriculture & Natural Resources, University of Tehran, Tehran, Iran.



Low impact development (LID) methods are among the runoff control measures. The bio-retention cell is one of the low impact development methods that has been noticed due to the significant reduction in runoff volume and increase in infiltration. However, the overall performance of the bio-retention cell varies in different areas and different designs. In the present study, the performance of bio-retention cells was evaluated under different design conditions. Also, the SWMM model was used in the modeling of the study area (east of Tehran city) to evaluate the performance of the bio-retention cells. The results of the present study showed that the bio-retention cells are capable of reducing flood and increasing infiltration. Floods in the study area were completely eliminated after using the bio-retention cell for rainfall with a return period of two and five years, and for rainfall with a return period of 10 and 20 years, the flood volume was reduced by more than 90 percent. Bio-retention cells reduced the peak discharge by 65 to 25 percent for rainfall with a return period of two to 20 years. The results also showed that by increasing the thickness of the surface layer of the bio-retention cell, there would be even more runoff reduction. For rainfall with a return period of 20 years, increasing the thickness of the surface layer from zero to 450 mm caused a 41% decrease in runoff volume and a 1.5 times increase in infiltration. Increasing the saturated hydraulic conductivity of the soil layer of the bio-retention cell also increases the performance of this low impact development method. The present study shows that the use of infiltration based low impact development methods, such as bio-retention cell, can help in improving the hydrological conditions of urban areas.


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