Compact bioretention cell for urban stormwater management: Assessment of hydrologic, hydraulic, and water quality performance via laboratory and SWMM modelling

Bioretention cells (BRCs) are widely implemented to restore undeveloped hydrologic cycle; however, conventional BRCs need considerable surface area, limiting their applicability in densely populated areas. Compact BRCs like Filterra® have been designed to provide comparable hydrologic and pollutant removal effectiveness with a smaller footprint. The hydraulic characteristics of Filterra's engineered media were assessed through laboratory testing using KSAT and HYPROP devices and these results were integrated with field monitoring to implement a field-validated storm water management model (SWMM). Laboratory results showed a hydraulic conductivity of 1750 mm/h. The validated SWMM model replicated the outflow dynamics with satisfactory accuracy (KGE >0.35, R2 > 0.47), and the total suspended solids (TSS) removal was suitably predicted (R2 = 0.83). Results demonstrate that the field-validated SWMM model can be used to evaluate both hydrologic performance and pollutant TSS removal efficiency of compact BRCs, while noting its limitations in representing complex TSS dynamics.