Author(s): Zeying Li; Kit-Ming Lam
Linked Author(s): Kit Ming Lam
Keywords: Rain garden; Bioretention; Biofiltration
Abstract: Bioretention is one of the stormwater control methods which has been adopted in the US, Germany, and Australia. The benefits of bioretention are known qualitatively, but there are still no adequate quantitative data on the actual contribution to improvement of urban hydrology remediation as well as stormwater treatment in different regions and under different operating conditions. This research focuses on verifying the hydrological performance of an experimental bioretention cell with a mild slope gradient on its soil surface. The design of the experimental bioretention cell is described in this paper. In addition, a pilot-scale 0. 8 m × 0. 6 m physical model of a bioretention cell with 0. 17 m soil depth has been constructed to select the appropriate soil media according to three target parameters: peak flow reduction, volume absorption, and delay of time of concentration. Flow measurements were made on this physical model for a number of inflow conditions and the results showed that peak flow could be reduced by 20-50% if no overflow occurred; and the time of concentration could be delayed by 9 to 30 minutes. There were little variations in the volume of stormwater absorption in the cell.