Sustainable drainage is a major challenge for highway and environmental agencies to mitigate flooding and understand the optimum design parameters of pavement structure. This paper experiments the hydraulic properties of OASIS® phenolic foam material examining infiltration rate and steady-state behaviour, water storage capacity of different thicknesses of OASIS® material, and the effect of OASIS® material in deferring the water peak flow during rainfall intensities of 100 mm/h, 243 mm/h, 400 mm/h, and 563 mm/h. This paper designs an application programme that estimates the optimal thickness of OASIS® layer to retain 100% of stormwater for a duration of 15 min. The results from laboratory tests corroborate the performance efficiency of OASIS® material to delay peak stormwater flow and mitigate flooding. The OASIS® materials not only increase the ability of permeable pavement system to absorb and retain stormwater up to a saturation limit but also retain the nutrient contaminants infiltrate to groundwater. The designed application programme will help the designers and constructors to increases the drainage efficiency of pavement structure by estimating the optimal thickness of OASIS® layer required to delay peak stormwater flow during maximum rainfall intensities.