 Abstract: Prior to any construction work related to stormwater, it is preferable to involve a computer-based modelling. This paper outlines two different computer-based modelling tools to model a green technology named StormPav Green Pavement. In determining befitting software for use, two key factors are considered: (i) fast model construction (ii) provision of an affordable design model. To meet these key factors, the Storm Water Management Model (SWMM), and InfoWorks Collection System (CS) are deployed in this study. The predictive results of the two models are compared for different design storm durations under 10-year Average Recurrent Interval (ARI). The predictive results suggest that both models are compatible. Yet, SWMM is preferable to model StormPav Green Pavement as it could provide reasonably fast model construction and the software tool is an open source software used worldwide.Index Terms : Computer-aided design, flow rate, permeable road, urban drainage, velocity.

Abstract: This study focuses on the possibility of On-Site Stormwater Detention (OSD) underneath a residential car porch. The space provided in the car porch area can be made good of it by introducing an OSD beneath it to temporary store stormwater from roof during raining in hoping of reducing the surface runoff. The OSD is subjected to 15-minute, 10- year Average Recurrence Interval (ARI) design rainfall. This process in urban hydrology is presented by using Storm Water Management Model (SWMM). Efficiency of the OSD is also investigated by different number of orifice outlets. Modelling efforts report that one orifice outlet is preferable, and it marks approximate 95% discharge reduction at the outfall.

StormPav Green Pavement System is a non-commercialized permeable road with a function of stormwater detention. This paper demonstrates the application of the R&D product in part of a 14,000 m2 government building complex as a new feature of sustainable drainage system. To assess its stormwater impacts to the project site, two software are utilized to analyze the stormwater flow processes when merely 10% of the project area is incorporated with StormPav. Firstly, Storm Water Management Model (SWMM) is used to simulate the project-wide stormwater flow, in which reductions between 22% - 6% in terms of peak flow rates are predicted compared to conventional drains when subjected to 5 – 180 minutes of 10-year Average Recurrent Interval (ARI) design rainfall. Secondly, SolidWorks Flow Simulation (SWFS) simulates the detailed flow processes within the StormPav system, in which it is found 0.5 – 1.3 m/s of velocities are predicted around the inlets and outlet that conform to the local stormwater management standard. Besides, SWFS allows visualization of velocity and streamline profiles across the StormPav system that conventional SWMM could not provide.