Understanding of flooding behaviors required both spatial and numerical approaches. This can be achieved by integrating powerful spatial data management such as Geographic Information System (GIS) with hydrologic and hydraulic models. This article discusses the development of hydraulic model using XP-SWMM, a 1-D hydrodynamic model to simulate flood water of Damansara River at TTDI, Selangor. The simulation was focused on the time of water filling and volume of flood discharge (m/s) over the floodplain. The result showed 3 that time travel for flood water to reach crest level of 1.23m is only 1 hour 30 minutes. This when converted to flood volume are approximately 100 m/s covers an area of approximately 107 hectares of flooding area. The 3 hydrograph indicates that time travel to rise is only 30 minutes. The results demonstrate the advantage of the integrated tools of ArcView GIS and XP-SWMM as hydraulic software in producing a Flood Hazard Mapping for Urban Area (FHMUA) in the study area.