Stormwater management practices can mitigate the undesirable impacts of urbanization. Urban drainage models can play a significant role in comprehensive evaluation of stormwater management systems. This thesis presents a methodology for the development of a detailed distributed urban drainage model using Geographic Information System (GIS) databases. The approach incorporates delineation of spatial variables (subcatchment outlets, width, slope etc.) and other model inputs from digital data and assigns them to the GIS database by executing developed Python 2.7 scripts. The proposed methodology is applied on a case study area in Mississauga, Ontario. Observed rainfall data are used as model input and simulation is performed using PCSWMM 5.1.1279. The model performance is evaluated by comparing the uncalibrated simulated discharge with the observed one. The simulated hydrographs are of good fit with the observed hydrographs. The evaluation criteria justify the use of extracted and assumed parameters and the reliability of the developed methodology.