Abstarct: The urban growth and city sprawl resulting increase of impervious areas leads to the runoff in the city. Determining flood-prone areas as well as waterlogging area in the surface water collection system can play a significant role in management and control urban runoff. One of the most powerful rainfall-runoff modeling tools is the SWMM model. The aim of this research is to evaluate the changes in land cover and urban development on runoff peak in Shahrood city. In this research, using of ArcGIS and Google Earth software, a land cover map including green area, road network, building area, sloping areas and bare land, for the years 2003 and 2022, were prepared and their changes analyzed. After preparing the required information, the SWMM model was used to simulate the runoff. By using four rainfall events, the model was calibrated and verified and the efficiency of the model was evaluated with RMSE and KGE indicator. The model was implemented using the Precipitation plan, with the concentration time of area which was calculated in 30 minutes, for the years 2003 and 2022 and the return period of 5, 10, 25 and 50 years. According to the evaluation performed in the SWMM model, the RMSE and KGE index showed good performance for four precipitation events, for example, the KGE index was obtained as 0.91 for calibration and value greater than 0.66 for validation. The urban development over the 20 years period resulted in 1.8 percent increase in the impervious surface and a decrease of 6.9 percent of the permeable surface, with road network accounting highest increasing by 22.2%, and decreasing of 18.2% the green area, leading to loss of recreational surfaces such as parks and urban woods. The runoff simulation results showed that the location of the canals and nodes in 2003 and 2022, which were prone to flooding, were almost the same which can indicate to the lack of proper planning in flood management and the design of the water collection system in the city. Finally, it can be concluded that the unsustainable and imbalanced urban development of the cityand the increase of impervious areas during the years 2003-2022 will lead to an increase in flood events thereafter by resulting runoff peak increasing, all these will lead to heavy economic damage and human losses in the city.