Abstract
Erbil has been undergoing rapid urbanisation and population growth for the last ten years. The impervious surface areas increased, so the volume of runoff generated from stormwater increased. For this reason, the storm sewer system is faced with additional runoff from the urban areas, and the existing sewer system is inadequate. This study focuses on the storm sewer system design using SewerGEMS and AutoCAD Software in Mass City, which is located in the east of Erbil. The topographic map of the study area was created using Civil 3D software and the total station in surveying, and rainfall storm data were collected from Erbil Meteorology Station and the General Directorate of Water and Sewage. Geometric design and hydraulic modelling were done using AutoCAD and SewerGEMS, respectively. The results show hydraulic design parameters such as flow velocity, sewer pipe size, slopes, manholes, pipe profiles, hydraulic grade line, minimum depth of excavation, and the minimum number of drops. Such a model allowed the project to be accomplished in a short time, with high efficiency and low costs; the model effectively demonstrated its ability to improve design and analysis by examining hydraulic performance.