iarjetIARJETIARJET2708-5163https://doi.org/10.47310/iarjet.2021.v02i01.006Runoff Estimation and Storm Drain Design in Variable Urban Catchments: A Case Study from Khartoum City, SudanInsafS.BabikerMohamedAbugaib A.MohamedDepartment of Social Studies Faculty of Arts King Faisal University Al-Ahsa, Saudi ArabiaDepartment of Environmental Engineering College of Water and Environmental Engineering Sudan University of Science and Technology Khartoum, SudanRealistic runoff estimates are crucial for accurate design of storm water drainage systems, particularly in developing urban catchments which are prone to overland flow and street inundation following extreme rain storms. Khartoum, capital of Sudan, as many cities of the developing countries, lacks proper storm water drainage system. Local government is however, spending efforts to plan and design several storm drains in attempt to mitigate the problem of urban flooding during rainy season. This paper aims to estimate surface runoff in order to design a proposed storm drain in west central Khartoum. Long-term rainfall intensity data was analyzed in order to produce Intensity-Duration-Frequency curves. The Rational model was used for runoff estimation and Manning formula for storm drain design. Geographical information system was used to visualize surface and topographic data and to obtain catchment characteristics. The storm drain was sub-divided into five sectors and the maximum calculated peak runoff was 3.17m3/s based on rainfall intensity of 10-year return period. The proposed drain design was rectangular in shape with a maximum cross sectional area equal to 3.3m2 (1.65 x 2m). Challenges to planning sustainable stormwater structures in Khartoum City were attributed to climate variability, urban development and change in surface conditions.