DESIGN OF A STORM WATER DRAINAGE SYSTEM

ABSTRACT

Designing a good drainage system to manage storm-water in the city of Asaba is really important. The primary aim of this study is to design an efficient storm-water system for the city of Asaba that can effectively mitigate the risks of localized flooding, safeguard properties and promote urban development. This study methodology encompasses different stages. The first step involved was conducting a comprehensive engineering survey to map out the project area, pinpoint vulnerable areas and ascertain optimal locations for the drainage system. Rainfall data of over 25 years was obtained to give an insight of the rainfall patterns after which a homogeneity test was conducted to validate the consistency and reliability of the rainfall data. Since the homogeneity test proved the rainfall data is of the same probability distribution, rainfall intensity and return period were calculated which served as the bedrock for subsequent hydrological analysis. An IDF curve with a return period of 10 years was developed which served as an indispensable tool for the design of resilient drainage system. The IDF curve served as a tool in determining the peak discharge of the catchment area. The results obtained from this study include the rainfall intensity of various durations, IDF curve for a return period of 10 years and a knowledge of the peak discharge of the study area. Knowing the peak discharge of the catchment area, hydraulic analysis was performed and a storm-water drainage system that exhibits robust capacity and efficiency was designed to standard which would help mitigating the risk of flooding during intense rainfall events.