Assessment of the Drainage Network Systems and Their Effects on Stormwater Flow and Flooding in Orogun, Ughelli North, Delta State, Nigeria

Flooding has become a recurring environmental challenge in many Nigerian urban centers, with Orogun town in Ughelli North Local Government Area of Delta State experiencing increasing vulnerability to stormwater inundation. This study assesses the drainage network and its effects on stormwater flow and flooding in Orogun, employing a quantitative research methodology that integrates field surveys, hydrological measurements, and geospatial analysis. The research evaluates drainage network characteristics including drainage density, stream order, channel morphology, and hydraulic capacity, while also examining the impacts of anthropogenic activities such as waste disposal, encroachment on floodplains, and inadequate drainage infrastructure maintenance. Findings reveal that Orogun possesses a dendritic drainage pattern with drainage density of 2.18 km/km² and stream order of 4, indicating moderate natural drainage capacity that has been significantly compromised by human interventions. Blocked drainage channels, undersized culverts, and poor solid waste management practices were identified as major contributors to reduced hydraulic efficiency and increased flood risk. The study recommends immediate drainage channel clearing and desilting, enforcement of waste management regulations, expansion of critical crossing structures, and development of a comprehensive stormwater management plan for Orogun. These findings contribute to the growing body of knowledge on urban flood management in the Niger Delta region and provide practical recommendations for policymakers and urban planners.