. O.C. Izinyon,

Benin City, Edo State, faces increasing urban flooding and water scarcity due to rapid urbanization and limited public water supply. Rainwater harvesting (RWH) offers a sustainable solution by reducing surface runoff and supplementing household water demand. This study investigates the effectiveness of RWH as a stormwater management strategy, evaluates current practices, and explores its potential to improve water availability and mitigate flooding in selected locations within Benin City. A combination of field surveys, photographic documentation, household questionnaires, interviews, hydrological assessments, and case study reviews was employed. Field surveys focused on Upper Sakponba, Eyean Community, and Amagba Road, examining rooftop collection systems, storage tanks, and compound management such as grassing. Questionnaires assessed household awareness, adoption, and perceived benefits of RWH. Hydrological analysis using the Rational Method estimated rooftop runoff volumes, while Lagos case studies provided insights into large-scale RWH integration with green infrastructure and flood mitigation systems. Results show that many households practice RWH using plastic or concrete tanks, which reduces runoff and meets non-potable water demand, although adoption is limited by cost, technical knowledge, and space. Hydrological assessment confirmed that rooftop runoff can satisfy household water needs when storage is properly sized. The study recommends incorporating RWH into building codes, providing subsidies and technical training, promoting first-flush diverters and filtration units, and integrating RWH with urban stormwater measures such as retention ponds and green infrastructure