FACULTY OF ENGINEERING

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

This study is set out to evaluate the suitability of three Nigerian sand types, river, quarry, and coastal for mortar production, focusing on their impact on compressive strength and material properties, particularly the chloride content in coastal sand. The aim is to provide standardized data on local aggregates to enhance construction quality and sustainability in Nigeria, addressing the current lack of such data. A laboratory-based experimental design was conducted, employing standard methods to ensure reliability and repeatability. Six 50-mm mortar cubes per sand type were cast, cured, and tested for compressive strength at 7 and 28 days using a calibrated compression testing machine, following international standards (e.g., ASTM C109). The physical properties (e.g., particle size distribution, shape) and chemical properties (e.g., chloride content in coastal sand) of each sand type were analyzed using standard laboratory techniques, such as sieve analysis and chemical titration. All procedures were repeated to ensure consistency, with results analyzed at a 95% confidence level to assess their reliability.Coastal sand exhibited the highest compressive strength due to its well-graded particles, and low chloride content because it was desalinated, followed by quarry sand with slightly lower strength due to possible dust or angularity issues. River sand showed the lowest strength due to residual impurities, and grading which affected mortar integrity. The analysis identified the optimal sand type for mortar production and provided insights into the influence of material properties, with final data presented to determine statistical significance at the 95% conf dence level. Overall, the study aims to inform standardized guidelines for aggregate use in Nigeria, promoting cost effective and sustainable construction practices.