Lade OOloke D2022-07-232022-07-23202010.1016/B978-0-12-816120-3.00014-2https://nerd.ethesis.ng/handle/123456789/81Rainwater harvesting systems (RWHS) can augment water supply to meet urban and rural needs with added financial benefits. This study assessed the hydraulic and financial performance of a RWHS for three case studies: hospital, residential and office block in Ibadan. Storage capacity, water savings and payback period were optimized using a rain-cycle model. A comprehensive assessment of the proposed system was carried out which considered seven specified and eleven unpredictable variables. The result of maximizing storage capacity and water reduction found that 78.1 percent, 70.6 percent and 75.0 percent of demand could be met by a 12 m3 tank (hospital), 4 m3 tank (residential) and 10 m3 tank (office) with an estimated savings of $51,072, $259 and $2,564 over 50 years and a payback period of 1, 21 and 8 years respectively. Therefore, the potential to use RWHS as an alternative source of water for the hospital and office block are higher than for residential purposes.enMonte Carlo simulationRain cycle modelRainwater harvestingWater savingEfficiencyPayback periodArticle