In a study on stormwater management in urban areas in South Africa, researchers investigated how green roofs can reduce runoff during rainstorms. By analyzing data from various storm events in the eThekwini region and using a computer model, they found that green roofs significantly decrease stormwater flow rates and volumes. The best green roof model reduced peak flow rates by over 40% compared to conventional roofs. The amount of water retained on these green roofs depended on how hard and long it rained. This means that using green roofs in South Africa's urban areas, like the eThekwini Central Business District, can help reduce flooding and manage stormwater effectively.