It is seen that plain, sloping roofs, such as those made of metal or plastic, make it possible to collect up to 50% more rainwater than flat, rough ones. The information was obtained between 2008 and 2010 using four types of roofs on the university campus: three sloping roofs (tiled with metal and polycarbonate sheets) and one flat gravel roof.
Water obtained from the sloping roofs was better in terms of physical and chemical quality compared to the water collected from the gravel roof. This can be seen in practically all the parameters (conductivity, total organic carbon and carbonates). In the water from gravel roofs, greater meteorisation, depositioning of particles and colonisation by plants were observed.
According to the study, the results are of “importance” for local governments and urban planners in designing buildings and cities from the perspective of sustainable rainwater management. With the appropriate filtering and treatment, the resulting water can be used to wash floors and vehicles, water gardens, streets and even for filling cisterns or washing machines.