Rainwater Harvesting and Reuse: A Preliminary Review

Today, available water resources are under severe pressure on a global scale due to demographic, economic, and social demands, environmental and climate changes, and technological challenges. It is well known that rainwater harvesting (RWH), a simple and ancient method, has the potential to integrate surface and groundwater resources in areas with inadequate water supplies. Since their inception, the temporal and partial availability ofwater resources, particularly in southern regions, has triggered the development of various water systems for RWH and storage. Since then, technologies for the construction and operation of multiple types of cisterns and other relevant hydraulic structures have evolved. Significant achievements in RWH and use from the dawn of humankind to the present are analyzed. The Indo-European and Roman periods are highlighted as examples of outstanding achievements. The primary need for water justifies not only the innovations found throughout history but also the most advanced level of engineering of each era used in these constructions. In addition, the significance of this hydraulic technology and understanding the value of water conservation in the present and future are considered. Hygienic precautions to ensure the purity of the water collected and stored is another aspect that deserves further study. This preliminary research will provide a systematic overview of the state of the art. In recent decades, many countries have supported the updated implementation of this practice to cope with increasing water demand and to reduce the frequency, peak, and volume of urban runoff. These considerations motivate an interest in examining the current situation and prospects for further development of this method worldwide. This paper aims to analyze the current situation of RWH as an alternative water source to address water scarcity in various countries.