Only around one percent of water is currently easily accessible for human needs. This has encouraged a search for solutions to fight local scarcity. One proposed answer is the collection of rainfall through Rain Water Harvesting (RWH) methods. The process consists of collection, storage, and local use of rainwater. RWH systems can be sub-categorised based on the catchment size, runoff transfer distance, source of water, mode of storage, mode of usage, and other details. As an integral part of human settlements and farming for thousands of years, RWH methods present a number of benefits if suitably applied, namely, diversification with better yields that can increase income, create a number of jobs, reduce poverty level, promote sustainable forms of agriculture, mitigate climate change and spread year-round vegetation cover. However, the benefits of these systems come with certain challenges: most notably the provision of a high quality and sufficient quantity of water with feasible measures. In this paper, challenges have been divided into technical and quality issues, legislative, economical aspects and lack of awareness. In order to help tackle the above mentioned challenges, as well as to promote and scale-up the usage of RWH systems, the Gansu Province case in China and the North-eastern region of Brazil are presented in an exemplary way as best practices.