<p>This study presents the development and implementation of a rainwater harvesting system (RHS) as a Testbed in Sejong City, South Korea, aimed at addressing water scarcity by promoting rainwater as a sustainable source of drinking water. The system, designed to collect rainwater from a 200&#xa0;m² roof area with an average annual rainfall of 1200&#xa0;mm, is capable of collecting approximately 216,000&#xa0;L of rainwater annually. To ensure water quality, a multi-stage filtration and UV disinfection process was implemented. Remote monitoring and control through a Supervisory Control and Data Acquisition system were incorporated to track water quality parameters such as pH, water level, and electrical conductivity in real-time, ensuring the safety of the collected water for drinking purposes. The system achieved significant reductions in microbial contaminants, with general bacteria levels dropping from 6270 CFU/ml in untreated rainwater to 80 CFU/ml after treatment, meeting WHO drinking water standards. Additionally, the study highlights the economic feasibility of the RHS, showing potential cost savings through the use of local materials and labor. This research supports the achievement of Sustainable Development Goal 6 (SDG6), which aims to ensure the availability and sustainable management of water and sanitation for all. By demonstrating that rainwater can serve as a reliable, eco-friendly alternative to traditional water sources, particularly in developing countries where access to clean water is limited, this system offers a sustainable and scalable solution to global water challenges. The successful integration of technical, economic, and social aspects ensures that the RHS contributes to both environmental sustainability and social equity, helping to advance SDG6 in regions facing water scarcity.</p>