Recent failures in aging water distribution systems - Flint, MI, and Crystal City, TX - have demonstrated a need to rethink water infrastructure throughout the United States, and the world. Rainwater harvesting is one way to address this challenge. By taking advantage of local precipitation patterns, our solution aims to provide a safe and reliable water supply for homes across the world. Using proven statistical methods such as hidden Markov chains, RainMiner provides homeowners and urban planners with a powerful decision-making tool with direct applicability.