This document discusses rainwater harvesting (RWH) systems. It defines RWH as collecting and storing runoff from rainfall for immediate or later use. The key components of an RWH system are a roof, gutter system, cistern, and additional filters and pumps for indoor use. RWH provides benefits like water conservation, reduced costs, and an alternative water source. With an average-sized home of 2,500 square feet and 32 inches of annual rainfall, about 42,400 gallons could be collected annually. The total cost of a home RWH system is approximately $8,500.