The intent of rainwater harvesting is to capture the rain where it falls for use in the future. Like Keyline Planning or Holistic Planned Grazing, rainwater harvesting establishes an effective water cycle through earthworks or other man-made infrastructure, such as rain barrels or rainwater cisterns. This process mimics healthy ecosystems by spreading and infiltrating water into the soil, which then improves soil carbon levels and soil water holding capacity through the hydration of soil organic matter.
Rainwater harvesting is, in many ways, the opposite of conventional development practices. Rather than impervious hardscapes, such as asphalt and concrete, rainwater harvesting promotes certain best management practices (BMPs) that offer a multitude of benefits, from Stormwater Quality to Flood Hazard Mitigation, by integrating strategies for creating localized catchments designed to permeate and enhance green open space landscapes, such as yards, gardens, urban farms, parks, and golf courses. These are small-scale, low-cost strategies that have the ability to decrease erosion, reduce flooding, minimize water pollution, and prevent mosquito breeding.