Rainwater harvesting collects and stores roof runoff for uses like landscape irrigation or indoor potable water, providing a sustainable, free water source. Systems range from simple rain barrels to large cisterns with filtration and pumps. Key benefits include reducing water bills, reducing stormwater runoff, and having a resilient, high-quality water supply.

Rainwater harvesting involves collecting rain from surfaces (catchment) for immediate use or recharging groundwater. Primary methods include rooftop harvesting (storing water in tanks for domestic use) and surface runoff harvesting (collecting ground runoff for irrigation or groundwater recharge)