Rain Garden

Rain gardens, also called bioretention facilities, are one of a variety of practices designed to increase reabsorption of rain runoff by the soil. They can also be used to treat polluted stormwater runoff. Rain gardens are designed landscape sites that reduce the flow rate, total quantity, and pollutant load of runoff from impervious urban areas like roofs, driveways, walkways, parking lots, and c... (Wikipedia)