About
A rain garden is a landscaped depression that captures rainwater runoff from roofs, driveways, streets, or parking lots. Runoff captured in a rain garden is temporarily ponded before infiltrating and percolating down through the natural soils. This allows for plants to use the water and for pollutants to be filtered out. Rain gardens can come in many shapes and forms to add an attractive feature to a landscape while also serving a real function helping to manage and treat stormwater runoff.
Benefits
Installing a rain garden helps restore a landscape's ability to manage water more sustainably. Historically, the prairies and savannas of Iowa held and infiltrated most rainfall, and surface runoff was rare. Rainfall was absorbed and moved down through the soil to become groundwater flow. Cool, clean groundwater fed and maintained rivers, streams, wetlands, and lakes.
Today our impervious and compacted urban surfaces shed dirty runoff with almost every rain. This dirty runoff goes to receiving streams, which causes water quality problems and contributes to flooding. Rain gardens help reduce runoff and protect water quality.