Rain Gardens

Rain gardens are landscaped areas planted with wild flowers and other native vegetation that collect stormwater runoff from rooftops, driveways, lawns and parking lots and allow it to soak into the ground. The rain garden fills with a few inches of water after a storm and the water slowly filters into the ground rather that running off to a storm drain. If rain garden is build a downspout in the front yard of a typical quarter- acre-lot, the annual runoff from that lot will be reduced about 25 percent.

Pollutants such as sediment, fertilizer, pesticides and even oil, grease and heavy metals from the roads are trapped by the soil and root systems, allowing clean water to infiltrate the subsoil and recharge the groundwater. Rain gardens also create habitat for wildlife. Below the surface of the garden, a number of processes are occurring that mimic the hydrologic action of a healthy productive forest. The garden acts as a small bio retention cell where storm water is cleaned and reduced in volume once it enters the rain garden. Rain gardens are simply low-lying, vegetated shallow depression that’s planted with native wetland or wet-prairie wildflowers and grasses.

RAIN GARDENS: A HOW TO MANUAL FOR HOMEOWNERS
More information at UW Extension