What is a Rain Garden?
A rain garden is a landscaped, shallow depression in your lawn designed to collect stormwater from your roof, driveway, or other impervious surface before it reaches the nearest storm drain or waterbody.
By trapping stormwater and allowing it to seep naturally into the ground, rain gardens minimize runoff, remove pollutants, reduce flooding, and help recharge groundwater supplies.
In addition to their value in preventing stormwater pollution, rain gardens are typically planted with native shrubs or perennials, adding beauty to your lawn and providing habitat for birds, butterflies, and beneficial insects.
Rain Gardens Are Not Bioretention
You may be familiar with the term bioretention as a stormwater management technique. Although rain gardens and bioretention basins function similarly, they are very different! Bioretention basins require detailed engineering, and are usually much larger with sophisticated conveyance devices (e.g., underdrains, overflow structures, etc.) and a prescribed soil mix to promote filtration by stormwater. Bioretention is often used when managing stormwater at new development projects or retrofits. Rain gardens are small in scale—ideal to manage runoff from smaller drainage areas such as residential rooftops and driveways—and utilize native, or modestly amended soils. Proper rain garden design may be achieved through appropriate site selection and simple sizing techniques.