Rain Gardens: Treating Runoff at the Source
What are Rain Gardens?
Rain gardens are shallow depressions in the landscape that capture runoff from streets, driveways, rooftops and other hard surfaces. The runoff that flows into the garden soaks into the ground where it is filtered by soil and plants Rain gardens are designed to be dry within 24 hours after the rain stops so they don’t harm plants or breed mosquitoes.
How do They Work?
Rain gardens are mini water purification factories that run on robust ecological neighborhoods of native plants. The process begins above the soil with these plants and their flowers then moves below ground where the process is completed. Above the soil the plants filter out debris and provide habitat for organisms that help break down pollutants. Below ground, roots pull water and nutrients out of the soil and tiny biota help break down the leftovers. Healthy plant communities are good at removing nutrients and pollutants in stormwater.
Benefits to Your Property
Rain gardens are very similar to typical decorative gardens. Just like professional landscaping, rain gardens add to the curb appeal of your home, and can even increase your property value! As different plants bloom throughout the year, you will be treated to a variety of vibrant colors.
Benefits to the Environment
Stormwater runoff in urban/suburban areas is typically captured in storm drains and sent untreated to nearby lakes and streams. This means that everything from grass clippings and fertilizer to oil and pet waste get washed down the drain and end up in our local waterbodies. Serious problems can result; including algae blooms, dangerous bacteria, and a sick or dying aquatic community. In addition, the large amount of water going into the stormwater system causes erosion problems to our neighbors downstream.
Rain gardens work to correct all of these issues by capturing runoff near the source and allowing the water to soak into the ground. The water is filtered by the plants and soil allowing it to enter our lakes and streams naturally as clean, cool groundwater. It also helps replenish our groundwater supplies.