Rain Gardens

Rain gardens are low-lying saucer-shaped garden areas that have absorbent soils, which temporarily collect stormwater runoff, usually from a roof, pavement, or other impervious surface, and allow it to slowly percolate into the soil. This provides flood control, groundwater recharge, and water-cooling benefits, while the plants, soils, and associated microorganisms remove many types of pollutants—such as pesticides, oils, metals, and other contaminants—from stormwater runoff.  When properly designed and maintained, rain gardens are attractive landscaping features that function like a natural moist garden, moist meadow, or light forest ecosystem.

Our man-made system of curbs, gutters, and stormdrains quickly carries stormwater runoff directly to local streams and rivers without any natural filtering process.  Studies by the US Environmental Protection Agency have determined that up to 70% of the pollution in our surface waters is carried there by stormwater runoff.  Much of that pollution comes from individuals and homeowners, due to yard care, yard waste, and chemical pollution from household activities.

Rain gardens serve several important functions in conservation landscaping. Stormwater pouring off hot roofs, pavement, and other impervious surfaces is temporarily captured, cooled, and allowed to percolate into the ground. This provides flood control, groundwater recharge, and water-cooling benefits. Stormwater is able to reach healthier temperature for fish and other wildlife by the time it slowly makes its way to the stream. In addition, this living filter system removes many types of pollutants from stormwater runoff.  Rain gardens also tend to become wildlife oases with colors, fragrances, and the sights and sounds of songbirds and butterflies regularly visiting your garden.

By creating a rain garden and keeping most of the rain that falls on your site contained on site—the way nature intended—you can help improve water quality in local streams, rivers, and ultimately the Chesapeake Bay. Rain gardens save water, reduce pollution, and help wildlife—all at the same time.

The GCWA installed the first functional, demonstrational rain garden in the George’s Creek watershed at Westmar High School in 2004.

                        For additional information on rain gardens, go to:
http://www.montgomerycountymd.gov/Content/DEP/Rainscapes/home.html