Environmental Services

Rain Gardens


U. S. EPA video!  Reduce Runoff: Slow it Down, Spread it out, Soak it in  Learn about rain gardens, rain barrels, and more!


Check out these rain garden projects!

• McKinley Elementary School Rain Garden

•  The Arlington Condo

•  Powhatan Spring’s Children’s Rain Garden 

What is a Rain Garden?   

A "rain garden" is a man-made depression in the ground that is used as a landscape tool to reduce runoff and improve water quality. The rain garden forms a "bioretention area." It collects water runoff and stores it, permitting it to be filtered and slowly absorbed by the soil. The bioretention concept is based on the hydrologic function of forest habitat, in which the forest produces a spongy layer that soaks up water and allows it to slowly penetrate the soil layer.




Are you installing a rain garden and need mulch? The County has mulch available for its residents.

Benefits of Rain Garden

Rain gardens should be strategically located to intercept water runoff. They improve water quality by filtering out nutrients from rain water that runs off your driveway or roof. The first flush of rain water ponds in the rain garden, and contains the highest concentration of materials washed off impervious surfaces such as roofs, roads, and parking lots. The water-loving plants in the rain garden absorb rain water and reduce problems with excess water and ponding in your yard.

A properly designed rain garden will not retain water long enough for mosquito reproduction. Standing water almost always soaks into the group within a few hours and often within a matter of minutes. Mosquitoes require seven days to complete their life cycle in standing water. If water remains for a matter of days in your rain garden, the soil may have a high clay content or may be compacted. These problems can be remedied by loosening and adding humus or mulch in the upper 6 to 18 inches of soil.

Rain Garden Resources

Last Modified: August 16, 2013
2100 Clarendon Blvd. Arlington, VA 22201 Tel: 703-228-3000 TTY: 703-228-4611