RAIN GARDENS: A WATER POLLUTION SOLUTION

Rainwater runoff from your roof, driveway, sidewalk and yard flows straight to the nearest storm drain. Many toxic lawn and garden chemicals, heavy metals, oils, pet waste, salts and dangerous particulate matter are mixed with the rainwater and sewage as it is washed into water treatment facilities, creeks, rivers, lakes and wetlands.  In areas of older infrastructure, combined sewer systems can result in storm water overloading sewer pipes and mixing with untreated sewage.  Pollutants in the water runoff put undue stress on birds, amphibians, animals and insects that inhabit water environments, tipping the fragile balance of nature.  In the natural world, rainwater movement is slowed and captured by thick vegetation, depressions and wetlands.  In urban environments however, impervious surfaces such as roofs, sidewalks, driveways, parking lots and roads accelerate water flow, and channel rainwater into creeks and rivers faster than the areas can naturally hold, promoting soil erosion and loss of ecological diversity.  Capturing and recycling rainwater runoff from your property contributes to soil, water and wildlife conservation efforts, reduces flash flooding and can even save you money.  Rain Gardens are truly a beautiful and functional solution to capturing rainwater.

Rain gardens are simply shallow basins tilled or dug into the ground typically 8”-12” deep, and amended with a mix of sand, compost and/or native soil.  These shallow basins are most often sited on areas of the yard where rainwater runoff is most prevalent, such as a swale or downspout runoff area, and typically range in size from 100 to 300 square feet.  The rain garden should be located at least 10 feet from the home to prevent leaks into the basement or crawl space.  Like a sponge, rain gardens mimic the natural absorption and pollutant removal abilities of woodlands, prairies and wetlands, and capture as much as 30%-40% more rain water than an average lawn.  A properly designed rain garden can trap, retain and break down 99% of common pollutants from urban storm water runoff into less harmful compounds according to the American Chemical Society journal, Environmental Science and Technology.  

Planting the rain garden is even more exciting than building it.  Many native Ohio perennials, grasses, shrubs and trees are adapted to rain gardens, and remain low maintenance once established.  Many native plants can tolerate both wet and dry conditions, making them perfect candidates for the rain garden.  Ohio native plants increase habitat and food sources for birds, butterflies and other beneficial insects that eliminate pest insects.  Just as with any garden area, select rain garden plants based on sunlight exposure. Many Ohio native plants are adapted to shade as well as sun, so rain gardens can be built in both sun or shade locations with great success. Always consider using plant varieties of varying height, shapes and textures that bloom, bear fruit or interesting bark through the seasons.  Like most gardens, rain gardens will need to be weeded, watered and mulched with erosion resistant double shredded hardwood until plants are fully established and filled in, usually within1-3 years. 

Rain gardens are also considered mosquito death traps.  This is due largely to the fact that they are designed to drain within 24-48 hours.  Thus, the water drains before the mosquito eggs have time to mature into larvae, drying them out and destroying them.  Compost helps to promote better drainage in the rain garden, and plant roots do an incredible job of absorbing rainwater and creating channels for water to drain deeply into the soil.  Downspouts can be piped directly into the rain garden to further reduce the chance of storm water runoff, and eliminate dumping excess water onto your neighbors property.    Because rain gardens are so effective at capturing storm water runoff, they reduce the amount of irrigation needed to sustain the garden, saving both time and money.

Building and planting a rain garden on your property is one of the most ecologically sound practices we can take part in to help prevent soils erosion, water pollution and promote wildlife biodiversity.  When we build rain gardens, we not only promote environmentally sound conservation methods, but also create beautiful gardens that will in time sustain themselves with minimal care.  For more information on rain gardens, or to make donations to promote rain garden awareness, please visit the Greater Cincinnati Rain Garden Alliance website at www.millcreekwatershed.org , a program of the Mill Creek Watershed Council of Communities, a nonprofit organization.  Also, if you are interested in having your very own rain garden installed and planted in your yard or community, please contact wes@marvinsorganicgardens.com or call 513-932-3319 for a free estimate.