Protecting The Environment From Urban Water Cycle Disruption
Most urban areas are built in such a way that when it rains, all of the water is directed immediately into storm sewers via gutters, curbs, and ditches and then out into nearby creeks and streams. On its way to the storm water system, the rain water picks up pollutants such as motor oil, grease, pet waste, fertilizers from lawns, and other toxic substances. The water then rushes out all at once from storm sewers, severely eroding the banks of the creeks it is directed into and bringing all of the pollutants from the city into the water. This is called non-point source pollution.
A rain garden is a garden with a shallow depression which is strategically located in a landscape to capture storm water runoff from impervious surfaces, such as rooftops, patios, driveways, and parking lots, before it enters the storm water system. The water is held by the garden and allowed to slowly infiltrate the soil. The soil and plant roots improve water quality by filtering pollutants, the overall amount of storm water runoff is reduced, and the groundwater supply is recharged.
Rain gardens don't need to be planted with water-loving plants. Because they drain quickly (24-48 hours), the plants only have to be able to tolerate lots of water for short periods, but they also need to be able to withstand periods of drought. Different areas of your garden can be planted with different kinds of plants. For example, the berm won't be receiving as much water as the low-lying middle, so native arid plants would do better there. Ask your local native plant nursery for suggestions. Remember to consider plant height, wildlife attraction, flowering, and sun/shade tolerance when choosing your plants.
Native plants are ideal for landscaping for many reasons. Because they have adapted to your area's climate over time, they don't need chemicals to help them grow, can tolerate your high and low temperatures, have very deep roots for drought resistance, have defenses against harmful native insects, and serve as habitats for native wildlife. The deep roots of native plants also makes them ideal for rain gardens because they create channels in the soil which allow water to soak in quickly.
Local Landscape Contractors
If you would rather hire someone to build your rain garden, look for a landscape association in your state for the names of local landscape architectural firms, or the Yellow Pages (www.yellowpages.com) under Landscape Architects or Landscape Contractors. Not all landscapers are experienced in building rain gardens so ask questions to be sure you're hiring someone who will build you a quality rain garden.
Other sources for information:
- Your local Cooperative Extension Service
- Internet search engines list hundreds of sites…here are a few:
- "Rain Gardens - Managing Water Sustainably in the Garden and Designed Landscape" by Nigel Dunnett & Andy Clayden
- "The Blue Thumb Guide to Raingardens" by Rusty Schmidt & David Dods Dan Shaw
- "The Rain Garden Planner" by Terry Wallace
- "Rain Gardening in the South" by Helen Kraus & Anne Spafford
Please continue to support NGC's Water Conservation Platform by promoting public and private rain garden installations in your state, club programs, and educational exhibits.
For more information, contact:
Garnet Ascher, Chairman: NGC Rain Gardens