What is a rain garden?
Rain gardens are a form of Low Impact Development (LID). They are small planted landscape depressions that mimic the natural hydrology that existed before construction of man-made features. These rain gardens are designed to capture stormwater runoff from the 2-year storm event and allow it to infiltrate into the subsoil and transpire into the atmosphere through the native plant foliage. Rain gardens slow down runoff, alleviating localized flooding, pollution, and stream channel degradation. They improve water quality and increase curb appeal to homes and businesses. Read more about rain gardens here: http://bit.ly/1mLtn46
1. Shelby County receives an average of 54.7” of rainfall per year. Most of this water ends up in local waterways after picking up a wide range of heavy metals, soil particles, bacteria and other pollutants from various surfaces.
2. These rain gardens are designed to capture and cleanse the first 1" of stormwater runoff that typically contain the most pollutants from the surrounding roof areas.
3. Native plants help to filter pollutants from stormwater while their roots help keep soils in place as water flows through the rain garden.
4. The 20" deep layer of sandy planting soil provides nourishment for plants while allowing the stormwater to slowly percolate down to a 12" layer of rock at the bottom of the rain garden. The 12" layer of rock has many small void spaces that cumulatively provide additional storage space to hold the water before it infiltrates into the subsoil below.
5. By the time the stormwater has been filtered by the native plants and the sandy soil media, it is much cleaner and cooler in temperature than it would be by utilizing traditional stormwater management techniques. Both of these water quality characteristics are important to minimizing the impact of stormwater runoff on the environment.
What do rain gardens do?
Bill Landry of "The Heartland Series" explains what rain gardens are and what they do in this video: http://bit.ly/1QMReNx
How do I install a rain garden at my house?
Guide to installing rain gardens at your house (Nashville guide): http://bit.ly/1GoxBbI
Video on how to install a rain garden: http://bit.ly/1Hsw1I1
Workbook for you to draw your garden: http://bit.ly/1BZoMRM
What native plants do I choose for TN?
Native plant guide for rain gardens in West Tennessee: http://bit.ly/1JmTx5w
Plants for rain gardens need to be able to withstand brief periods of standing water yet be able to tolerate extended periods of dryness. While there are a number of plants that can do well under these conditions, the best are those native to our region. Native plants have evolved to thrive in our local environment and provide great habitat for beneficial insects, including bees and butterflies.
How do I maintain my garden?
A guide to maintaining the garden, Portland: http://bit.ly/1EI5X6Y
Other helpful links:
To learn more about the LID projects the Memphis-Shelby County Office of Sustainability has done, please visit: www.sustainableshelby.com/LID
For pictures from the rain garden installation, visit our facebook page.