Rain Gardens

Rain gardens offer an attractive way to decrease stormwater runoff and recharge groundwater.  For the homeowner, a rain garden can simply be a shallow, landscaped depression in the yard, positioned to capture stormwater runoff.  Rain gardens planted with native, water-tolerant plants provide excellent wildlife habitat.  By capturing stormwater runoff, rain gardens reduce the amount of polluted stormwater reaching streams and promote groundwater infiltration.

 

Above Left: ClearWater's rain garden.  Above Right: The site before the garden.

Located at the rear of our building, the rain garden is placed to capture stormwater that runs off of Atherton Street and our parking area.  The area was previously gravel and asphalt.  The gravel area was approximately 400 square feet.  Approximately 1,000 square feet of asphalt were removed by Hawbaker to make way for the rain garden.  The rain garden was planted with native plants by a crew of volunteers.  View a list of the plants we used in the rain garden.

Although community and commercial rain gardens can be highly engineered, a home rain garden is simple to create. 

 

Step #1:  Choose a site for the rain garden

Observing the path of stormwater runoff during a storm will help determine potential sites for a rain garden.   To capture stormwater runoff, place the rain garden between the source of runoff and the nearest storm drain. Consider placing the rain garden near a downspout to capture rooftop runoff.  To keep water away from basements and foundations, the rain garden should be placed at least ten feet from the house.  Another option is to place the rain garden to capture runoff from a sidewalk, parking lot, or driveway.

 

Step #2:  Prepare the rain garden bed

After the site is selected, the next step is to dig a shallow basin for the rain garden.  Rain gardens can be as shallow as a few inches, or as deep as a foot.  They can be of any size, so long as the size corresponds to the amount of stormwater directed to the rain garden.  To test how the rain garden will handle water, run a hose into the rain garden, then make necessary adjustments.  Heavy clay soils may need to be amended with compost to increase their ability to absorb water.

 

Step #3:  Plant the rain garden

Plants used in the rain garden must be water tolerant, but also be able to survive dry periods.  Using native plants will provide the best habitat for wildlife and require the least maintenance.  Grasses, flowering perennials, and shrubs can all be used in rain gardens.  (See sidebar for a list of plants appropriate for rain gardens and native to the Mid-Atlantic.) 

 

Step #4:  Maintain the rain garden

Once the plants are installed, maintenance is like that for any other garden, including mulching, watering during drought as the plants are getting established, and weeding.

 

DNR Rain Garden Manual for Homeowners

(Wisconsin Department of Natural Resources)

www.dnr.state.wi.us/org/water/wm/dsfm/shore/documents/rgmanual.pdf

 

How to Build a Rain Garden

(Dane County Lakes and Watershed Commission)

www.co.dane.wi.us/commissions/lakes/pdf/HowToBuildaGarden.pdf

 

How to Install a Rain Garden

(South River Federation and the Center for Watershed Stewardship)