What is a rain garden?
A rain garden is a garden of native shrubs, perennials, and flowers planted in a small depression, which is generally formed on a natural slope. It is designed to temporarily hold and soak in rain water runoff that flows from roofs, driveways, patios or lawns.
Rain gardens are effective in removing up to 90% of nutrients and chemicals and up to 80% of sediments from the rainwater runoff. Compared to conventional lawn, rain gardens allow for 30% more water to soak into the ground.
What benefits do rain gardens provide to my community?
- Improve water quality by filtering out pollutants
- Aesthetically pleasing
- Preserves native vegetation
- Provides localized stormwater and flood control
- Attracts beneficial birds, butterflies, and insects
- Easy to maintain after establishment
- Opportunity to raise water quality awareness in your community
How much does it cost to design and install a rain garden?
The cost of a rain garden is dependent on the property’s soil type, the size of roof/driveway/patio draining into a rain garden, and the types of plants chosen. If the soil is high in clay content it may be a good idea to install an under drain system to prevent standing water in the rain garden for more than 48 hours.
For a self-built rain garden expect to pay between $3 and $5 per square foot in plant costs and soil amendments. Digging the garden is the most time consuming task, as 6-8 inches of soil depth is typically removed to add amendments.
When working with a landscaping company to design and install a rain garden, the cost will significantly increase to around $10 to $12 per square foot.
What type of maintenance is required?
Rain gardens do not require fertilizer if native vegetation is used. During the first few years after installation of a rain garden, the weeds will need to be removed periodically. After the plants in the rain garden have become established and grown larger, they will eventually out-compete the weeds.
Thinking of Installing a Rain Garden? Let us know! We’d be interested in your comments, the success of your garden, and pictures. Please send information to your stormwater representative in your local community.