| Rain Gardens |
What is a Rain Garden?
Rain gardens are attractive, landscaped gardens built in depressions and planted with perennial native plants which enjoy getting their feet wet. They are designed to capture
and filter storm water runoff from impervious surfaces around the home, such as driveways and roofs.
Rain gardens serve multiple benefits and include their ability to perform the following functions:
 | Help keep water clean by filtering storm water runoff before it enters local waterways. |
| Help alleviate problems associated with flooding and drainage. |
| Enhance the beauty of individual lawns and communities. |
| Provide habitat and food for wildlife including birds and butterflies. |
| Recharge the ground water supply | |
Why Do We Need Rain Gardens?
The increase in development places more demands on our local environment. Impervious surfaces associated with development, such as driveways, roads and roofs, are
areas that cause runoff from the rain. Compacted soil from construction on development sites limits the ground's capacity to absorb water. Together, these factors reduce
the ability of our landscape to absorb and filter storm water.
As these impervious surfaces increase storm water runoff they can negatively affect our environment. This increases the chance for pollution to enter our waterways
through our storm drainage system and to flow untreated into our streams and lakes. This pollution is called nonpoint source pollution. Studies conducted by the United
States Environmental Protection Agency (USEPA) have shown that a substantial amount of the pollution in our streams, rivers and lakes is carried there by runoff from our
lawns and gardens. Some of the more common nonpoint pollutants include fertilizers, pesticides, pet wastes, grass clippings and yard debris. Rain gardens are an easy way
to help keep these pollutants out of our local waterways.
History of Rain Gardens
The first rain gardens were created to mimic the natural water retention areas that occurred naturally before development of an area. The rain gardens for residential use
were developed in 1990 in Prince George's County, Maryland, when Dick Brinker, a developer building a new housing subdivision had the idea to replace the traditional best
management practices (BMP) pond with a bioretention area. He approached Larry Coffman, the county's Associate Director for Programs and Planning in the Department
of Environmental Resources, with the idea. The result was the extensive use of rain gardens in Somerset, a residential subdivision which has a 300-400 ft. rain garden on
each house's property. This system proved to be highly cost-effective. Instead of a system of curbs, sidewalks, and gutters, which would have cost nearly $400,000, the
planted drainage swales cost $100,000 to install. This was also much more cost effective than building BMP ponds that could handle 2-, 10-, and 100-year storm events.
Flow monitoring done in later years showed that the rain gardens have resulted in a 75-80% reduction in stormwater runoff during a regular rainfall event.
(from: Wikipedia, the free encyclopedia)
Rain Garden Q's & A's
Does a rain garden form a pond?
NO! The rain water will soak in so the rain garden does not form a pond. If properly designed, they should hold water for a maximum of 48 hours.
Is a rain garden a breeding ground for mosquitoes?
NO! A common misconception of any water feature is that it will attract mosquitoes. However, mosquitoes need 7 to 12 days to lay and hatch eggs. A properly installed rain
garden should not hold water long enough for mosquito larvae to complete their life cycle. Rain gardens also attract dragonflies, which eat mosquitoes. Mosquitoes are more
likely to lay eggs in bird baths, storm sewers, and lawns that in sunny rain gardens. So a rain garden will not make a mosquito problem worse, and could possibly improve it
by helping to eliminate standing water.
Is a rain garden expensive?
It doesn't have to be! The main cost will be purchasing the plants, you can do the work yourself. If you hire a landscape consultant to design, construct, select and install
plants, the cost can increase greatly.
Is a rain garden hard to maintain?
NO! Rain gardens can be maintained with little effort after the plants are established. Some care may be needed the first two years and again in later years as the plants
mature. Native plants are well adapted to their natural surroundings and do not require fertilizers or pesticides.