Why are rain gardens important?
As cities and suburbs grow and replace forests and agricultural land, increased stormwater runoff from impervious surfaces becomes a problem. Stormwater runoff from developed areas increases flooding; carries pollutants from streets, parking lots, and even lawns into local streams and lakes; and leads to costly municipal improvements in stormwater treatment structures.
By reducing stormwater runoff, rain gardens can be a valuable part of changing these trends. While an individual rain garden may seem like a small thing, collectively they produce substantial neighborhood and community environmental benefits. Rain gardens work for communities in several ways:
- Increasing the amount of water that filters into the ground, which recharges ground water;
- Helps protect communities from flooding and drainage problems;
- Helps protect streams and lakes from pollutants carried by stormwater runoff;
- Enhances the beauty of yards and neighborhoods;
- Provides habitat for insects, birds, and animals.
Designing a Rain Garden
Rain gardens can be located just about anywhere on a landscape, but here are some guidelines to help you select the right place:
- You will want to look for a place that the rain garden will catch runoff. It is usually a low-laying area.
- Place the garden at least ten feet from a building foundation to prevent structural damage from flooding and wetness.
- Areas where there are water puddles long enough to form small ponds are not ideal. The infiltration of the soil is already low, and adding a garden will make it worse.
- Place the garden in full, or immediate, sunlight. This will speed up drying, decrease pathogens, and promote plant growth.
- Choose a relatively flat section of land that has well drained soil. This will make digging easier.
When you go to design your garden, you can do just about anything. They can be just about any shape or size. A lot of rain garden designs are in the shape of a kidney bean, with the largest side facing the source of the runoff. However, shape is not critical. Use your imagination. But, before you start digging call your local utilities to make sure that your garden will not interfere with electric, gas, phone, or water lines.
If you need a little help coming up with a rain garden design, the Stormwater Management Department has developed 6 different designs that will work with our local soils.