A rain garden is a designated section of a yard which would collect rainwater that pours from the rooftop of a house. This area would be off the lawns and driveways as it would get very soggy during heavy rains.

Generally, rain water gets drained in streams or other water bodies and carries a lot of pollutants along their way. But in a rain garden, the pollutants are deposited back into the soil. In fact, these gardens purify the storm water and separate the harmful substances.

The rain garden size depends on the drainage rate of the soil and also the area you can allot to capture the rain water. Sandy soils are the best to capture the water but other varieties of soil, except heavy clay are also suitable. Before creating the rain garden, test the permeability of the soil by filling it with water and noticing how long it could take to drain.

In addition to reducing flooding and pollution, rain garden reduce soil erosion as they stop gushing water and slowly release water supply to the surrounding plants. They also house a lot of butterflies and a variety of birds. They are very easy to maintain due to their wild nature as opposed to trimmed gardens and lawns.

A rain garden works on the concept of mimicking the nature. It is also called bio-retention gardens. This reduces runoff of water by designing landscapes that imitate natural filtering mechanisms which were removed during the course of human inhabitation in the natural land. These gardens do not house more than 5cm to 7cm of water. If the native soil has low filtration rate, a perforated drain system is put in place.

A depression is created and filled with plants which can handle a lot of water and would not get damaged easily even while over watering them. Some examples include certain wildflowers, ferns, shrubs, rushes, sedges and trees. They absorb a lot of water and release it slowly. They pick up contaminants like motor oils and fertilizers along the way.

It is very easy to set up a rain garden in your home. If you want to have more than one level, you can connect all the levels if they can drain comfortably into each other. You can choose low spots or create depressions at appropriate places. Swales help in water retention. Choose plants that are native to your area to reduce the need for maintenance.

Rain garden is becoming a popular concept especially among home developers who include this as a part of their project to reduce maintenance costs and infrastructure required for draining the rain water. Water from the parking lots flows into the rain gardens which absorb most of the harmful contaminants. The bacteria in the soil convert the harmful nitrates into nitrogen gas. They are very useful if the community as a whole is committed to create such an area as it would lower the chances of flooding and also overloading the drains during very heavy rainfalls or storms.

Rain gardens can be maintained all through the year without investing too much in maintaining it.

Jason Ladock

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