What is a rain garden?

Rain garden full of water after a rain

A rain garden is a shallow, vegetated landscaping feature that captures rainwater and puts it to work. As the rain garden bed is slightly below the level of the yard, the garden acts as a shallow dish that holds the water for a short time so that it can soak into the garden soil. Well-designed rain gardens absorb 30% more water than turf lawns and will drain completely within a day after an average storm.


What are the benefits of a rain garden?

Rain gardens have many benefits. First, it is an attractive and unique addition to any yard. Both you and your neighbors will enjoy its beauty for years to come.

In addition, rain gardens provide environmental benefits by improving water quality and promoting water conservation. Water that runs off hard surfaces, like your roof, and from your yard during rain events flows down the street collecting contaminants such as automobile fluids, yard fertilizers, and pet waste. This adds pollution to the environment because storm drain water is not treated before it enters your local rivers. For example, yard waste and fertilizers add excessive amounts of nutrients to rivers. Nutrients cause algae to grow, which depletes oxygen in the water that fish and other aquatic life depend on. By collecting runoff before it reaches the street, rain gardens reduce the amount of polluted water flowing into storm drains. Research has shown that the intensive installation of rain gardens in neighborhoods can greatly reduce storm water runoff and street flooding.

The water retained in the garden soaks down into the soil, providing water for the garden plants as well as for the underlying groundwater. This minimizes the need for watering and helps conserve municipal water supplies.

Finally, the native plants used in rain gardens provide habitat for birds, butterflies and other beneficial insects. Native plants also require less maintenance, particularly less watering, over time because they are adapted to the local soil and climate conditions and have deep root systems. And if you plant perennials, you will not have to replant every year.

What are the steps for creating a rain garden?

  1. Decide where you want the rain garden located and where it would be most effective in collecting the runoff from your property (i.e., close to a downspout).
  2. Design the garden. Determine the garden size and depth that will maximize the amount of runoff the garden receives. Garden shape is largely a matter of preference or available space.
  3. Select your plants. Choose moisture-loving species for the garden bottom and drought-tolerant species for the sides and berm. Selecting plants that are diverse in color, height, texture, and blooming time results not only in a more interesting display, but one that attracts a greater variety of birds and insects.
  4. Plant the garden. Planting time depends mostly on the size of your garden. For most gardens, a few people working together will be able to complete the project in a day. Ask your friends and neighbors for help; this is a great opportunity to spread the word about the benefits of rain gardens.

How much will it cost?

Downspout extensions drain into a rain garden
with hardscape to soften the impact of
incoming water

The cost of installing a rain garden depends on several factors such as garden size, your yard’s soil type, and the plants selected. You can reduce the cost of plants by selecting younger plants, getting plants from friends, or raising your own from seed. You can also plant in phases; completing one section of the garden this year, and then completing the planting in the following year.

Where can I get more information?

If you would like more information about rain gardens or would like PRN to give your group a presentation on why rain gardens are beneficial and the basic steps of design and installation, please contact us at (217) 344-2371 or info@prairierivers.org.

Download our Rain Garden Brochure.

Visit the Wisconsin Department of Natural Resources website, where you can download their rain garden manual. The manual has detailed information on how to design and install a rain garden.

Look at our Table of Native Plants Suitable for Illinois Rain Gardens.

View pictures of Illinois native plants.

See what plants might work for your rain garden using the Blue Thumb Plant Selector Tool.

Find nurseries that sell native plants.

Rain gardens that have been installed with the help of Prairie Rivers Network

Sand and compost were tilled into this rain garden to increase water permeability (Champaign)

Digging the rain garden within the stakes that outline the desired shape, at a new Habitat for Humanity home (Champaign)

Students plant a rain garden next to Presby Hall, containing the roof runoff and air conditioning condensation so that the courtyard grass is less boggy (Champaign)

This rain garden captures runoff from Washington Street (Champaign)

The rain garden at Meadowbrook Community Church captures runoff from the parking lot (Champaign)

Residential rain garden that captures water from both a downspout and sump pump (Champaign)