Rain Gardens

Every time it rains, stormwater flows down roofs, driveways, and other impervious surfaces, sometimes flooding basements or collecting in low spots. Other runoff continues on toward the street, picking up soil, pesticides, and other contaminants before it enters storm drains that transport it to streams and lakes, often without treatment.

Think of a rain garden as a sponge—an environmentally-friendly sponge—that is designed to soak up much of this runoff before it can do damage.

A rain garden starts with a bowl-shaped bed of loose soil. The garden is planted with deep-rooted trees, bushes, flowers, and other plants that help absorb the stormwater, which filters through layers of soil before entering the groundwater system.

With just a little effort, a rain garden can be a beautiful, low-maintenance addition to your lawn. Its contribution to our region’s water quality may seem small. But if we all do our part, the total impact can be environment-changing.

Rain gardens reduce the potential for basement flooding. A rain garden gives runoff a beneficial, safe place to go, helping to keep it away from your home’s foundation.

Rain gardens reduce garden maintenance. A rain garden essentially “waters itself,” requiring little or no additional irrigation. In fact, rain gardens are more likely than other gardens to survive droughts. Periodic weeding, mulching, and pruning are all the maintenance they need. Because you don’t need to fertilize or spray them, they make your yard a healthier place for your children and pets as well.

Rain gardens enhance curb appeal. Because are more tolerant of the local climate, soil, and water conditions, native plants are recommended for rain gardens. These plants also provide interesting planting opportunities, and are an attractive and creative alternative to traditional lawn landscapes.

Rain gardens increase garden enjoyment. Rain gardens are not only pleasing to look it, they are an ideal habitat for birds, butterflies, and other wildlife.

Rain gardens reduce mosquitoes. In a properly designed rain garden, water will soak into the ground within a day or two, long before mosquitoes have the opportunity to breed. They can also can be designed to attract the kinds of insects that eliminate pest insects.

Rain gardens help improve water quality. The plantings in rain gardens help to filter contaminants from run-off, improving the quality of the water that recharges our groundwater. Your rain garden makes you part of a solution to stormwater pollution.

Rain gardens reduce the burden on public sewer systems. Rain gardens collect and use stormwater that would otherwise drain into the sewer system. By diverting this water, rain gardens decrease the flow to our wastewater treatment plants (WWTPs) during storms, when flow typically peaks.

Rain gardens reduce sewer overflows and flooding. If adopted on a community or neighborhood scale, rain gardens can reduce combined sewer overflows (CSOs) and localized flooding.

Rain gardens protect rivers and streams. Polluted stormwater that enters rivers and creeks untreated can hurt both water quality and the wildlife that inhabit them. Excessive runoff can also erode banks and increase downstream flooding as well. Rain gardens can help minimize both.

1. Choose your garden’s location. The first step in planning a rain garden is to walk your property while it is raining, and watch how runoff moves on the site. Rain gardens are best located:
   • in low spots where runoff collects, but then soaks into the ground within 24 hours
   • in places with partial to full sun
   • at least 10 feet away from a home to prevent leaks into your basement
   • away from steep slopes that can become unstable when saturated
   • away from septic systems or pipes
2. Check for underground pipes. Before breaking ground, call to arrange to have utility workers mark the location of underground lines.
3. Select your plants. Choose native plants that bloom at different times of the season and have a variety of heights, shapes, and textures.
4. Dig. A rain garden is usually one to two feet deep with a flat bottom and angled sides. Most are between 100 and 300 square feet in size.
5. Plant, water, and tend. You will need to water your rain garden, especially when it’s first planted and during dry weather. Rain gardens also need to be regularly weeded and mulched.
6. Share. Cuttings from the plants in your garden can be replanted in your neighbors’ and friends’ gardens.