A rain garden is a shallow depression planted with a variety of deep-rooted flowers, shrubs and grasses that are native to the region. A rain garden collects storm water from a roof, driveway, or street and allows it to soak into the ground, helping to filter out impurities.
When it rains, solid surfaces such as parking lots, streets, and sidewalks do not allow the water to soak into the ground. This contributes to the pollution of the water. Rain gardens collect the water and slowly filter it back into the soil, naturally removing pollutants from the runoff. When planted with the right types of plants, rain gardens also provide habitats for birds, butterflies and other wildlife.
Urban rain gardens at the Kalamazoo Valley Community College’s Anna Whitten Hall and Kalamazoo Valley Museum help manage the negative effects of stormwater runoff and pollution. The garden beds in both locations utilize “bioretention media.” This refers to an intentional way of layering soil, mulches, turf and grasses to maximize the filtration of heavy metals and other pollutants from the stormwater.
Permeable paver systems used near the garden beds at the two sites improve the negative impact of stormwater runoff. Water filters through the pavers into internal storage chambers so there is less chance of flooding. The pavers provide filtration that eliminates some pollutants.