By Eden Gallanter
California’s got issues–with water. In the Bay Area, we experience long periods of relatively dry weather followed by heavy rains, and often have hard, clay soils to deal with. When storm water flows over pavement and rooftops, it washes away pollutants from vehicle oil and exhaust, pet waste, pesticides, and trash, all of which get into our water system and into natural bodies of water like the San Francisco Bay. Because we live in a dry climate inclined toward drought, conserving and protecting fresh water is in our best interest.
Rain gardens are an elegant, practical solution to many of our water-related concerns in the San Francisco Bay Area. They can collect and purify thousands of gallons of rainwater, which not only keeps pollutants and excess water away from the storm system, but also benefits surrounding plants. Rain gardens break up hard, compacted earth by pushing their roots deeply into the soil, allowing both water and nutrients in, to be held for later use by surrounding plants and microorganisms. Because of their ability to increase groundwater supply, rain gardens planted in a public space can benefit the backyards of all those people living nearby.
Rain gardens are defined by the following two characteristics: they are planted in a shallow ditch, and contain native plants and grasses with deep roots. Their purpose is to absorb stormwater runoff. For that reason, they are located next to parking lots and other paved areas, downspouts, and sump pumps. Rain gardens intercept rainwater before it floods city streets and rushed into storm sewers. They lighten the burden of a heavy rainstorm on municipal infrastructure, which saves money and prevents storm system breakdowns.
Rain gardens offer many fringe benefits aside from their usefulness in managing storm water. Effective local rain gardens contain California native plants that attract birds and insects, such as butterflies and lacewings, which are good for your garden. Rain gardens also offer a slice of green in the gray cityscape, keeping the city cooler in hot weather. Rain gardens can also be used as an educational tool for schools and adult programs. These lush patches provide a space for a community to work together on something that is good for people and the environment. Finally, rain gardens are beautiful. Budding green plants, grasses, and flowers can change the entire character of a sidewalk, parking lot, or the dank corner of your yard where the gutter drains from your roof.