Ever since humans began tending to small patches of cultivated ground near their homes, the terms “rain” and “garden” have gone together.
These days, these two words have merged to form the name of an innovative and eco-friendly landscaping device that’s gaining in popularity, particularly in urban areas. An increasing number of residential and commercial property owners are discovering how rain gardens can decrease erosion, improve water quality, create wildlife habitat, and provide aesthetic benefits.
In essence, a rain garden is a shallow depression that captures rain water and holds it until it is absorbed into the ground, evaporates or is taken up by plants. They function best – and with greatest benefits for humans – in areas that have a lot run-off from rain and this is why their popularity is growing in urban areas. From a wildlife habitat and water quality standpoint, rain gardens are beginning to provide solutions to urban problems that have existed for a long time.
As urban areas are developed, much of the landscape becomes topped with impervious surfaces in the form of asphalt parking lots, streets, sidewalks and buildings. Even un-paved areas often lose water absorption capabilities as soil becomes more compacted and land-cover plants change from diverse native vegetation to mowed and manicured lawns. These factors decrease the amount of water that soaks into the landscape after a rain and increases the quantity of water that surges across the terrain and into local streams. This increased water flow (both in terms of volume and velocity) leads to more erosion, more flooding and more pollutants being washed into streams and reservoirs.
Rain gardens provide a solution to these problems by helping to slow the flow. Since a rain garden is a shallow depression, it slows the stormwater as it travels downhill, giving it more time to infiltrate and less opportunity to gain momentum and erosive power. But you’re not merely building a catch-basin that’s going to turn into a pond every time it rains. Far from it. With the appropriate soil, proper plants and good design; water is absorbed quickly – usually within a few hours. A well-functioning rain garden is a small bio-retention cell that “cleans” stormwater and reduces its volume (through rapid absorption) once it enters the
garden.
Rain gardens don’t just help to keep soil and pollutants from washing downstream. The plants in the gardens provide important habitat for pollinating insects, birds and other wildlife. And, in case you think your rain garden will provide a new breeding area for neighborhood mosquitoes – think again. A rain garden doesn’t retain water long enough to make it a viable area for mosquito development. (Depending on temperature, it takes 24-48 hours for mosquito eggs to hatch. After the eggs hatch, the larva must live in water for several days.)
And, of course, rain gardens also can supply viewing pleasure for humans. Some of the same native wildflower blooms and plants that attract pollinators and birds can also add visual appeal of the land around your home or your business.
People can learn more about rain gardens by visiting the demonstration rain garden on the west side of the Missouri Department of Conservation building at this year’s Ozark Empire Fair. People can learn also see fish, reptiles and pick up a variety of conservation-related literature inside Department of Conservation building, which is open 4-9 p.m. on the opening day of the Fair on Thursday (July 27) and 11 a.m.-9 p.m. each day for the remainder of the fair. (The Ozark Empire Fair runs through Saturday, Aug. 5).
Information about conservation-friendly rain gardens can also be found at mdc.mo.gov.
Francis Skalicky is the media specialist for the Missouri Department of Conservation’s Southwest Region. For more information about conservation issues, call 417-895-6880.
