When rain falls or snow melts we see it collecting into streams along roads to drain into gutters. Few people know where the water goes, let alone the environmental impacts. Where water goes is crucial to the health of the land and people of any community. Modern storm water management is costly, both in the engineering required and the environmental degradation it causes. Rain Gardens are an increasingly popular alternative to modern storm water management that have low environmental impact, are far less expensive, and can be done in your own backyard.
Stormwater runoff is water from precipitation that moves across impervious surfaces, such as roofs and pavements, and across land, usually into the nearest stream, creek, lake, river, or ocean rather than infiltrating into the ground. Urban development has led to an increase in stormwater runoff and a dramatic decrease in the vegetation that is vital in infiltrating water.
Typically, stormwater runoff is untreated and carries pollutants from the land and pervious surfaces and contaminates water systems. The pollutants in this runoff include particles from roofs, car oils and fluids, lawn treatments, chemicals used in gardens and on landscape plants, toxins in household cleaning products, and trash. This process is problematic because it threatens water quality. Poor water quality jeopardizes plant, animal and insect habitat and life. Drinking water supplies and human life are also endangered by poor water quality.
Erosion is another consequence of an increase in impervious surfaces and a lack of deep-rooted native vegetation. Stormwater runoff washes soil, trees and rock into water systems and downstream. This leads to property loss, changes in stream courses and damming. Conventional stormwater management techniques that consist predominantly of piping water directly into the closest waterways, overload these systems and cause flooding. The effects of a stormwater drainage system add tremendously to the already high cost of development.
Rain gardens are shallow landscaped depressions that include specialized, native plantings and soil with high infiltration rates. These small patches of vegetation are designed to capture and infiltrate water runoff from surrounding areas. Rain gardens are a popular, low maintenance form of stormwater management and beautification. They serve as an element in the landscape that has both aesthetic and ecological functions. Rain Gardens are used to control runoff volume and timing and can remove pollutants through the physical, chemical and biological processes that occur in plants, soil, and mulch. Rain gardens help raise awareness about ecological issues, increase infiltration, decrease surface runoff from roofs, roads, and paved areas, reduce the risk of flash flooding and provide a home for wildlife.
Rain gardens are best placed in typical drainage routes. They are ideal near downspouts, near street drains, and on slopes leading to water features. A rain garden is best located away from paths and heavy traffic areas to prevent compaction and trampling.
Local to Global
Iowa State University is a prestigious academic facility equipped with honorary programs in landscape architecture, agriculture, environmental sciences, studies and engineering. Iowa State’s campus is among three central campuses on the national landscape architects’ centennial list of great sites and was rated among America’s 25 most beautiful campuses in the book “The Campus as a Work of Art”. However, the way in which Iowa State University is currently dealing with stormwater management is problematic. Iowa State University uses conventional methods and runs stormwater directly into College Creek, which has become lifeless because of the prevalence of toxins. This is only a microcosm of a problem that exists all over the world. College Creek drains into several rivers until it reaches the Mississippi, the third longest river in the world. From the accumulation of all the poisoned creeks and rivers that flow into it, the Mississippi has been made lifeless as well, and Iowa is the largest source of chemical runoff from modern row crop farming. This problem can only be solved locally. Do your part and add a rain garden to your property.
This information was taken from a Landscape Architecture Senior Project by Clare Kerofsky and Angie Mitzel and additional research.