During the instructional planning stages, the teacher may wish to read About the Watershed: Instructional Framework, especially parts IV. Elements of a Watershed, V. The Chesapeake Bay Watershed as an Ecological System, VI. Conservation, Restoration, and Stewardship of the Chesapeake Bay Watershed, and VII. Chesapeake Bay Watershed Issues and Trends: Alternatives and Consequences.
What is a rain garden?
To begin this project, the teacher may wish to introduce students to the concept of a rain garden, including its purposes, forms, potential locations, and importance.
A rain garden is designed to catch rainwater and slow, decrease, and improve the quality of storm water runoff. A rain garden can take many different forms and, for the most part, is limited only by the resources and time a group has to put into it. It can be large, complicated, and expensive or small and relatively simple. Chesapeake Bay Foundation's rain garden design, described here step-by-step, is inexpensive and easy enough for most students to complete with minimal help from adults. And while this rain garden project is specifically written with the schoolyard in mind, it would work just as well at a home, community center, religious center, or any other private property.
Scientists have found that nutrient and sediment pollution are the largest threats to water quality in the Chesapeake Bay watershed. Here is something students can do about it.
Why create a rain garden?
Virtually every school has a substantial amount of impervious surface (area that rainwater cannot soak into) that affects the quality of storm water runoff. When rain lands on an impervious surface, it cannot soak into the ground and eventually enters a storm drain or a nearby creek. This excess water, called runoff, causes the soil in its path to erode more rapidly than it would naturally. Gravity then causes this runoff to flow downhill and into the closest stream or other waterway, carrying with it the sediment, pesticides, fertilizers, and other pollutants it encounters along the way.
Rain gardens contain plants that intercept and slow down the storm water runoff and absorb or trap much of what it contains. Rain gardens also restore wildlife habitat by attracting creatures such as insects, butterflies, toads, and predators like hawks. Creating a rain garden also helps build environmental stewardship in students.