Rain gardens are stormwater bioretention systems, consisting of a shallow depression which employs native prairie vegetation. The deep root systems of the plants assist in increasing the infiltration of stormwater into the ground. Turf and cement, common ground covers in urban areas, are highly impermeable and ineffective for stormwater infiltration and can cause flooding. Traditional stormwater drainage systems commonly reroute stormwater runoff directly to surface water sources, such as rivers and lakes. This can be harmful if the stormwater is carrying pollutants which can contaminate these water sources. Rain gardens are an excellent solution to this, serving not only as a flood mitigation system, but also as a means of filtering pollutants out of stormwater through the soil, and regenerating local groundwater aquifers.

In the coming years, climate models point towards an increase in the frequency and intensity of precipitation in the Upper Midwest, making it more necessary for improved drainage systems, to prevent future flooding events and the consequences that accompany them. The purpose of this study is to investigate the effectiveness of rain gardens as bioretention systems and design a rain garden for stormwater management on Beloit College’s campus. This will involve analyzing future climate patterns for the Upper Midwest, finding the infiltration rates of different spaces and soils on the College campus, and determining what native vegetation is most effective for promoting infiltration.