Rain gardens can reduce the amount of pollution getting to natural bodies of water because they act like filters.
Because they also act as filters, rain gardens can even reduce the amount of pollution getting to natural bodies of water. Rain gardens are receiving greater attention as an effective approach to reduce storm water runoff. They cost a fraction of the installation and maintenance cost of permanent “best management practices”—such as retention ponds. (2015) Blog post on the Soil Science Society of America.