Rain Gardens to the Rescue

 

Rain gardens can dramatically cut the amount of pollution in urban storm water, according to a study by U.S. researchers.

A research team from the University of Connecticut says a shallow depression in a garden containing bark mulch and shrubs can remove up to 99% of toxins from stormwater runoff containing fertilizers, oil and particulates. The findings appear in the journal Environmental Science and Technology. For the study, two rain gardens were planted and frequently monitored over a two-year period to see how effectively they absorbed a range of pollutants.

The EPA estimates built-up urban areas generate nine times the amount of runoff water than woodlands of a similar size. The researchers noted the importance of rain gardens to help absorb downpours and mitigate stormwater volumes that can overload drainage systems. Dr. Dietz hopes their findings will encourage town planners across the globe to consider using rain gardens.