The Parking Structure I was awarded "Project of the Year" by the American Public Works Association in 2010. Its sustainability features include energy-efficient lighting, an electric automobile charging station, and a bioswale. The bioswale is a natural filtration system for dirty water. It is built on a gentle slope that allows rain water to seep into the carefully constructed layers of soil and gravel. Specially selected species of plants are grown that resist being torn away by rushing water. The plant roots (and other very important organisms we forget about because they are too small to see, like soil bacteria and fungi...) clean the water of toxins that get washed into it. Some of the things that are in the rushing rain water coming off parking lots and roads are brake dust from cars, engine oil, pesticides, etc. The bioswale removes harmful chemicals and silt (suspended particles of very fine dirt) from the water before it's guided into the storm water drainage system that goes into lakes, streams and ponds, ending up in the ocean. In addition to all those marvelous accomplishments, the bioswale provides erosion control and shade in a pleasant park-like setting.

What are some of the reasons to construct a bioswale? Reread the paragraph above to review the amazing things a bioswale does!