Slide 89 of 119
Notes:
Bioretention areas are landscaping features adapted to treat on-site stormwater runoff. They are commonly located in parking lot islands or within small pockets in residential land uses. Surface runoff is directed into shallow, landscaped depressions. These depressions are designed to incorporate many of the pollutant removal mechanisms that operate in forested ecosystems. During storms, runoff ponds above the mulch and soil in the system. Runoff from larger storms is generally diverted past the facility to the storm drain system. The remaining runoff filters through the mulch and prepared soil mix. Typically, the filtered runoff is collected in a perforated underdrain and returned to the storm drain system.
Bioretention systems are generally applied to small sites, and in a highly urbanized setting. Bioretention can be applied in many climatological and geologic situations, with some minor design modifications.