Bioretention cells capture and infiltration of stormwater runoff from impervious surfaces to reduce water pollution and stabilize stream flows. Bioretention cells have an engineered and constructed sub-grade to ensure adequate percolation and infiltration of captured runoff.
Bioretention cells can be used in most settings including parking lots and residential areas where soils don’t adequately percolate. They use plants that can tolerate a wide range of moisture conditions. Native plants are encouraged because they are deep rooted, they help maintain soil quality and good percolation.
A limiting factor for placement of a bioretention cell may be the lack of an outlet for the sub-drain. An outlet is necessary to ensure proper drainage. The sub-drain often outlets into the storm sewer or can discharge down gradient of the bioretention cell.