What is bioretention?
Bioretention is a technique using natural methods to remove harmful pollutants in stormwater runoff through a variety of physical, biological, and chemical treatment processes. Pollutants such as particles of dirt, oils, chemicals, and harmful bacteria are removed during the filtering process as water moves through vegetation, mulch, soil, sand, and gravel. Rain gardens are a common small scale stormwater management technique that use bioretention.
Benefits of bioretention
· Filters pollutants from stormwater runoff.
· Reduces the volume and speed of stormwater runoff to protect against flooding and prevent erosion in streams and rivers.
· Recharges groundwater supply by infiltrating stormwater when possible.
· Utilizes plants that absorb pollutants and create wildlife habitat.
What does bioretention do?
Bioretention captures, holds, and filters stormwater runoff from streets, sidewalks, and other paved areas that do not allow water to soak into the ground. It also treats runoff from managed landscapes with compacted soils contaminated with pesticides and fertilizers. Bioretention prevents runoff carrying pollutants from discharging directly into storm drains that lead to a stream or waterway.