section_path: Green infrastructure/Bioretention and infiltration practices
section_name: Bioretention and infiltration practices
paragraph_text: Bioretention and infiltration practices
  
  There are a variety of types of bioretention and infiltration practices, including rain gardens and bioswales. A rain garden is planted in a small depression or natural slope and includes native shrubs and flowers. They temporarily hold and absorb rain water and are effective in removing up to 90% of nutrients and chemicals and up to 80% of sediments from the runoff. As a result, they soak 30% more water than conventional gardens. Bioswales are planted in paved areas like parking lots or sidewalks and are made to allow for overflow into the sewer system by trapping silt and other pollutants, which are normally left over from impermeable surfaces. Both rain gardens and bioswales mitigate flood impacts and prevent stormwater from polluting local waterways; increase the usable water supply by reducing the amount of water needed for outdoor irrigation; improve air quality by minimizing the amount of water going into treatment facilities, which also reduces energy usage and, as a result, reduces air pollution since less greenhouse gases are emitted.