Bioswales (Vegetated Swales)

Bioswales are shallow channels with vegetation that are designed to slow, filter, infiltrate, and convey runoff. They are densely planted with a variety of locally adapted grasses, shrubs, and/or trees and do not have underdrains.  Check dams can be installed to improve sediment capture and increase the time of concentration. 

Deep-rooted and native wetland and upland plants help stormwater infiltrate while providing vibrant natural spaces for residential and commercial sites.  While maintenance is critical for bioswales to function and look nice, costs and time can be reduced compared to conventional lawn care.

Bioswales Fact Sheet - SEMCOG


Maintenance is critical for bioswales to function and look nice over the years. Planning for ongoing maintenance will support plant communities as they grow and establish. Routine tasks include:

  • Removing weeds through mowing and prescribed burns and replacing plants that don’t survive
  • Watering plants during establishment periods and in extended droughts
  • Inspection of slopes and check dams, erosion repair, and sediment removal