Bioretention Systems & Rain Gardens

Bioretention Systems and Rain Gardens use plants and soil to capture, infiltrate, and treat stormwater runoff. They are flexible in design and are both popular green infrastructure practices used to meet infiltration requirements in Washtenaw County. While they have some differences and can vary in size and scope, many of their materials, needs, and design elements are similar.

Stormwater runoff can be directed into these systems where pollutants are removed as water is infiltrated into the ground. Native vegetation helps support infiltration while plants also soak up water. Bioretention systems and rain gardens can create vibrant and attractive natural spaces for residential and commercial sites.

Bioretention & Rain Garden Factsheet - SEMCOG


Maintenance is critical for bioretention systems and rain gardens 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 trash or debris, cleaning out sediment, and repairing erosion
  • Keeping plants healthy, removing weeds, and replacing plants that don’t survive
  • Watering plants during establishment periods and in extended droughts