Bioswales - vegetated swales

Bioswales are engineered open, shallow channels with vegetation covering their slopes and bottom. They are a form of low-impact development that helps prevent stormwater pollution by slowing down and infiltrating runoff as well as filtering out sediment and excess nutrients. Bioswales can also help infiltrate groundwater and reduce flooding.

  • They consist of multiple layers including: native plants, engineered soil, gravel. Depending on site conditions, they may include outflow pipes to aid with additional drainage and/or check dams to help reduce erosion.

  • Native plants can enhance the aesthetic value of the land and serve as a wildlife habitat for birds, insects and small animals.

Typical Maintenance Activities Include:

  • Remove sediment and debris that impedes infiltration

  • Mitigating compaction

  • Reseeding

See full WDNR Technical Standard - Vegetated Swales
Bioswales Fact Sheet

Please visit the Milwaukee Metropolitan Sewerage District’s Fresh Coast Guardians website to learn more about green infrastructure.