Bioretention Cells and Bioswales

What is it?

• Gardens (usually containing plants with long root systems) meant to retain, trap, and absorb rain water

Where can they be used?

• Bioretention cells are often used around homes to provide an aesthetically pleasing environment
• Bioswales are used in long strips, typically along roadways and parking lots
• Residential areas
• Commercial areas

How do they work?

• Water is filtered by soil and vegetation
• Allows rain water to infiltrate the soil at a slower rate than normal, which reduces peak strain on waste water systems
• Roots create root channels which allow water to infiltrate up to a foot into the soil, even in tough soils and clay



view from back


• Reduces runoff
• Improves water quality of runoff
• Provides pleasant garden space, or roadside greenery


• Must be maintained to be kept effective, without the use of fertilizers or chemicals

Other Information

• A single large tree can absorb up to 90,000L of rain water a year

What should you plant?

The best option for vegetation in your bioretention cell is a diverse mix of native species. Trees are especially effective at trapping and filtering water.

Native Species