Filter Strips

What is it?

  • A gently sloping piece of vegetated land

Where can they be used?

  • Between an impermeable surface and a waterway such as a stream or lake

What sectors commonly use them?

  • Residential
  • Industrial
  • High density residential
  • Retrofit
  • Agriculture

How do they work?

  • Accept overland flow from runoff
  • As water runs down the hill, it is treated by vegetative filtering
  • As water is travelling towards the stream, it infiltrates the ground where appropriate
  • Sediment, nutrients, pathogens, and pesticides can be filtered out of the runoff and trapped in the soil and plants


  • Can treat water originating from large impermeable areas
  • Encourages evaporation and infiltration prior to putting runoff back into the watershed
  • Easy to build/low construction cost
  • Provides effective pre-treatment
  • Easily integrated into normal landscaping design and can be aesthetically pleasing if local grass and flower species are added
  • Effective at removing solid pollutants through filtration and sedimentation
  • Can provide habitats for small birds and animals
  • Can prevent bank erosion


  • Site must not be too steep
  • Site must be located next to a water source
  • Not suitable for use near locations where groundwater contamination is a concern
  • To maintain the effectiveness of a filter strip, the vegetation must be kept healthy without the use of fertilizers or chemicals