Low Impact Development Manual for Michigan - OSEH - University ...

BMP Fact Sheet
Vegetated Filter Strip
A vegetated filter strip is a permanent, maintained strip of vegetation
designed to slow runoff velocities and filter out sediment and other pollutants
from urban stormwater. Filter strips require the presence of sheet flow
across the strip, which can be achieved through the use of level spreaders.
Frequently, filter strips are designed where runoff is directed from a parking
lot into a stone trench, a grass strip, and a longer naturally vegetative strip.
Vegetated filter strip along roadway
Source: Wayne County Department of Environment
Applications Stormwater Quantity Functions
Residential Yes Volume Low
Commercial Yes
Groundwater
Recharge
Variations
• Turf grasses
• Prairie grasses, shrubs, and
groundcover vegetation, including
trees
• Indigenous woods and dense
vegetation
Key Design
Features
• Use with level spreaders to
promote sheet flow across
strips
• Longitudinal slope from 1-6
percent
• Maintain dense vegetation
• See Appendix for recommended
filter strip native vegetation
Site Factors
• Water table to bedrock depth –
N/A
• Soils – N/A for permeability
• Slope – 2-5 percent preferred
(1-10 percent if soils/vegetation
allow)
• Potential hotspots – Yes with
special design considerations
• Max. drainage area – 100
feet impervious or 150 feet
pervious upgradient
Benefits
• Low cost
• Good water quality performance
• Aesthetic and habitat benefits
Limitations
• Generally should be coupled
with other BMPs for comprehensive
stormwater management
LID Manual for Michigan – Chapter 7 Page 289
Low
Ultra Urban Limited* Peak Rate Low
Industrial Limited* Stormwater Quality Functions
Retrofit Yes TSS Med/High
Highway/Road Yes TP Med/High
Recreational Yes
NO3
Med/High
Temperature Med/High
Additional Considerations
Cost Low
Maintenance
Low/Medium
Varies dependent on type of vegetation
Winter Performance High
* According to site characteristics