Green Infrastructure

Vegetated filter strips are uniformly graded and densely vegetated sections of land, designed to treat runoff and remove pollutants through vegetative filtering and infiltration.

Routine maintenance should be performed on vegetated filter strips. During the first year that the bioretention area is built, maintenance may be required at a higher frequency to ensure proper functionality.

Upon establishment, grass and vegetation should be cut and trimmed routinely to maintain a grass height of 3-12 inches or 6-15 inches along a roadway.

After a large rainstorm, keep drainage paths, both to and from the area, clean so that water can be properly filtered. If the vegetated filter is not draining properly, check for clogging in the inlet and outlet structures.

Fertilizers should not be used during or after the establishment of vegetated filter strips. Pesticides should be used sparingly and only if necessary.

Here are some of the common problems to be aware of when maintaining a vegetated filter strip. They include, but are not limited to, the following:

• Sediment build-up
• Clogging in the pea gravel diaphragm or other flow spreader
• Establishing vegetation within the vegetated filter strip
• Ant mounds
• Erosion
• Concentrated flow

Vegetated Filter Strips Routine Maintenance Schedule
Schedule	Activity
As needed	Mow grass to a height to maintain a dense vegetative cover. It is recommended that the height of grass is 3-12 inches and 6-15 inches along a roadway. Remove any grass clippings Keep the practice clean and remove all trash, sediment, and debris. Reseed any eroded or bare spots. Water the practice during dry conditions of vegetation establishment
Annually	Inspect vegetated filter strip for signs of erosion, and repair the strip as needed. Inspect for invasive species and remove as needed. Inspect pea gravel diaphragm for clogging and remove built-up sediment. Inspect vegetation for rills and gullies. Seed or sod bare areas. Inspect to ensure that grass has established. If not, replace with an alternative species.