PlacementVegetated box filters are used throughout the United States, and are especially useful
in settings where space is at a premium. They are either open or closed bottomed chambers where infiltration is not possible or not wanted, such as clay
soils, sites with high groundwater, or areas with highly contaminated runoff.
Vegetated box filters are often installed along urban sidewalks, but they are highly adaptable and can be used in most development scenarios. In urban areas, vegetated filters can be used in the design of an integrated street landscape—a choice that transforms isolated street trees into stormwater filtration devices. They also can be used in designs that seek to convert entire non-functional streetscapes into large stormwater or combined sewer flow filtration systems.
Implementation
These systems are a relatively recent innovation that is growing in usage, especially
in urban areas. The cost to install a tree box filter to replace a catchbasin is $2,500, exclusive of maintenance. Observations, thus far, reinforce stormwater
manual assessments that maintenance requirements for these systems are generally minimal. In general, vegetated box filters are sized and spaced much like catch basin inlets,
and design variations for these systems are abundant.
Download our FACT SHEET (PDF) for more details.
