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Using vegetated filter strips as pretreatment practices to other best management practices is highly recommended. They also provide a convenient area for snow storage and treatment, and are particularly valuable due to their capacity for snowmelt infiltration. If used for snow storage, the area should be planted with salt-tolerant, non-woody plant species. Because of the simplicity of filter strip designs, physical changes to the practice are not needed for winter operation.
Using vegetated filter strips as pretreatment practices to other best management practices is highly recommended. They also provide a convenient area for snow storage and treatment, and are particularly valuable due to their capacity for snowmelt infiltration. If used for snow storage, the area should be planted with salt-tolerant, non-woody plant species. Because of the simplicity of filter strip designs, physical changes to the practice are not needed for winter operation.
==Planning==
===Available Space===
The flow path length across the vegetated filter strip should be at least 5 m to provide substantial water quality benefits <ref name="Barrett2004">Barrett, M., Lantin, A., Austrheim-Smith, S. 2004. Stormwater pollutant removal in roadside vegetated buffer strips. Transportation Research Record. No. 1890, pp. 129-140.</ref>.
===Topography===
Filter strips are best used to treat runoff from ground-level impervious surfaces that generate sheet flow (e.g., roads and parking areas). The recommended filter strip slope is between 1 - 5 %. Though steeper slopes increase the likelihood of erosion, incorporation of multiple level spreaders in series or terraces can counteract this.
===Soils===
Filter strips are a suitable practice on all soil types. If soils are highly compacted, or of such low fertility that vegetation cannot become established, they should be tilled to a depth of 300 mm and amended with compost to achieve an [[organic matter]] content of 8 to 15% by weight or 30 to 40% by volume.
===Flow Path Length Across Impermeable Surface===
A limiting design factor is that the maximum flow path length across the impermeable surface should be less than 25 metres. This is because runoff flowing as sheet flow over an impermeable surface tends to concentrate after 25 metres <ref>Claytor, R. and T. Schueler. 1996. Design of Stormwater Filtering Systems. Center for Watershed Protection. Ellicott City, MD.</ref>. Once runoff from an impervious surface becomes concentrated, a [[swale]] design should be used instead of a vegetated filter strip <ref name="Barrett2004"/>.
==Gallery==
==Gallery==