Changes

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.

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===

===Flow Path Length Across Impermeable Surface===

A limiting design factor is that the maximum flow path length across the impermeable surface must be < 25 m, as flow tends to concentrate ≥ 25 m over an impermeable surface.<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 [[swales|swale]] design should be used instead of a vegetated filter strip <ref name="Barrett2004"/>.

A limiting design factor is that the maximum flow path length across the impermeable surface must be < 25 m, as flow tends to concentrate ≥ 25 m over an impermeable surface.<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 [[swales|swale]] design should be used instead of a vegetated filter strip <ref name="Barrett2004"/>.

==Design==

==Design==