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− | [[File:Vegetated_filter_strip_1.jpg|thumb|Hey Dean, What's the caption for this photo?]] | + | [[File:Vegetated_filter_strip_1.jpg|thumb|Grass filter strip draining to vegetated swale. Source: Trinkhaus Engineering]] |
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| ===Soil Amendments=== | | ===Soil Amendments=== |
− | If native soils on the filter strip site 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 - 15 %. | + | If native soils on the filter strip site 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 5 - 15 %. |
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| ==Landscaping== | | ==Landscaping== |
− | Filter strip vegetation can consist of [[Turf|turf grasses]], meadow [[Graminoids: List|grasses]], [[Perennials: List|wildflowers]], shrubs, and [[trees]]. Trees and shrubs with deep rooting capabilities are recommended for planting to maximize soil infiltration capacity <ref>Philadelphia Water Department (PWD). 2007. Philadelphia Stormwater Management Guidance Manual. Philadelphia, PA.</ref>. | + | The context of filter strips is often natural, informal and somewhat informal. Filter strip vegetation can consist of [[Turf|turf grasses]], meadow [[Graminoids: List|grasses]], [[Perennials: List|wildflowers]], shrubs, and [[trees]]. Trees and shrubs with deep rooting capabilities are recommended for planting to maximize soil infiltration capacity <ref>Philadelphia Water Department (PWD). 2007. Philadelphia Stormwater Management Guidance Manual. Philadelphia, PA.</ref>. |
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| *Filter strips used for snow storage and treatment should be planted with non-woody vegetation. Designers should choose vegetation that stabilizes the soil and is salt tolerant where the filter strip will be used for snow storage or to treat road runoff. | | *Filter strips used for snow storage and treatment should be planted with non-woody vegetation. Designers should choose vegetation that stabilizes the soil and is salt tolerant where the filter strip will be used for snow storage or to treat road runoff. |
− | *Vegetation at the toe of the slope (where ponding may occur) should be able to withstand both wet and dry soil conditions. | + | *Vegetation at the toe of the slope (where ponding may occur) should be able to withstand both wet and dry soil conditions. |
| + | *Whatever the type of vegetation used, it must be densely planted to slow runoff, collect sediment, and allow for infiltration. |
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| Although filter strips are often grassed, alternatives include forested filter strips or multi-zone filter strips, which feature several vegetation zones providing a gradual transition from turf to meadow to shrub and forest. The multi-zone filter strip design can be effective as a buffer zone to an existing natural heritage feature. | | Although filter strips are often grassed, alternatives include forested filter strips or multi-zone filter strips, which feature several vegetation zones providing a gradual transition from turf to meadow to shrub and forest. The multi-zone filter strip design can be effective as a buffer zone to an existing natural heritage feature. |
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− | Maintaining sheet flow into the filter strip through the use of a level spreading device (e.g., pea gravel diaphragm) is essential.
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| {{:turf}} | | {{:turf}} |
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| {{:Filter strips: Performance}} | | {{:Filter strips: Performance}} |
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− | [[Category:GI]]
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| [[Category: Pretreatment]] | | [[Category: Pretreatment]] |