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| *Regular fresh applications of wood mulch can also promote denitrification, reducing nitrates in impacted surface waters. | | *Regular fresh applications of wood mulch can also promote denitrification, reducing nitrates in impacted surface waters. |
| *Double-shredded hardwood or softwood mulch is recommended for LID facilities. Its fibrous texture knits together somewhat; providing limited erosion control. | | *Double-shredded hardwood or softwood mulch is recommended for LID facilities. Its fibrous texture knits together somewhat; providing limited erosion control. |
− | *Mulch can also help to maintain the organic matter content of filter media, which provides cation exchange capacity for pollutant removal. | + | *Mulch can also help to maintain the organic matter content of underlying filter media, which provides cation exchange capacity for pollutant removal. |
| ===Contraindication=== | | ===Contraindication=== |
− | *In areas with particularly high flow (e.g. around [[inlets]] and [[forebays]]) coarse decorative aggregate or [[stone]] is recommended instead, as these will not float. All organic mulches have the potential to float and migrate in surface flow, particularly after a previously dry period. <ref> Simcock, R and Dando, J. 2013. Mulch specification for stormwater bioretention devices. Prepared by Landcare Research New Zealand Ltd for Auckland Council. Auckland Council technical report, TR2013/056 </ref> | + | *In areas with particularly high flow (e.g. around [[inlets]] and [[forebays]]) coarse decorative aggregate or [[stone]] is recommended to cover the filter bed, to better dissipate energy. All organic mulches have the potential to float and migrate in surface flow, particularly after a previously dry period. <ref> Simcock, R and Dando, J. 2013. Mulch specification for stormwater bioretention devices. Prepared by Landcare Research New Zealand Ltd for Auckland Council. Auckland Council technical report, TR2013/056 </ref> |
− | *This advice also holds for [[stormwater planters]], which often experience concentrated flow from a [[downspout disconnection]] or similar. | + | *This advice also holds for [[stormwater planters]], which often experience concentrated flow from a [[downspout disconnection| roof downspout or drain]]. |
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| [[Category:Materials]] | | [[Category:Materials]] |
| [[Category:Green infrastructure]] | | [[Category:Green infrastructure]] |