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| The exceptions are the depth (''d'') and Permeable area (''P''), as only one of these is required to find the other. | | The exceptions are the depth (''d'') and Permeable area (''P''), as only one of these is required to find the other. |
| Note that some of these parameters are limited: | | Note that some of these parameters are limited: |
− | *The ''maximum'' total depth will be limited by construction practices i.e. not usually > 2 m.
| + | #The ''maximum'' total depth will be limited by construction practices i.e. not usually > 2 m. |
− | *The ''maximum'' total depth may be limited by the [[Infiltration| conditions underground]] e.g. the groundwater or underlying geology/infrastructure.
| + | #The ''maximum'' total depth may be limited by the [[Infiltration| conditions underground]] e.g. the groundwater or underlying geology/infrastructure. |
− | *The minimum total depth may be limited by the need to support vegetation i.e. not < 0.6 m.
| + | #The minimum total depth may be limited by the need to support vegetation i.e. not < 0.6 m. |
− | | + | #The area P for a [[green roofs]], [[absorbent landscapes]] and [[permeable paving]] may be very similar or equal to the catchment area, so that the I/P ratio is close to 1. |
− | | + | #[[Infiltration trenches]], [[Infiltration chambers| chambers]] and [[bioretention cells]] have a maximum recommended I/P ratio of 20. |
− | *The area P for a [[green roofs]], [[absorbent landscapes]] and [[permeable paving]] may be very similar or equal to the catchment area, so that the I/P ratio is close to 1.
| |
− | *[[Infiltration trenches]], [[Infiltration chambers| chambers]] and [[bioretention cells]] have a maximum recommended I/P ratio of 20.
| |
| | | |
| {|class="wikitable" | | {|class="wikitable" |
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| <math>P=\frac{IiD}{nd+qD}</math> | | <math>P=\frac{IiD}{nd+qD}</math> |
| | | |
| + | This spreadsheet has been set up to perform either of the above calculations. |
| <strong>[[Media:Infiltration Sizing.xlsx|Download .xlsx calculation tool]]</strong> | | <strong>[[Media:Infiltration Sizing.xlsx|Download .xlsx calculation tool]]</strong> |
| | | |
| [[category: modeling]] | | [[category: modeling]] |
| [[category: infiltration]] | | [[category: infiltration]] |