Changes

|''q''||mm/hr||Infiltration coefficient of the underlying native soil, calculated from measured [[Infiltration: Testing| infiltration rate]] and applied [[Infiltration|safety factor]]

|''q''||mm/hr||Infiltration coefficient of the underlying native soil, calculated from measured [[Infiltration: Testing| infiltration rate]] and applied [[Infiltration|safety factor]]

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|''n''||-||Porosity, as measured (or default to 0.35 for all aggregates).<br> *Note: For systems that have significant storage in clear open chambers, an effective porosity value (''n<nowiki>'</nowiki>'') may be estimated for the whole installation and used in the calculations below. Effective porosity will vary according to the geometry of the storage chambers, so advice should be sought from product manufacturers. Permit applications should include the basis for ''n<nowiki>'</nowiki>'' estimates.

|''n''||-||Porosity of the aggregate or other fill material (e.g. 0.4 for clear stone).<br> *Note: For systems that have significant storage in clear open chambers or other void producing structures, an effective porosity value (''n<nowiki>'</nowiki>'') may be estimated for the whole installation and used in the calculations below. Effective porosity will vary according to the geometry of the storage chambers, so advice should be sought from product manufacturers. Permit applications should include the basis for ''n<nowiki>'</nowiki>'' estimates.

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|''I''||m²||Impermeable area i.e. catchment

|''I''||m²||Impermeable area i.e. catchment