Changes

The value for native soil infiltration rate (q) used in the above equations should be the design [[infiltration]] rate that incorporates a safety correction factor based on the ratio of the mean value at the proposed bottom elevation of the practice to the mean value in the least permeable soil horizon within 1.5 metres of the proposed bottom elevation.  

The value for native soil infiltration rate (q) used in the above equations should be the design [[infiltration]] rate that incorporates a safety correction factor based on the ratio of the mean value at the proposed bottom elevation of the practice to the mean value in the least permeable soil horizon within 1.5 metres of the proposed bottom elevation.  

On highly permeable soils (e.g., infiltration rate of 45 mm/hr or greater), a maximum stone reservoir depth of 2 metres is recommended to prevent soil compaction and loss of permeability from the mass of overlying stone and stored water.  

On highly permeable soils (e.g., infiltration rate of 45 mm/hr or greater), a maximum stone reservoir depth of 2 metres is recommended to prevent soil compaction and loss of permeability from the mass of overlying stone and stored water.  

If trying to size the area of permeable paving based on the contributing drainage area, the following equation may be used:

When sizing the area of permeable paving based on the contributing drainage area, the following equation may be used:

<math>A_p= \frac{Q_c\times A_c}{Vr \times dp – P + q\times T}</math>

<math>A_p= \frac{Q_c\times A_c}{Vr \times dp – P + q\times T}</math>

[[category:modeling]]

[[category:modeling]]