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Line 5:
where:{{plainlist|}}
<math>d= \frac{[Qc\times R + P - q\times T ]}{Vr}</math>
<math>d= \frac{[Qc\times R + P - q\times T ]}{Vr}</math>
{{Plainlist|1=Where:
*''d'' = Stone bed depth (m)
*''d'' = Stone bed depth (m)
*''Qc'' = Depth of runoff from contributing drainage area, not including permeable paving surface(m)
*''Q<sub>c</sub>'' = Depth of runoff from contributing drainage area, not including permeable paving surface(m)
*''R'' = A<sub>c</sub>/A<sub>p</sub> = Ratio of contributing drainage area (A<sub>c</sub>) to permeable paving area (A<sub>p</sub>)
*''R'' = A<sub>c</sub>/A<sub>p</sub> = Ratio of contributing drainage area (A<sub>c</sub>) to permeable paving area (A<sub>p</sub>)
*''P'' = Rainfall depth (m)
*''P'' = Rainfall depth (m)
*''q'' = Infiltration rate for native soils (m/day)
*''q'' = Infiltration rate for native soils (m/day)
*''T'' = Time to fill stone bed (typically 2 hr)
*''T'' = Time to fill stone bed (typically 2 hr)
*''Vr'' = Void ratio for stone bed (typically 0.4 for 50 mm dia. stone)
*''Vr'' = Void ratio for stone bed (typically 0.4 for 50 mm dia. stone)}}
Note that the contributing drainage area (Ac) should not contain pervious areas.
Note that the contributing drainage area (Ac) should not contain pervious areas.