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mLine 31:
Line 31: − + − + − *''SCF'' = Safety correction factor+ − + − − *''A<sub>p</sub>'' = Area of the infiltration practice in m<sup>2</sup> − *''A<sub>c</sub>'' = Catchment area in m<sup>2</sup> − *''d'' = Depth of infiltration practice in m.}}
→Size a bioretention cell for constrained ground area
Then calculate the required depth (d<sub>T</sub>), as:
Then calculate the required depth (d<sub>T</sub>), as:
<math>d=\frac{D \left[ (R\times i)-f'\right]}{V_{R}}</math>
<math>d_{T}=\frac{D \left[ (R\times i)-f'\right]}{V_{R}}</math>
{{Plainlist|1=Where:
{{Plainlist|1=Where:
*''D'' = Duration of design storm in hrs
*''D'' = Duration of design storm in hrs
*''i'' = Intensity of design storm in mm/hr
*''i'' = Intensity of design storm in mm/hr
*''q''' = Infiltration coefficient in mm/hr (accounting for SCF)
*''f''' = Design infiltration rate in mm/hr
*''V<sub>R</sub>'' = Void ratio
*''V<sub>R</sub>'' = Void ratio (porosity), as measured (or default to 0.35 for all aggregates)
*''d<sub>T</sub>'' = Depth of infiltration practice in m.}}
*''R'' = Ratio of catchment area (''A<sub>c</sub>'') to BMP footprint area (A<sub>p</sub>) syn. I/P ratio.
The following equations assume that infiltration occurs primarily through the base of the facility.
The following equations assume that infiltration occurs primarily through the base of the facility.
They may be easily applied for any shape and size of infiltration facility, in which the reservoir storage is mostly in an aggregate.
They may be easily applied for any shape and size of infiltration facility, in which the reservoir storage is mostly in an aggregate.