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==Size a bioretention cell for constrained depth==
 
==Size a bioretention cell for constrained depth==
Determine if there is a constraint to the depth (''d<sub>T</sub>'') of the bioretention practice:
   
{{:Depth to GW}}
 
{{:Depth to GW}}
|'''or''' if the land area is limited, determine the I/P ratio::<math>R=\frac{A_{c}}{A_{p}}</math>
+
If there is a constraint to the depth (''d<sub>T</sub>'') of the bioretention practice calculate the require facility area or footprint where the depth is constrained, as:
 +
<math>A_{p}=\frac{IiD}{V_{R}d+f'D}</math>
 +
{{Plainlist|1=Where:
 +
*''D'' = Duration of design storm in hrs
 +
*''i'' = Intensity of design storm in mm/hr
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*''f''' = [[design infiltration rate]] in mm/hr
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*''V<sub>R</sub>'' = Void ratio (porosity), as measured (or default to 0.35 for all aggregates)
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*''R'' = Ratio of catchment area (''A<sub>c</sub>'') to BMP footprint area (A<sub>p</sub>).
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*''A<sub>p</sub>'' = Area of the infiltration practice in m<sup>2</sup>
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*''A<sub>c</sub>'' = Catchment area in m<sup>2</sup>
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*''d<sub>T</sub>'' = Total depth of the infiltration practice in m.}}
 +
 
 +
==Size a bioretention cell for constrained ground area==
 +
If the land area is limited, determine the ratio:
 +
:<math>R=\frac{A_{c}}{A_{p}}</math>
 +
 
 
{{Plainlist|1= Where:
 
{{Plainlist|1= Where:
 
*''R'' = Ratio of catchment area (''A<sub>c</sub>'') to BMP footprint area (A<sub>p</sub>) syn. I/P ratio.   
 
*''R'' = Ratio of catchment area (''A<sub>c</sub>'') to BMP footprint area (A<sub>p</sub>) syn. I/P ratio.   
 
*''A<sub>p</sub>'' = Area of the infiltration practice in m<sup>2</sup>
 
*''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>}}
 
*''A<sub>c</sub>'' = Catchment area in m<sup>2</sup>}}
|-
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!colspan="2" style="text-align: center;"|Then
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Calculate the required depth (d<sub>T</sub>), as:
|-
  −
|To calculate the require facility area or footprint where the depth is constrained:
  −
<math>A_{p}=\frac{IiD}{V_{R}d+q'D}</math>
  −
|To calculate the required depth, where the area of the facility is constrained:
   
<math>d=\frac{D\left[Ri-q'\right]}{V_{R}}</math>
 
<math>d=\frac{D\left[Ri-q'\right]}{V_{R}}</math>
 
{{#widget:WolframAlpha|id=88d135fd5507a36a9770deaa8106c975}}
 
{{#widget:WolframAlpha|id=88d135fd5507a36a9770deaa8106c975}}
|}
+
 
 
{{Plainlist|1=Where:
 
{{Plainlist|1=Where:
 
*''D'' = Duration of design storm in hrs
 
*''D'' = Duration of design storm in hrs
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