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Line 70: − − ==To calculate the required storage reservoir footprint area where the depth is constrained (1D drainage)== − In many locations throughout Ontario, there may be limited depth of soil available into which stormwater may be infiltrated. In such cases the required storage needs to be distributed more widely across the landscape. The footprint area of the water storage reservoir, A<sub>r</sub> can be calculated: − <math>Ar=\frac{iDAi}{nd+f'D}</math>
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This spreadsheet tool has been set up to perform all of the infiltration practice sizing calculations shown below<br>
This spreadsheet tool has been set up to perform all of the infiltration practice sizing calculations shown below<br>
{{Clickable button|[[Media:Infiltration Sizing 20200525 locked.xlsx|Download the infiltration practice sizing tool]]}}
{{Clickable button|[[Media:Infiltration Sizing 20200525 locked.xlsx|Download the infiltration practice sizing tool]]}}
==To calculate the required storage reservoir footprint area where the storage reservoir depth is fixed or constrained (1D drainage)==
To ensure that the water storage capacity of the facility is available at the onset of a storm event, it is recommended to size the storage reservoir based on the depth of water that will drain via infiltration between storm events. So d<sub>r</sub> can be calculated as:<br>
''d<sub>r</sub> = (f'/1000) * t <br>
Where <br>
f' = design infiltration rate of the native soil (mm/h) <br>
t = drainage time, based on local criteria or average inter-event period.<br>
<br>
In many locations there may be a limited depth of soil available above the seasonally high water table or top of bedrock elevation into which stormwater may be infiltrated. In such cases the required storage needs to be distributed more widely across the landscape. <br>
Where the storage reservoir depth is fixed or constrained he footprint area of the water storage reservoir, A<sub>r</sub> can be calculated:
<math>Ar=\frac{iDAi}{nd+f'D}</math>
==To calculate the required storage reservoir depth where the area of the facility is constrained (1D drainage)==
==To calculate the required storage reservoir depth where the area of the facility is constrained (1D drainage)==
:<math>d=\frac{D\left[\left( \frac{Ai}{Ap} \right )i-f' \right]}{n}</math>
:<math>d=\frac{D\left[\left( \frac{Ai}{Ap} \right )i-f' \right]}{n}</math>
Note that in most cases the results of this calculation will be very similar to those from the equation below assuming 3 dimensional drainage.
Note that in most cases the results of this calculation will be very similar to those from the equation below assuming 3 dimensional drainage.
==To calculate the required storage reservoir depth, where the area of the facility is constrained (3D drainage)==
==To calculate the required storage reservoir depth, where the area of the facility is constrained (3D drainage)==