Changes

==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)==

In some very constrained sites, the surface area of the practice may be limited, in this case the required active storage reservoir depth, d_r of the bioretention cell or infiltration trench can be calculated.

On densely developed sites, the surface area of the practice may be constrained. In such cases the required storage reservoir depth, d_r of the bioretention cell or infiltration trench can be calculated based on available surface area.

Note that in most cases the results of this calculation will be very similar to those from the equation below assuming 3 dimensional drainage.  

:<math>d=\frac{D\left[\left( \frac{Ai}{Ap} \right )i-f' \right]}{n}</math>

:<math>dr=\frac{D\left[\left( \frac{Ai}{Ap} \right )i-f' \right]}{n}</math>

 

==To calculate the required storage reservoir footprint area where the depth is constrained (1D drainage)==

==To calculate the require facility area or footprint 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 this case the required storage needs to be distributed more widely across the landscape. The area of the storage reservoir, A_r can be calculated:

In many locations throughout Ontario, there may be limited depth of soil available into which stormwater may be infiltrated. In this case the required storage needs to be distributed more widely across the landscape. The area of the storage reservoir, A_r can be calculated:

<math>Ar=\frac{iDAi}{ndr+f'D}</math>

<math>Ar=\frac{iDAi}{nd+f'D}</math>

==Time required to drain surface ponded water==

==Time required to drain surface ponded water==