==Determine the required surface area of the practice==
==Determine the required surface area of the practice==
* Step 4: Calculate the surface (i.e footprint) area of the practice (A<sub>p</sub>) needed to capture runoff produced from the catchment during the design storm event:<br>
* Step 4: Calculate the surface (i.e footprint) area of the practice (A<sub>p</sub>) needed to capture the runoff volume produced from the catchment during the design storm event:<br>
For practices where flow is delivered to the filter media bed:
For practices where flow is delivered to the filter media bed: