Changes

*Step 1: Determine what the planting needs are and assign appropriate depth of media, using the table above.  

*Step 1: Determine what the planting needs are and assign appropriate depth of media, using the table above.  

*Step 2: Select an underdrain pipe diameter (typically 100 - 200 mm), assign this as an 'embedding' depth. *Note that this component does not apply if a downstream riser is being used to control an extended saturation zone.   

*Step 2: Select an underdrain pipe diameter (typically 100 - 200 mm), assign this as an 'embedding' depth. *Note that this component does not apply if a downstream riser is being used to control an extended saturation zone.   

*Step 3: Calculate the maximum possible storage reservoir depth beneath the pipe (''d_{s, max}'', mm):

*Step 3: Calculate the maximum permissible water storage depth beneath the pipe (''d_{s, max}'', mm):

<math>d_{s, max}=f'\times t</math>

<math>d_{s, max}=f'\times t</math>

{{Plainlist|1=Where:

{{Plainlist|1=Where:

{{Plainlist|1=Where:

{{Plainlist|1=Where:

*''f''' = Design infiltration rate (mm/hr), and

*''f''' = Design infiltration rate (mm/hr), and

*48 = Maximum allowable drainage time for ponded water (hrs)

*48 = Maximum permissible drainage time for ponded water (hrs)

*Note that in designs without underdrains, conceptually the drainage of ponded water is limited by exfiltration at the base of the practice.}}

*Note that in designs without underdrains, conceptually the drainage of ponded water is limited by exfiltration at the base of the practice.}}

* Step 5: Sum total depth of bioretention, and compare to available depth above the seasonally high water table and/or bedrock elevation. Adjust if necessary.

* Step 5: Sum total depth of bioretention, and compare to available depth above the seasonally high water table and/or bedrock elevation. Adjust if necessary.