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| *Step 1: Determine what the planting needs are and assign appropriate depth of media. | | *Step 1: Determine what the planting needs are and assign appropriate depth of media. |
| *Step 2: Decide on the underdrain pipe diameter. | | *Step 2: Decide on the underdrain pipe diameter. |
− | *Step 3: Determine maximum possible storage reservoir depth beneath the pipe (''d<sub>S</sub>''): | + | *Step 3: Determine maximum possible storage reservoir depth beneath the pipe (''d<sub>s</sub>''): |
− | <math>d_{S}=f'\times38.4</math> | + | <math>d_{s}=f'\times38.4</math> |
| {{Plainlist|1=Where: | | {{Plainlist|1=Where: |
| *''f''' = Design infiltration rate in mm/hr, and | | *''f''' = Design infiltration rate in mm/hr, and |
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| | | |
| ===Additional step for system without underdrain=== | | ===Additional step for system without underdrain=== |
− | *Step 4: Determine maximum permissible ponding depth (''d<sub>P</sub>''): | + | *Step 4: Determine maximum permissible ponding depth (''d<sub>p</sub>''): |
− | <math>d_{P}=f'\times19.2</math> | + | <math>d_{p}=f'\times19.2</math> |
| {{Plainlist|1=Where: | | {{Plainlist|1=Where: |
| *''f''' = Design infiltration rate in mm/hr, and | | *''f''' = Design infiltration rate in mm/hr, and |
| *19.2 comes from multiplying desired drainage time of 48 hours by void ratio of 0.4. Note that conceptually the drainage of the ponded area is limited by ex-filtration at the base of the practice.}} | | *19.2 comes from multiplying desired drainage time of 48 hours by void ratio of 0.4. Note that conceptually the drainage of the ponded area is limited by ex-filtration at the base of the practice.}} |
− | * Step 5: Sum total depth of bioretention and compare to available space above water table and bedrock. Adjust if necesary. | + | * Step 5: Sum total depth of bioretention and compare to available space above water table and bedrock. Adjust if necesary. |
| | | |
| ==Calculate the remaining dimensions== | | ==Calculate the remaining dimensions== |