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Vegetated Filter Strip Design Manual
Design Guide

Author: Robert P. Stone, P. Eng., Engineer, Soil/OMAFRA
Creation Date: 14 September 2005
Last Reviewed: 16 August 2007

| Introduction and Background | General Design Guidance for VFS System Components |
| Design Guidelines of VFS System Components |
| Design Guide | Case Studies | Design Tables | Glossary |

| Runoff Collection Area | Storage Settling Basin | Runoff Collection/Discharge Bay |
| Conveyance Pipe | Distribution Pipe | Infiltration Area |


Design Guide
Infiltration Area

Step

Description

Method/Design Parameter

 Equation Variables

Value

 Units

Example
6.1 Determine minimum infiltration area required based on saturated hydraulic conductivity (Stage 1) Determine the saturated hydraulic conductivity for the infiltration area soil Minimum infiltration area = target flow rate (Step 4.5) saturated hydraulic conductivity y In-situ determination of saturated hydraulic conductivity required   m2  
6.2 Determine minimum infiltration area required based on liquid loading (Stage 2) Use Table 3.2 to obtain highest normal monthly precipitation for closest station   Maximum allowable liquid loading is 5 cm/week including rainfall   m/
month
  
Calculate highest normal weekly precipitation (highest normal monthly precipitation/4)
   Closest rainfall station is provided in Table 3.3   m/
week
  
Calculate outside paved yard weekly runoff volume.   Multiply the paved yard area by the highest normal weekly precipitation   m3

 
Calculate limiting precipitation amount per week on VFS.   The limiting precipitation amount per week is [5 cm minus highest normal weekly precipitation]   m

 
Calculate minimum VFS area required.   The yard weekly runoff volume is divided by the limiting precipitation amount per week on VFS   m2

 
6.3 Determine minimum infiltration area from Stage 1 (Step 6.1) and Stage 2 (Step 6.2) Select larger infiltration area from Step 6.1 and Step 6.2.       m2  
6.4 Determine minimum length of infiltration area Use Table 3.4 and VFS slope.       m  
6.5 Determine minimum width of infiltration area Use Equation 3.10.   Flow depth is 0.0127 m and flow velocity is found in Table 3.4   m  
6.6 Calculate actual infiltration area dimensions Select largest infiltration area from Stage 1 (Step 6.1) or Stage 2 (Step 6.2).   Minimum length of infiltration area comes from Step 6.4 (final width must be equal to or greater than distance calculated in Step 6.5)   m2

 
6.7 Determine final dimensions of infiltration area See Step 6.6 for final dimensions of infiltration area.   Final infiltration area dimensions L =
W =
A =
m
m
m2

 

| Top of Page |

| Introduction and Background | General Design Guidance for VFS System Components |
| Design Guidelines of VFS System Components |
| Design Guide | Case Studies | Design Tables | Glossary |

| Top of Page |

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