Changes

Input data:  

<li>Input data:  

*The applicable infiltration coefficient (''q'') is calculated by applying a [[Infiltration: Testing|safety factor to the measured infiltration rate]].

*Determine the impervious catchment area (''I''), and outline the location of the bioretention facility. To begin with, budget for at least 10% of the total catchment area to be required for the BMP. The area of the facility on the ground will be 'P' (pervious).

<li>The applicable infiltration coefficient (q) is calculated by applying a [[Infiltration: Testing|safety factor to the measured infiltration rate]].</li>

*Unless the biomedia fill material has been tested and certified otherwise, a porosity value (''n'') of 0.35 may be assumed (i.e. void ratio 35%).

<li>Determine the drainage catchment area (A_D), and outline the location of the bioretention facility. To begin with, budget for at least 10% of the contributing impervious area to be required for the BMP. </li></li>

*Bioretention facilities are usually between 0.5 m and 1.25 m deep, owing to construction considerations. Determine the maximum available depth (''c_{c max}'') from the site constraints. The [[Infiltration]] page lists these.  

<li>Unless the biomedia fill material has been tested and certified otherwise, a porosity value (V_r) of 0.4 may be assumed (i.e. void ratio 40%). </li>

Identify the duration (''D'') and intensity (''i'') of design storm(s).

<li>Bioretention facilities are usually between 0.5 m and 1.25 m deep, owing to construction considerations. Determine the maximum available depth (c_{c max}) from the site constraints. The [[Infiltration]] page lists these. </li>

Calculate the required pervious area

<li>Identify the duration (D) and intensity (i) of design storm(s). </li></ul>

 

<li>Calculate the required area</li>

<math>d_{f}=\frac{D\left (\left [ I/P \right ]i-q \right )}{n}</math>

</ol>

 

<strong>[[Media:Infiltration Sizing.xlsx|Download .xlsx calculation tool]]</strong>

<strong>[[Media:Infiltration Sizing.xlsx|Download .xlsx calculation tool]]</strong>

[[category: modeling]]

[[category: modeling]]

[[category: infiltration]]

[[category: infiltration]]