Changes

===Rapid===

===Rapid===

<p>Total cistern volume can be estimated by multiplying the depth of design storm the catchment area. <br>One millimeter of rain landing on 1 m² results in 1 L of runoff. <br>

<p>Total cistern volume can be estimated by multiplying the depth of design storm the catchment area. <br>One millimeter of rain landing on 1 m² results in 1 L of runoff. <br>

For example, the 90th percentile event in Barrie is 26 mm, so every 1 m² of rooftop will generate 26 L during this storm event.<br> A 2000 m² building would generate approximately 54,000 L during this 26 mm event. <br>

For example, the 90th percentile event in Barrie is 26 mm, so every 1 m² of rooftop will generate 26 L during this storm event.<br> A 2000 m² building would generate approximately 54,000 L. <br>

The designers have three choices:-

The designers have three choices:-

<ol>

<ol>

<li>Construct a suitably sized concrete vault underground to capture all of the water</li>

<li>Construct a suitably sized concrete vault underground to capture all 54,000 L of the water</li>

<li>Alter the slope of the roof to create two or more catchments, the smaller catchments may be diverted to plastic or fiberglass cisterns</li>

<li>Alter the slope of the roof to create two or more catchments, the smaller catchments may be diverted to plastic or fiberglass cisterns</li>

<li>Design 1. or 2. Slightly undersized for this storm, but with additional capacity in an infiltration system to capture overflow. Examples include [[Bioretention Cells|bioretention cells]] or [[Infiltration Chambers|infiltration chambers]]. </li>   

<li>Design 1. or 2. Slightly undersized for this storm, but with additional capacity in an infiltration system to capture overflow. Examples include [[Bioretention Cells|bioretention cells]] or [[Infiltration Chambers|infiltration chambers]]. </li>