Changes

[[file:Hydraulic radius.png|thumb|Three footprint areas of 9 m².<br>

[[file:Hydraulic radius.png|thumb|Three footprint areas of 9 m².<br>

From left to right x = 12 m, x = 20 m]]<br>

From left to right x = 12 m, x = 20 m]]<br>

For some geometries (e.g. particularly deep facilities or linear facilities), it preferable to account for lateral infiltration.  

For some geometries, particularly deep or linear facilities, it desirable to account for lateral drainage, out the sides of the storage reservoir.  

The 3D equation make use of the hydraulic radius (''A<sub>p''/''x''), where ''x'' is the perimeter (m) of the facility. <br>

The following equation makes use of the hydraulic radius (''A<sub>r''/''x''), where ''x'' is the perimeter (m) of the facility. <br>

'''Maximizing the perimeter of the facility directs designers towards longer, linear shapes such as [[infiltration trenches]] and [[bioswales]].'''<br>

'''Maximizing the perimeter of the water storage reservoir of the facility will enhance drainage performance and directs designers towards longer, linear shapes such as [[infiltration trenches]] and [[bioswales]].''' See illustration for an example.<br>

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To calculate the time (''t'') to fully drain the facility:  

To calculate the time (''t'') to fully drain the facility assuming three-dimensional drainage:  

<math>t=\frac{nAp}{f'x}ln\left [ \frac{\left (d+ \frac{Ap}{x} \right )}{\left(\frac{Ap}{x}\right)}\right]</math>

<math>t=\frac{nAp}{f'x}ln\left [ \frac{\left (d+ \frac{Ap}{x} \right )}{\left(\frac{Ap}{x}\right)}\right]</math>

Where "ln" means natural logarithm of the term in square brackets

Where "ln" means natural logarithm of the term in square brackets