Changes

==Time required to drain surface ponded water (1D drainage)==

==Time required to drain surface ponded water (1D drainage)==

The following equation assumes one dimensional drainage over the surface ponding area.

The following equation assumes one dimensional drainage over the surface ponding area.

It is best applied to calculate the maximum duration of ponding on the surface of [[Bioretention |bioretention cells]] and [[Stormwater Tree Trenches |stormwater tree trenches]], and upstream of [[check dams]] of [[bioswales]] and [[enhanced grass swales]] to ensure all surface ponding drains within 24 hours.  

It is best applied to calculate the maximum duration of ponding on the surface of [[Bioretention |bioretention cells]] and [[Stormwater Tree Trenches |stormwater tree trenches]], and upstream of check dams of [[bioswales]] and [[enhanced grass swales]] to ensure all surface ponding drains within 24 hours.  

To calculate the time (''t'') to fully drain surface ponded water through the filter media or planting soil:  

To calculate the time (''t'') to fully drain surface ponded water through the filter media or planting soil:  

<math>t=\frac{d_{p}'}{K_{f}}</math>

<math>t=\frac{d_{p}'}{K_{f}}</math>