The following equation assumes that infiltration occurs primarily through the footprint of the facility.
The following equation assumes that infiltration occurs primarily through the footprint of the facility.
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It is best applied to calculate the maximum duration ponding on the surface of [[bioretention cells]], [[bioswales]] and [[enhanced grass swales]] to ensure it will drain within 48 hours.
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It is best applied to calculate the maximum duration of ponding on the surface of [[bioretention cells]], [[bioswales]] and [[enhanced grass swales]] to ensure all surface ponding drains within 48 hours.
To calculate the time (''t'') to fully drain the facility through the footprint area only:
To calculate the time (''t'') to fully drain the facility through the footprint area only: