Changes

===Overflow elevation===

===Overflow elevation===

The invert of the overflow should be placed at the maximum water surface elevation of the practice. i.e. the maximum surface ponding level.  

The invert of the overflow should be placed at the maximum water surface elevation of the practice. i.e. the maximum surface ponding level.  

A good starting point is 150 to 350 mm above the surface of the mulch cover. However, consideration should be given to public safety, whether or not an underdrain is included, and the time required for ponded water to drain through the filter bed surface, and if no underdrain is present, through the underlying native soil (must drain within 48 hours).  

A good starting point is 150 to 350 mm above the surface of the mulch cover. However, consideration should be given to public safety, whether or not an underdrain is included, the time required for ponded water to drain through the filter bed surface, and if no underdrain is present, into the underlying native soil (must drain within 48 hours).  

See [[Bioretention: Sizing]] and [[Stormwater planters]] for more details.

See [[Bioretention: Sizing]] and [[Stormwater planters]] for more details.