Changes

Jump to navigation Jump to search
Line 65: Line 65:

===Overflow===
===Overflow===
[[File:OverflowEdge.png|frame|Porous asphalt system with overflow edge draining to a reservoir.  A flush curb extending into the base may be required as an edge restraint for some permeable pavement types.  Decorative stone is lined with a geotextile to prevent migration of fine sediment into the pavement base and facilitate maintenance. Source: Pennsylvania Department of Environmental Protection (PDEP). 2006.]]
[[File:OverflowEdge.png|frame|Porous asphalt system with overflow edge draining to a reservoir. Source: Pennsylvania Department of Environmental Protection (PDEP). 2006.]]


All designs require an overflow outlet connected to a storm sewer with capacity to convey larger storms. This is normally achieved with a catch basin outlet, but water may also be directed to a downstream practice (e.g. bioretention, swale). Another option is a gravel diaphragm or trench along the downgradient edge of the pavement that drains to the storage reservoir below.
All designs require an overflow outlet connected to a storm sewer with capacity to convey larger storms. This is normally achieved with a catch basin outlet, but water may also be directed to a downstream practice (e.g. bioretention, swale). Another option is a gravel diaphragm or trench along the downgradient edge of the pavement that drains to the storage reservoir below.
The diagram to the left is an example of a porous asphalt system with overflow edge draining to a reservoir.  A flush curb extending into the base may be required as an edge restraint for some permeable pavement types.  Decorative stone is lined with a geotextile to prevent migration of fine sediment into the pavement base and facilitate maintenance.


===Finish course===
===Finish course===

Navigation menu