Sustainable Drainage System Terms A-Z
P
pavement
Technical name for the road or car park surface and underlying structure, usually asphalt, concrete or blockpaving. NB the path next to the road for pedestrians (colloquially called pavement) is properly termed the footway.
permeability
A measure of the ease with which a fluid can flow through a porous medium. It depends on the physical properties of the medium, for example grain size, porosity and pore shape.
permeable pavement
A paved surface that allows the passage of water through voids between the paving blocks/slabs.
permeable surface
A surface formed of material that is itself impervious to water but, by virtue of voids formed through the surface, allows infiltration of water to the sub-base through the pattern of voids, eg concrete block paving.
pervious surface
A surface that allows inflow of rainwater into the underlying construction or soil.
piped system
Conduits generally located below ground to conduct water to a suitable location for treatment and/or disposal.
pollution
A change in the physical, chemical, radiological or biological quality of a resource (air, water or land) caused by man or man’s activities that is injurious to existing, intended or potential uses of the resource.
pond
Permanently wet basin designed to retain stormwater and permit settlement of suspended solids and biological removal of pollutants.
porous paving
A permeable surface allowing the passage of water through voids within, rather than between, the paving blocks/slabs.
porous surface
A surface that infiltrates water to the sub-base across the entire surface of the material forming the surface, for example grass and gravel surfaces, porous concrete and porous asphalt.
pound
A section of a swale designed to detain runoff.
prevention
Site design and management to stop or reduce the occurrence of pollution and to reduce the volume of runoff by reducing impermeable areas.
proper outfall
An outfall to a watercourse, public sewer and in some instances an adopted highway drain. Under current legislation and case law, the existence of a proper outfall is a prerequisite in defining a sewer.
public sewer
A sewer that is vested in and maintained by a sewerage undertaker. |
