Talk:Permeable Pavement Design Guide

LID Practice		CANADA				United States
Permeable Pavement		CVC+TRCA (Factsheets-2010)	Toronto- 2016	LID-SWM Guide 2010	LID-Design Guide Edmonton- 2014	New York State SWM Design Manual-2015	Massachusets SW BMP-2013	District of Columbia-SWM Guidebook-2010	San Diego LID Handbook-2014	Alabama LID Handbook-2013	W. Virginia-SWM design guidance manual-2012	Rhode Island-SW design & Installation Standards Manual-2012	Minnesota SW Manual-2016	Tennessee-LID Development-SWM 2016	Texas-LID Technical Guidance Manual-2013
(Impervious /permeable pavemet) area		<= 1.2		<= 1.2	< =3.0	Limit CDA to small adjacent impervious area		2-5 X the SA of PP	2:1	3:1	2:1	DA nolimit, runoff from surrounding areas minimized	2:1-5:1 Note 1	L1- 1:1, L2- No IP Note 2	1:1
Depth to high water table (m)		1		at least 1	0.6-1.0
Slope of permeable pavement surface (%)		1-5		1-5	0.5-2.0
A capped vertical sandpipe, perfored instaled to the bottom of the facility to monitor drainage time		100-150 mm
Botom slope if the system is not designed for infiltratin (%)		1-5		1-5
Drainage time of the pavement reservoir after the storm event		< 72 hr		recommended 48
Setback from building Foundation(m)		4		4
Material
Pervious Concrete
Compressive strength (Mpa)		5.5-20					PA and PC must have 10-25% VS,sub-base 40% VS			PC VS:15-25%; PA VS: 15-20%; PICP VS:8-20%; CGP VS:20-50%	PICP OA: 5-15%, CGP OVC: 20-50%; PC VC:15-25%; PA VC: 15-20%	PA/PC: 10-25% void space, pavers 15% void ratio
Void ratio (%)		14-31	15-25	14-31
Permeability (mm/hr)		900-21500	900-21500
Thickness (mm)		100-150	100-150	100-150
Porous Asphalt
Air voids (%)		min. 16	min. 16	min. 16
Thickness (mm)		50-100	50-100	50-100
Permeable Pavers
Diameter of crushed aggregate (mm)		5		5
Thickness for vehicular applications (mm)		80		80
Thickness for pedistrian applications (mm)		60		60
Joint widths for pedistrian applications (mm)		< 15		< 15
Interlocking concrete pavers
Thickness (mm)			60-80
Stone reservoir
Filter course diameter					10-12 mm
Depth below base pf pavement					25-30
Depth below subbase, mm					50-500
Subbase diameter					25-40 mm
Depth below filter course					50-250 mm
Granular subbase stone diameter (mm)		50	50	50	> 50
Void space ratio		0.4		0.4
Granular base stone diameter (mm)		20
Void space ratio			0.3-0.4
Bedding stone diameter (mm)		5	5	5
Time to drain stone bed, hr			24-72
Thickness (mm)		40-75	40-75	40-75
Geotextile
Between stone reseroir and native soil
Underdrain (optional), infiltratio rate <15 mm/hr
Diameter (mm)		>= 100	> 200	>= 100
Diameter of perforations in pipes (mm)		10		10
Above the bottom of the gravel layer (mm)			100
Facilties reciving road runoff are not located within time of travel wellhead protection areas, year		2		2
Subsoil infiltration rate, mm/hr.					>= 13
When contact with anti-skid material					>= 26
When contributing area > 4 hectares					>=35
Emptying Time, hrs.					< 72

- Note 1: IP ratio increases when clean roof runoff, or if runoff pre-treated; PICP OA: 5-15%, PC VC:15-35%; PA VC:16-20% - Note 2: L1-45% runoff reduction credit, L2-75%; PICP: 5-15% OA; CGP: 20-50% OVC; PC: 15-25%; PA: 15-20%

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Credit Valley Conservation

Toronto and Region Conservation Authority

Stormwater Management

Best management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.

A hard surface area (e.g., road, parking area or rooftop) that prevents or retards the infiltration of water into the soil.

A hard surface area (e.g., road, parking area or rooftop) that prevents or retards the infiltration of water into the soil.

The portion of water precipitated onto a catchment area, which then flows as surface discharge from the catchment area past a specified point.

Water from rain, snow melt, or irrigation that flows over the land surface.

The upper surface of the zone of saturation, except where the surface is formed by an impermeable body.

Subsurface water level which is defined by the level below which all the spaces in the soil are filled with water; The entire region below the water table is called the saturated zone.

An alternative practice to traditional impervious pavement, prevents the generation of runoff by allowing precipitation falling on the surface to infiltrate through the surface course into an underlying stone reservoir and, where suitable conditions exist, into the native soil.

The period between the maximum water level and the minimum level (dry weather or antecedent level).

The period between the maximum water level and the minimum level (dry weather or antecedent level).

The void ratio (e) of a mixture is the ratio of the volume of void-space to the volume of solids. It is closely related to the concept of porosity (n) where porosity is the ratio of the volume of void-space to the total or bulk volume of the mixture. e = Volume of voids/Volume of solids = n/(1-n)

The void ratio (e) of a mixture is the ratio of the volume of void-space to the volume of solids. It is closely related to the concept of porosity (n) where porosity is the ratio of the volume of void-space to the total or bulk volume of the mixture. e = Volume of voids/Volume of solids = n/(1-n)

A mixture of mineral aggregates bound with bituminous materials, used in the construction and maintenance of paved surfaces.

A broad category of particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and available in various particulate size gradations.

An underlying bed filled with aggregate or other void-forming fill material that temporarily stores stormwater before infiltrating into the native soil or being conveyed by an underdrain pipe.

Gravel, or crushed stone of various size gradations (i.e., diameter), used in construction; void forming material used as bedding and runoff storage reservoirs and underdrains in stormwater infiltration practices.

The void ratio (e) of a mixture is the ratio of the volume of void-space to the volume of solids. It is closely related to the concept of porosity (n) where porosity is the ratio of the volume of void-space to the total or bulk volume of the mixture. e = Volume of voids/Volume of solids = n/(1-n)

Filter fabric that is installed to separate dissimilar soils and provide runoff filtration and contaminant removal benefits while maintaining a suitable rate of flow; may be used to prevent fine-textured soil from entering a coarse granular bed, or to prevent coarse granular from being compressed into underlying finer-textured soils.

The natural ground material characteristic of or existing by virtue of geographic origin.

A perforated pipe used to assist the draining of soils.

The rate at which stormwater percolates into the subsoil measured in inches per hour.