Changes

==Overview==

==Overview==

[[Permeable pavement|Permeable Pavers]] are an alternative to traditional impervious pavements that allow stormwater to drain through them and into a storage reservoir below. Depending on the native soil properties and site constraints, the system may be designed for full infiltration, partial infiltration, or as a non-infiltrating detention and filtration only practice. They can be used for low traffic roads, parking, driveways, and walk ways, and are ideal where space for other surface BMPs is limited. Permeable pavement types include:

[[Permeable pavement|Permeable Pavers]] are an alternative to traditional impervious pavements that allow stormwater to drain through them and into a storage reservoir aggregate layer below. Depending on the native soil properties and site constraints, the system may be designed for full infiltration, partial infiltration, or as a non-infiltrating detention and filtration only practice. They can be used for low traffic roads, parking, driveways, and walk ways, and are ideal where space for other surface BMPs is limited. Permeable pavement types include:

*permeable interlocking pavers (concrete or composite materials)

*permeable interlocking pavers (concrete or composite materials)

*grid systems (concrete or composite materials)

*grid systems (concrete or composite materials)

<small>'''Note:''' Please click on each image to enlarge to view associated construction cost results.</small><br>

<small>'''Note:''' Please click on each image to enlarge to view associated construction cost results.</small><br>

 

Above you can find breakdowns of construction costs by expense type for a pavement consisting of 1,000 m² of permeable interlocking concrete pavers and 1,000 m² of standard asphalt (I:P area ratio of 1:1) for each design configuration:<br>

Above you can find breakdowns of construction costs by expense type for a pavement consisting of 1,000 m2 or porous asphalt and 1,000 m2 of standard asphalt (I:P area ratio of 1:1) for each design configuration:

#[[Permeable pavements#Design|Non-infiltrating/filtration only Permeable Pavement]],  

#[[Permeable pavements#Design|Non-infiltrating/filtration only Permeable Pavement]],  

#[[Permeable pavements#Design|Full infiltration Permeable Pavement]]  

#[[Permeable pavements#Design|Full infiltration Permeable Pavement]]  

As can be seen, regardless of outlet configuration, Material & Installation expenses represent the largest portion of the total construction costs (82 to 85%). These include costly components such as the, [[Liner|impermeable membrane/liner]], the [[underdrain]], the [[Permeable pavements#Foundation Aggregates|sub-base]] layer of 50 mm dia. [[clear stone]], base layer of 19 mm dia. [[clear stone]], [[Bedding layer|bedding layer]] and interlocking pavers.

As can be seen, regardless of outlet configuration, Material & Installation expenses represent the largest portion of the total construction costs (82 to 85%). These include costly components such as the [[Liner|impermeable membrane/liner]], [[underdrain]], [[Permeable pavements#Foundation Aggregates|sub-base layer]] of 50 mm dia. [[clear stone]], [[Permeable pavements#Foundation Aggregates|base layer]] of 19 mm dia. [[clear stone]], [[Bedding layer|bedding layer]] of 5 mm dia. [[clear stone]] and interlocking pavers themselves.

==Life Cycle Costs==

==Life Cycle Costs==

Below are capital and life cycle cost estimates for the three [[permeable pavements|permeable pavement]] configurations over 25- and 50-year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values.  Operation and maintenance costs are predicted to represent between 18 to 20% of total life cycle costs over the 25-year evaluation period, and increase to between 26 to 29% of total life cycle costs over the 50-year period, due to costs associated with restriping, replacement of limited number of pavers and flushing of underground pipes (underdrain and overflow) after 25 years of operation.  Estimates assume no rehabilitation of the permeable pavement surface to maintain acceptable drainage performance is required over the 50 year timeframe.

Below are capital and life cycle cost estimates for the three [[permeable pavements|permeable pavement]] configurations over 25- and 50-year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values.  Operation and maintenance costs are predicted to represent between 18 to 20% of total life cycle costs over the 25-year evaluation period, and increase to between 26 to 29% of total life cycle costs over the 50-year period, due to costs associated with restriping, replacement of limited number of pavers and flushing of underground pipes (underdrain and overflow) after 25 years of operation.  Estimates assume no rehabilitation of the permeable pavement surface is required to maintain acceptable drainage performance over the 50 year timeframe.

<small>'''Note:''' Please click on each image to enlarge to view associated life cycle cost results.</small><br>

<small>'''Note:''' Click on each image to enlarge to view associated life cycle cost results.</small><br>

===50-Year life cycle cost break down===

===50-Year life cycle cost break down===

<small>'''Note:''' Please click on each image to enlarge to view associated life cycle cost results.</small><br>

<small>'''Note:''' Click on each image to enlarge to view associated life cycle cost results.</small><br>

==Cost Summary Table ==

==Cost Summary Tables==

Total life cycle cost estimates for the three permeable pavement configurations vary substantially with the No Infiltration design being highest ($187,356.33), compared to the Partial Infiltration design ($168,085.10), and followed closely by the Full Infiltration design ($162,491.78).

Total life cycle cost estimates over the 50 year evaluation period for the three permeable pavement configurations vary substantially with the No Infiltration design being highest ($262,294.27), compared to the Partial Infiltration design ($242,444.90), and followed closely by the Full Infiltration design ($234,854.66).

It is notable that a sensitivity analysis was conducted in 2019 to compare construction cost estimates generated by the tool to actual costs of implemented projects. '''The analysis found that tool estimates were typically within ±14% of actual construction costs'''<ref>Credit Vally Conservation (CVC). 2019. Life-cycle costing tool 2019 update: sensitivity analysis. Credit Valley Conservation, Mississauga, Ontario. https://sustainabletechnologies.ca/app/uploads/2020/04/LCCT-Sensitivity-Analysis_March2020.pdf</ref>.

It is notable that a sensitivity analysis was conducted in 2019 to compare construction cost estimates generated by the tool to actual costs of implemented projects. '''The analysis found that tool estimates were typically within ±14% of actual construction costs'''<ref>Credit Vally Conservation (CVC). 2019. Life-cycle costing tool 2019 update: sensitivity analysis. Credit Valley Conservation, Mississauga, Ontario. https://sustainabletechnologies.ca/app/uploads/2020/04/LCCT-Sensitivity-Analysis_March2020.pdf</ref>.

[[File:PICPchicago.jpg|thumb|500px||Permeable Interlocking Concrete Pavement (PICP) on a narrow road between buildings in Chicago (Source: ICPI)]]

[[File:PICPchicago.jpg|thumb|500px||Permeable Interlocking Concrete Pavement (PICP) on a narrow road between buildings in Chicago (Source: ICPI)]]

[[File:Design Table PP Full Infil.PNG|700px]]<br>

[[File:Design Table PP Full Infil Update 2023.PNG|700px]]<br>

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===Partial Infiltration===

===Partial Infiltration===

[[File:Design Table PP Partial Infil.PNG|700px]]<br>

[[File:Design Table PP Partial Infil update 2023.PNG|700px]]<br>

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===Non-Infiltrating/filtration only===

===Non-Infiltrating/filtration only===

[[File:Design Table PP No Infil.PNG|700px]]<br>

[[File:Design Table PP No Infil update 2023.PNG|700px]]<br>

==References==

==References==