Permeable Pavements
Shingle Creek Watershed Management Commission
May 31, 2011
Outline
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Purpose of presentation
Types of pavements and applications
Benefits
Design considerations
Maintenance considerations
Example projects
Questions
Types of Permeable
Pavements
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Porous Asphalt
Pervious Concrete
Pervious Pavers
Permeable pavement has pores or
openings that allow water to pass
through the surface and stone base
material and infiltrate into the
underlying soils.
Porous Asphalt
Pervious Pavers
Pervious Concrete
Pervious Pavement
Hydrology
Porous HMA (or Dense HMA with Piping)
John Barten, second from right, riding on
pervious pavement in Medina around
1905.
Water Storage in Pervious
Concrete System
Porous Asphalt Section
Pervious Concrete Paver
Project Applications
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Streets
Parking lots
Sidewalks and paths
Driveways
Patios
Playgrounds
Potential Benefits
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Reduces the rate and quantity of
stormwater runoff
Reduces stress on the sewer system
Recharges groundwater
Filters out silt, pollutants, and debris
Maintains natural drainage paths
Reduces standing water nuisance
Potential Benefits
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Reduces stormwater infrastructure
needs (pipes, ponds, catch basins)
Offers good alternative to conventional
stormwater mitigation
Better erosion control
Reduces ice buildup and need for
salting during the winter
Provides better traction
Design Considerations
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Soils
Depth to groundwater
Traffic loading
Slopes
Blowing dust and debris
Design Considerations
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Unique site features
Agency stormwater regulations
Frost penetration
Permeable Pavement
Limitations
Use of permeable pavement is not
recommended in the following cases:
 Industrial “brownfield sites or sites
with contaminated soils
 Where site layouts direct clogging
sediment on the pavement surface
 Sites with excessively steep grades
Maintenance
Considerations
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Protect pavement from silt and
sediment during and after construction
Vacuum sweep at least twice a year
Do not seal coat
Do not sand
Use caution when snowplowing
Post signs advising maintenance crews
Maintenance
Considerations
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Perform periodic inspections; look for
clogging, raveling, cracking, and wear
Other???
Ongoing Maintenance Vacuum Sweeping
Sweepings
Maintenance Warning
Signs
Paired Intersection
Study, Robbinsdale, MN
Porous asphalt test section - Abbott/41st , 2009
Porous Subgrade
Preparation
Porous Asphalt Placement
Cost
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Test section = 150 feet long, 27 feet
wide
Traditional pavement, contract unit
prices = $14,125 =$32/SY
Porous pavement
– Site 1 = $42,670
– Site 2 = $32,200
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“Upcost” = $35-50/SY
Residential Street Paving
Project, Shoreview, MN
Lake Owasso
Asphalt replaced with pervious concrete, 2009
Water Infiltration Demo
http://www.youtube.com/watch?v=j_z0xRPbExY
Shoreview Water
Infiltration Demo
Pervious Concrete Cost
Comparison
Common Excavation – 11,000CY($6.00/CY)
Fabric – 11,000SY($1.00/SY)
1-1/2” Crushed Rock – 5000CY($52.00/CY)
7” Pervious Concrete – 8470SY($46.50/SY)
Total Cost for Pervious Concrete System
Per SY Cost for Pervious Concrete System
*Average depth beneath concrete = 1.75-feet
= $ 66,000*
= $ 11,000
= $260,000*
= $394,000
= $731,000
= $ 86.30**
Estimated Bituminous Road Cost
Estimated Underground Infiltration Cost
Total Est Cost – Bit Road & Infiltration
Per SY Est Cost – Bit Road & Infiltration
= $257,000
= $417,500
= $674,000
= $ 79.60**
**8.5% Increased Cost for Pervious Concrete
Wolner Field Parking Lot,
Mound, MN
Before
After
Asphalt replaced with pervious concrete and draintile, 2007
Pavement Cost
Comparison
Mound Transit Center,
Mound, MN
Installed pervious pavers, 2007
Subgrade preparation
Little Six Casino, Prior
Lake, MN
Porous asphalt pavement in parking lot, 2009
Brainerd Area
Porous asphalt parking lot, 2006
• You've carefully thought out all the angles.
• You've done it a thousand times.
• It comes naturally to you.
• You know what you're doing, its what
you've been trained to do your whole life.
• Nothing could possibly go wrong, right ?