Download - Permeable Pavements
Outline
Purpose of presentation Types of pavements and
applications Benefits Design considerations Maintenance considerations Example projects Questions
Types of Permeable Pavements
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.
Potential Benefits
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
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
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 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 Perform periodic inspections; look
for clogging, raveling, cracking, and wear
Other???
Cost
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
“Upcost” = $35-50/SY
Residential Street Paving Project, Shoreview, MN
Lake Owasso
Asphalt replaced with pervious concrete, 2009
Pervious Concrete Cost ComparisonCommon Excavation – 11,000CY($6.00/CY) = $
66,000*Fabric – 11,000SY($1.00/SY) = $ 11,0001-1/2” Crushed Rock – 5000CY($52.00/CY) = $260,000*7” Pervious Concrete – 8470SY($46.50/SY) =
$394,000Total Cost for Pervious Concrete System =
$731,000Per SY Cost for Pervious Concrete System = $
86.30** *Average depth beneath concrete = 1.75-feet
Estimated Bituminous Road Cost = $257,000Estimated Underground Infiltration Cost = $417,500Total Est Cost – Bit Road & Infiltration = $674,000Per SY Est Cost – Bit Road & Infiltration = $
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
• 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 ?