Usage: Distinctive*
Permeable Interlocking Concrete Pavers (PICPs) have voids at the joints to allow water to pass through into an open-graded reservoir below.
*PICPs have been approved as Standard for use on sidewalks at school locations in lieu of a planting strip. (See: Adopted Zoning Text Amendment 26-421, adopted April 30, 2012.) In addition, PDC has approved this treatment for use in the furnishing zone of city sidewalks. In all cases, PICPs are considered a Distinctive material, and require a maintenance agreement.
Varick Street, Manhattan
Permeable Interlocking Concrete Pavers (PICP)
Benefits
- Reduces impermeable surface, thereby increasing water infiltration
- Reduces peak sewer discharge during storm events
- Reduces likelihood of ponding and slick or icy conditions
- Helps reduce urban heat island effect
Considerations
- Extra care must be taken where there is water-sensitive subsurface infrastructure
- Only certain soil types are appropriate as sub-bases for infiltration
- Porosity of the pavers can convey harmful chemicals into the soil
- Vegetative growth in joints will occur if there is no regular maintenance
- Sand should not be applied to surface
Application
- Most effective on slopes less than 5%
- Must have adequate sub-surface conditions to detain stormwater and level bottom to allow for uniform infiltration
- Can be proposed for use in parking lane, gutter strip, sidewalk, or plaza area
- Avoid sites where there is potential for soil and groundwater contamination
Design
Specification source: Special Section GI-2.03
- ASTM No. 8, 89, or 9 stone is recommend to fill paver joints. Requires open graded stone infiltration bed
- Bottom of infiltration bed should be at least 2 feet above high water table and 2 feet above bedrock
- Sustainability opportunity: Coat pavers with photocatalytic treatment or high-SRI surface
- Sustainability opportunity: Manufacture pavers using color additives to increase the SRI or incorporate recycled materials
Maintenance
- Use of this material requires a maintenance agreement
- Regular maintenance is required, including vacuuming of surface to restore permeability when joints become clogged
- Unit pavers can become loose over time
- Relatively easy to reset or replace