Permeable Interlocking Concrete Paver (PICP)

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)


  • 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


  • 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


  • 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


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


  • 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