44 csengineermag.com MAY 2019
Permeable Pavements Capture Stormwater at its Source
With increases in surface runoff from new construction and expanding hard pavements, the capacity of existing stormwater systems are
being pushed beyond their limits. As a result, environmental regulations limiting runoff continue to increase the demand for access roads,
parking areas, road shoulders and walkways that are porous.
Land development initiatives such as GI and LID are also helping to escalate the use of low environmental impact products to reduce storm-
water naturally at its source. Porous and permeable pavements offer immediate infiltration at the point of contact—not only reducing runoff,
but reducing the size/need for stormwater infrastructure. Gravel pavers contain open-graded aggregate for fast infiltration without any
traffic restrictions. Even the pavement layer acts as stormwater detention. Grass pavers are designed to protect turf from damage caused by
occasional traffic. Both can receive runoff from adjacent hard pavements, and store predicted stormwater in the base for natural percolation.
Design Support & Resources for Walls & Pavements
Selection of retaining wall type is influenced by a number of criteria
(e.g. surcharge loadings, wall height and batter, soil conditions, space
accessibility). A free project evaluation from the manufacturer helps
determine design feasibility.
A downloadable porous pavement interactive tool is also available to
help designers determine best options for site conditions, stormwa-
ter requirements, and expected use.
