Permeable pavers are well suited for use in commercial and industrial areas, such as parking
lots, storage yards, and loading dock areas. They are also very effective for paved
surfaces that serve primarily pedestrian traffic - for example, building entryways, plazas and
patios. The photographs above demonstrate some examples in North Carolina - a Department of Motor
Vehicle lot in Bogue Banks and an outdoor patio in Wrightsville Beach.
1
The environmental benefits of these permeable pavers include increased water conservation and
improved water quality. For example, in the mid-1990s, as part of their commitment to
conservation in an area of the country
which is subject to droughts, the
Castaic Lake Water Agency of southern California used permeable interlocking concrete
pavers when building the light-duty parking areas of their new water treatment plant.
2 Existing concrete from the site was crushed
and recycled to create the parking lot's base, and the permeable paver system was designed to
allow infiltration into the existing soils and drainage towards landscaped islands. In this way,
the parking lot also functioned as an effective component of a drought-tolerant landscape.
With an emphasis on water quality, the Naval District Washington
innovatively applied permeable interlocking concrete paving blocks during its retrofit of an
existing parking lot.3 As part of an overall initiative to
help maintain and restore the water quality of the Chesapeake Bay and the Anacostia and
Potomac Rivers, permeable pavers were installed between the central rows of the parking
lot. This permeable paver strip, shown in the photograph below, required minimal disturbance
and maintained parking spaces at existing numbers. It was designed to intercept preferential
stormwater pathways and to treat, at a minimum, the first one-half inch of rain from the
surrounding impervious parking surfaces. Pollutants are filtered and runoff volume and timing are
controlled before discharge of the water to the Anacostia River occurs through the existing storm
sewers. LID retrofits such as this are crucial in impervious areas that abut directly to the
waterways. The close-up photograph on the right emphasizes the proximity of the parking lot to
the river, where untreated runoff has caused severe water pollution problems.
Similar stormwater rehabilitation projects to improve water quality have been undertaken by the
Florida Water Management District in Tampa Bay, Florida's largest
open water estuary.4 A combination roadway and parking area in
North Redington Beach was retrofit with over 9,000 square feet of porous concrete and two 150-foot
underdrains during the Bath Club Concourse Stormwater Rehabilitation Project. Before the retrofit,
stormwater runoff flowed directly into a single storm sewer, carrying its full load of nonpoint
source pollutants directly to Boca Ciega Bay. Besides maximizing the infiltration of stormwater
runoff, the project also demonstrated an innovative way to improve the quality of stormwater runoff
in highly urbanized areas where conventional stormwater treatment practices, such as detention
ponds, are often prohibitively expensive due the high cost of land.
In institutional settings, grass and soil-filled permeable pavers can provide an aesthetic and
functional alternative to traditional pavement. Friends University
in Wichita, Kansas, made use of this Low Impact Development practice when, as part of their
renovation of a historic building on campus, they removed the large driveway leading up to the
building's main entrance.5 They replaced it with a system of
GEOBLOCK® interlocking plastic cells, which are made up of 98% post consumer recycled materials
and filled with topsoil and vegetation. The result was a permeable surface with a lawn appearance,
yet one that is capable of bearing heavy emergency or maintenance vehicle loads and providing
protection against soil compaction and rutting.
In general, parking lots serve as one of the primary examples for the application of permeable
pavers. A mall in Connecticut has made use of a four-acre reinforced grass parking lot with a
submerged tank to store stormwater and reuse it in turf irrigation.6
In Savannah, Georgia, numerous parking lot locations - from libraries and doctor's offices to
local businesses - have chosen to apply pervious paving.7
Gravel-filled or soil and grass-filled plastic cells, interlocking concrete paver blocks, and
porous concrete are all suitable for parking areas depending on frequency of use and traffic
loads. Some creative designs include a combination of gravel-filled cells or interlocking blocks
applied to the parking aisles and turf in the parking stalls.
2 Photographs and project information from the UNI-GROUP U.S.A.
Rio Vista Water Treatment Plant Uni Eco-Stone® Case Study. See
http://www.uni-groupusa.org for more information.
4 U.S. Environmental Protection Agency Office of Wetlands, Oceans
and Watersheds Assessment and Watershed Protection Division Nonpoint Source Control, 1994:
Section 319 Nonpoint Source Success Stories Vol. I, No. 841-S-94-004. Accessible at:
http://www.epa.gov/owow/NPS/Section319I/ .
5 Presto Products Company, 1997: Geoblock® Porous Pavement System -
Friends University Uses Porous Pavement System for Renovation of Davis Hall. Accessible at
http://www.prestogeo.com.
7 Krueger, G., 2000: Pervious paving offers one solution to city's
flooding problem. Savannah Morning News, web posted February 12, 2000. Search the News
archives for the Local section at
http://www.savannahnow.com/.
which is subject to droughts, the
Castaic Lake Water Agency of southern California used permeable interlocking concrete
pavers when building the light-duty parking areas of their new water treatment plant.
In institutional settings, grass and soil-filled permeable pavers can provide an aesthetic and
functional alternative to traditional pavement. Friends University
in Wichita, Kansas, made use of this Low Impact Development practice when, as part of their
renovation of a historic building on campus, they removed the large driveway leading up to the
building's main entrance.