Permeable Paver for Parking: Project Showcases How Clay Brick Pavers Can Maximize Drainage and Aesthetics
You never get a second chance to make a first impression, whether you are a potential new employee--or a parking lot.
Officials in Annapolis, Md, certainly knew the latter. The parking lot for Gotts Court--the Annapolis & The Chesapeake Bay Visitor's Center--was made of asphalt, was worn down, and didn't drain properly. In the summer that meant ankle-deep puddles; in the winter that meant ice, possible slips and falls, and the potential for lawsuits.
The lot was also a contradiction in terms: the place where you were supposed to park at a visitor's center was often inaccessible. The only way in was through a parking garage. When the garage was deemed full--due in part to spaces set aside for monthly pass-holders--it was closed off, which meant that passing motorists could occasionally see an empty parking lot, but couldn't get to it. In addition, from an aesthetic point of view, asphalt and concrete curbing didn't fit in an open space in the middle of one of the most historic cities in the United States.
All in all, the parking lot in front of the welcome center wasn't very welcoming.
Landscape architect Shelley Rentsch, RLA, ASLA, who is a partner in Annapolis Landscape Architects, resolutely set out to address all of the problems. Reorienting the entrance meant that there would be better access; and specifying clay brick permeable pavers instead of asphalt better complemented the surrounding red clay brick buildings, some of which date from Colonial times.
That left the drainage. Rentsch designed in a permeable paver drainage system using specially designed StormPave pavers. Made to resemble conventional English Edge pavers, StormPave has a 1/4-inch joint width so that water can infiltrate the system where it is naturally filtered as it dissipates into the ground instead of washing surface pollutants to nearby storm drains or waterways.
"We went about it to create a people place, and it was more about that than it was about the engineering," said Rentsch. "The aesthetics, the engineering and the environment should come together every time."
Underneath the pavers, the installation is remarkably different than a conventional installation, which uses crusher run and sand. Graded aggregates without fine particles are used, with larger aggregates on the sub base, and then progressively smaller aggregates layered atop them. Finally, the pavers are placed atop the smallest aggregates, which are also swept into the spaces between the pavers.
In the Annapolis project, rainwater falls on the pavers, fills the spaces in the aggregate underneath them, and is directed underground to six rain gardens that are on the edges of the property. …