What is permeable pavement and what does it have to do with brick?
/Permeable pavements are the hard surfaces of roads, parking lots, driveways, and sidewalks that would normally shed storm water quickly, except that they are uniquely designed to absorb and infiltrate water that falls on them. This infiltration can be achieved with modified materials, like porous asphalt that allows water to seep through it, or with gaps between small pavement units that direct water to a porous bedding material below.
Permeable clay brick pavement does the latter. The brick units themselves aren’t typically modified to absorb greater amounts of water, rather they are laid in a fashion that lets water flow around them and down to the permeable layer. Some clay pavers are designed with lugs — expanded ridges — on their sides to ensure that the proper gap between units is maintained when the pavers are put in place.
All of this is important because increases in stormwater runoff result from increases in hard surfaces — parking lots, sidewalks, roads, and even compacted soil topped with turf grass. Without mitigating measures, development and construction increase the volume and rate of stormwater runoff into streams, lakes, and sewers, taking sediment and pollutants with it. Flooding risk also rises as waterways and natural water-holding areas are quickly filled to capacity.
The solution is to hold more (or all) of the water that falls on a developed property right there, so it has time to infiltrate into the soil. Detention/retention ponds hold water on site for long periods, but they are costly to construct and require lots of space. But buildings usually come with pavement, and turning those hard surfaces into water-infiltrating sponges can go a long way toward good stormwater management within the same square footage that would have been required for the development anyway. As an added bonus, permeable pavements often generate credit toward green building credentials like the USGBC’s LEED program.
So permeable pavements can be a big part of the stormwater solution, but there remains a very important question. Can they do it with style? Clay brick pavers can. The last thing you want to do with a beautiful project you designed is to surround it with purely utilitarian paving. Clay pavers look as beautiful underfoot as they do in the wall, and they can last literally for a century or more. When was the last time you considered the surrounding pavement, not just the building at the center of it, to be part of your legacy as a designer?
