When It Rains It Drains
One of the most important aspects of landscaping design is the way water is dealt with. Whenever possible, I try to provide a means of allowing rainwater and sprinkler runoff to seep into the ground. This can be accomplished with the use of gravel, decomposed granite and pervious concrete pavement – when a hard, stable surface is required.
Pervious concrete, also know as porous concrete, permeable concrete, no-fines concrete, gap-graded concrete, and enhanced-porosity concrete, is a unique and effective means to address important environmental issues and support green, sustainable growth. By capturing stormwater and allowing it to seep into the ground, porous concrete is instrumental in recharging groundwater, reducing stormwater runoff, and meeting U.S. Environmental Protection Agency (EPA) stormwater regulations. In fact, the use of pervious concrete is among the Best Management Practices (BMPs) recommended by the EPA—and by other agencies and geotechnical engineers across the country—for the management of stormwater runoff on a regional and local basis.
This pavement technology creates more efficient land use by eliminating the need for retention ponds, swales, and other stormwater management devices. In doing so, pervious concrete has the ability to lower overall project costs on a first-cost basis.
In pervious concrete, carefully controlled amounts of water and cementitious materials are used to create a paste that forms a thick coating around aggregate particles. A pervious concrete mixture contains little or no sand, creating a substantial void content. Using sufficient paste to coat and bind the aggregate particles together creates a system of highly permeable, interconnected voids that drains quickly.
While pervious concrete can be used for a surprising number of applications, its primary use is in pavement.